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[Michael Scally MD]

The hippocampus is a major component of the brains of humans and other mammals. It belongs to the limbic system and plays important roles in long-term memory and spatial navigation. Like the cerebral cortex, with which it is closely associated, it is a paired structure, with mirror-image halves in the left and right sides of the brain. In humans and other primates, the hippocampus is located inside the medial temporal lobe, beneath the cortical surface. It contains two main interlocking parts: Ammon's horn and the dentate gyrus. [ame="http://en.wikipedia.org/wiki/Hippocampus"]Hippocampus - Wikipedia, the free encyclopedia@@AMEPARAM@@/wiki/File:Gray739-emphasizing-hippocampus.png" class="image"><img alt="Gray739-emphasizing-hippocampus.png" src="http://upload.wikimedia.org/wikipedia/commons/thumb/2/2e/Gray739-emphasizing-hippocampus.png/200px-Gray739-emphasizing-hippocampus.png"@@AMEPARAM@@commons/thumb/2/2e/Gray739-emphasizing-hippocampus.png/200px-Gray739-emphasizing-hippocampus.png[/ame]

Deterioration of the hippocampus precedes and leads to memory impairment in late adulthood. Strategies to fight hippocampal loss and protect against the development of memory impairment has become an important topic in recent years from both scientific and public health perspectives. Physical activity, such as aerobic exercise, has emerged as a promising low cost treatment to improve neurocognitive function that is accessible to most adults and is not plagued by intolerable side effects often found with pharmaceutical treatments. Exercise enhances learning and improves retention, which is accompanied by increased cell proliferation and survival in the hippocampus of rodents.

Aerobic exercise training increases gray and white matter volume in the prefrontal cortex of older adults and increases the functioning of key nodes in the executive control network. Greater amounts of physical activity are associated with sparing of prefrontal and temporal brain regions over a 9-y period, which reduces the risk for cognitive impairment. Further, hippocampal and medial temporal lobe volumes are larger in higher-fit older adults, and larger hippocampal volumes mediate improvements in spatial memory. Exercise training increases cerebral blood volume and perfusion of the hippocampus, but the extent to which exercise can modify the size of the hippocampus in late adulthood remains unknown.

To evaluate whether exercise training increases the size of the hippocampus and improves spatial memory, researchers designed a single blind, randomized controlled trial in which adults were randomly assigned to receive either moderate-intensity aerobic exercise 3 d/ wk or stretching and toning exercises that served as a control. Researchers predicted that 1 y of moderate-intensity exercise would increase the size of the hippocampus and that change in hippocampal volume would be associated with increased serum Brain-Derived Neurotrophic Factor (BDNF) and improved memory function.


Erickson KI, Voss MW, Prakash RS, et al. Exercise training increases size of hippocampus and improves memory. Proceedings of the National Academy of Sciences. Exercise training increases size of hippocampus and improves memory — PNAS

The hippocampus shrinks in late adulthood, leading to impaired memory and increased risk for dementia. Hippocampal and medial temporal lobe volumes are larger in higher-fit adults, and physical activity training increases hippocampal perfusion, but the extent to which aerobic exercise training can modify hippocampal volume in late adulthood remains unknown. Here we show, in a randomized controlled trial with 120 older adults, that aerobic exercise training increases the size of the anterior hippocampus, leading to improvements in spatial memory. Exercise training increased hippocampal volume by 2%, effectively reversing age-related loss in volume by 1 to 2 y. We also demonstrate that increased hippocampal volume is associated with greater serum levels of BDNF, a mediator of neurogenesis in the dentate gyrus. Hippocampal volume declined in the control group, but higher preintervention fitness partially attenuated the decline, suggesting that fitness protects against volume loss. Caudate nucleus and thalamus volumes were unaffected by the intervention. These theoretically important findings indicate that aerobic exercise training is effective at reversing hippocampal volume loss in late adulthood, which is accompanied by improved memory function.

 

[Michael Scally MD]

The world is ageing rapidly, and accompanying this demographic transition will be a significant increase in the number of people with dementia, a condition that will affect the developing world more greatly than the developed world, in both absolute numbers and proportional increase. The human and financial costs of this condition have, not surprisingly, been of concern to older people, their families and policy makers around the world as they grapple with what will eventually be a major cause of life years lost to disability. The search is on for safe, effective and hopefully, affordable ways to prevent this common and devastating condition of older people.


Flicker L, Ambrose TL, Kramer AF. Why so negative about preventing cognitive decline and dementia? The jury has already come to the verdict for physical activity and smoking cessation. British Journal of Sports Medicine. Why so negative about preventing cognitive decline and dementia? The jury has already come to the verdict for physical activity and smoking cessation -- Flicker et al. -- British Journal of Sports Medicine

 

[Michael Scally MD]

Athletes use dietary supplements (DS) in order to increase energy, maintain strength, enhance performance, maintain health and immune system and prevent nutritional deficiencies. A recent increase in DS use has been observed in various sports and especially among elite athletes. There are several studies estimating that supplement use among athletes is common and varies between 59 to 88% multivitamins, minerals, proteins and energy drinks being most common products being consumed.

Most supplement users consume more than one product and the amount of supplements used varies between age groups, gender and different sports. Norwegian study reported a great difference of supplement use between different sport groups: power sport athletes had the most frequent use of supplemental creatine, proteins/ amino acids, vitamins and minerals while cross- country skiers had the most frequent intake of iron, vitamin C and fish oils.

Athletes are willing to use many kinds of dietary supplements, although researches haven´t been able to prove that most supplements perform as claimed. In their recent statement, American dietetic association (ADA) lists ergogenic aids into four groups according to their safety and efficiency:

1. those that perform as claimed;

2. those that may perform as claimed but for which there is insufficient evidence of efficacy at this time;

3. those that do not perform as claimed; and

4. those that are dangerous, banned, or illegal and, therefore, should not be used.

Group one contains creatine, caffeine, sport drinks, gels and bars, sodium bicarbonate and proteins and amino acids. On the contrary, group three includes majority of the ergogenic aids currently on the market including widely used ginseng and branched chain amino acids. Except for one study, no previous follow-up studies exist on trending athletes DS use. In this study, it was interesting to see whether the report concerning purity of dietary supplements made by the International Olympic Committee had an affect on elite Finnish athletes use of DS.

The aim of this study was to assess the frequency of use of dietary supplements among large sample of elite Finnish athletes and to evaluate possible trends in DS use between 2002 and 2009. DS use has not been reported previously in elite Finnish athletes.


Heikkinen A, Alaranta A, Helenius I, Vasankari T. Use of dietary supplements in Olympic athletes is decreasing: a follow-up study between 2002 and 2009. Journal of the International Society of Sports Nutrition 2011;8(1):1. http://www.jissn.com/content/pdf/1550-2783-8-1.pdf

BACKGROUND: The aim of this study was to assess the frequency of use of dietary supplements (DS) among large sample of elite Finnish athletes and to describe possible changes in dietary supplement use between the years 2002 and 2009.

Methods: A prospective follow-up study was conducted in Olympic athletes. The first survey was conducted on Olympic athletes in 2002 (N=446) and the follow- up study was conducted between May 2008 and June 2009 (N=372).

Results: In 2002, a total of 81% of the athletes used dietary supplements (a mean of 3.37 +/- 3.06 DS per user) and in 2009, a total of 73% of the athletes (a mean of 2.60 +/- 2.69 per DS user) used them. After adjusting for age-, sex- and sport type, the OR (95% confidence interval, CI) for use of any dietary supplement was significantly less in 2009 as compared with 2002 results (OR, 0.62; 95% CI, 0.43-0.90). Decrease in DS use was observed in all supplement subgroups (vitamins, minerals, nutritional supplements). Athletes in speed and power events and endurance events reported use of any dietary supplement significantly more often than team sport athletes both in 2002 and 2009. In year 2009, the frequency of all dietary supplement use increased when athlete's age increased and the increase was significant in older age groups: of the athletes under 21 years 63%, 21-24 years 83% and over 24 years 90% consumed nutritional supplements.

Conclusions: Based in our study, there seems to be a lowering trend of dietary supplement use among elite Finnish athletes although differences between sport subgroups and age groups are considerable.

 

[Michael Scally MD]

Diet soda tied to stroke risk, but reasons unclear
http://news.yahoo.com/s/ap/20110209/ap_on_he_me/us_med_stroke_diet_soda

LOS ANGELES – It's far from definitive proof, but new research raises concern about diet soda, finding higher risks for stroke and heart attack among people who drink it everyday versus those who drink no soda at all.

The beverage findings should be "a wakeup call to pay attention to diet sodas," said Dr. Steven Greenberg. He is a Harvard Medical School neurologist and vice chairman of the International Stroke Conference in California, where the research was presented on Wednesday.

A simple solution, health experts say, is to drink water instead.

Doctors have no chemical or biological explanation for why diet soda may be risky. It could be that people who drink lots of it also fail to exercise, weigh more, drink more alcohol or have other risk factors like high blood pressure and smoking. However, the researchers took these and many other factors into account and didn't see a change in the trend.

"It's reasonable to have doubts, because we don't have a clear mechanism. This needs to be viewed as a preliminary study," said lead researcher Hannah Gardener of the University of Miami.

But for those trying to cut calories, "diet soft drinks may not be an optimal substitute for sugar-sweetened beverages," she said.

The numbers come from the Northern Manhattan study, which enrolled about 2,500 adults over 40 in the New York area from 1993 to 2001 through random phone calls. Half are Hispanic and one-fourth are black, making it one of the few studies to look at these risks in minorities, who have higher rates of stroke.

Participants filled out a standard survey about their diets at the start of the study, and their health was tracked for nearly 10 years. In that time there were 559 strokes or heart attacks, 338 of them fatal.

Daily diet soda drinkers (there were 116 in the study) had a 48 percent higher risk of stroke or heart attack than people who drank no soda of any kind (901 people, or 35 percent of total participants). That's after taking into account rates of smoking, diabetes, waistline size and other differences among the groups.

No significant differences in risk were seen among people who drank a mix of diet and regular soda.

Earlier studies have tied diet and regular soda consumption to greater risk of diabetes and a group of weight-related problems called the metabolic syndrome.

Some diet soda critics have suggested it can promote a sweet tooth, affecting behavior and how much of a person's diet comes from sugary sources rather than healthier fruits, vegetables and grains.

These sorts of studies just observe groups of people and are not strong enough evidence to prove risk.

"It's too preliminary to suggest any dietary advice," but other big studies should look at this question, Gardener said.

Greenberg, of the stroke association, called it "a real-world" look at possible risk.

Dr. Maureen Storey, senior vice president of science policy for the American Beverage Association, said in a statement that there is no evidence "that diet soda uniquely causes increased risk of vascular events or stroke."

"The body of scientific evidence does show that diet soft drinks can be a useful weight management tool, a position supported by the American Dietetic Association. Thus, to suggest that they are harmful with no credible evidence does a disservice to those trying to lose weight or maintain a healthy weight."

The beverage group's statement also noted researchers didn't adjust their results for family history of stroke. Gardener, the researcher, said that's not "a substantial weakness."

The same federally funded study also looked at a more conventional health risk — salt. It found higher risks for people eating more than 1,500 milligrams a day. That's the limit the American Heart Association recommends, but last week's new dietary guidelines from the government say it's OK to have a little more.

Researchers found that stroke risk rose 16 percent for every 500 milligrams of salt consumed each day. Those who took in 4,000 or more milligrams of salt had more than 2.5 times greater risk of stroke compared to those who limited themselves to 1,500 milligrams.

A teaspoon of salt contains about 2,300 milligrams of sodium. About three-fourths of the salt we eat, though, comes from processed foods, especially tomato sauce, soups, condiments, and canned foods.


Dietary Sodium Intake is a Risk Factor for Incident Ischemic Stroke: The Northern Manhattan Study (NOMAS) [Abstract 25]

Hannah Gardener, Tatjana Rundek, Clinton Wright, Univ of Miami Miller Sch of Medicine, Miami, FL; Norbelina Disla, Mitchell S Elkind, Columbia Univ, New York, NY; Ralph L Sacco; Univ of Miami Miller Sch of Medicine, Miami, FL

The American Heart Association (AHA) recommends limiting sodium intake to less than 1500 mg daily to achieve ideal cardiovascular health. Although dietary sodium intake has been linked to vascular disease by direct relationship to the development of hypertension, few studies have supported an association between sodium intake and risk of ischemic stroke. The study population included participants of the Northern Manhattan Study, a multi-ethnic population based cohort study of stroke-free individuals to examine the incidence and risk factors for stroke. Participants completed a baseline food frequency questionnaire and total daily sodium intake was calculated from responses using DIETSYS software. Sodium intake was evaluated continuously and by five levels of consumption: variables: age, sex, race/ethnicity, education, alcohol use, physical activity, total daily caloric consumption, smoking, diabetes, hypercholesterolemia, hypertension, and previous cardiac disease. Of 2657 participants who completed a food questionnaire with valid diet data, the mean age was 69 +/- 10 years, 64% were women, 21% white non-Hispanic, 53% Hispanic, and 24% black non-Hispanic. The mean daily sodium intake was 3031 mg +/- 1470, median 2787 mg (IQR 1966-3815 mg). Over a mean follow-up of 9.7 years, 187 ischemic strokes occurred. When dietary sodium intake was modeled continuously, a 16% increased risk of ischemic stroke was observed for each 500 mg increase in daily consumption (95% CI: 1.06-1.27). Subjects who consumed >4000 mg sodium daily had an increased risk of ischemic stroke (adjusted HR 2.29; 95% CI: 1.07-4.92) as compared to those who consumed chemic stroke. The new AHA strategic dietary goals will help promote ideal cardiovascular, as well as brain health. This evidence may be used in campaigns aimed at reducing cardiovascular disease risk by targeting dietary behavior.

http://stroke.ahajournals.org/cgi/reprint/STR.0b013e3182074d88v1.pdf

 

[Michael Scally MD]

The purposes of this study were to evaluate the prevalence of vitamin D insufficiency in National Collegiate Athletic Association (NCAA) Division I athletes throughout the academic year and to determine whether circulating concentrations of 25(OH)D are related to vitamin D intake, sun exposure, and body composition. A secondary purpose was to evaluate whether 25(OH)D concentration is linked to bone density, development of overuse or inflammatory injuries, and/or incidence of frequent illness.

Researchers hypothesized that athletes participating in indoor sports would have lower 25(OH)D concentrations compared with those participating in outdoor sports. Within the entire group of athletes, they further hypothesized that sun exposure, sunscreen use, and vitamin D intake (from food and supplements) would be predictive of 25(OH)D concentrations. In addition, they hypothesized that lower concentrations of 25(OH)D at any time point throughout the year would increase risk for low bone density, overuse and/or inflammatory injuries, and frequent illness.


Halliday T, Peterson N, Thomas J, Kleppinger K, Hollis B, Larson-Meyer D. Vitamin D Status Relative to Diet, Lifestyle, Injury and Illness in College Athletes. Med Sci Sports Exerc. Vitamin D status relative to diet, lifestyle, inju... [Med Sci Sports Exerc. 2011] - PubMed result

Vitamin D deficiency is endemic in the general population; however, there is much to be learned about the vitamin D status of athletes.

PURPOSE: To assess the prevalence of vitamin D insufficiency in collegiate athletes and determine whether 25(OH)D concentrations are related to vitamin D intake, sun exposure, body composition, and risk for illness or athletic injury.

METHODS: 25(OH) vitamin D concentrations were measured in 41 (18 male/23 female) athletes (12 indoor/29 outdoor) throughout the academic year. Dietary intake and lifestyle habits were assessed via questionnaire, bone density was measured by DEXA and injury and illness were documented as part of routine care.

RESULTS: 25(OH)D concentrations changed across time (P=0.001) and averaged 49.0+/-16.6, 30.5+/-9.4 and 41.9+/-14.6 ng/mL in the fall, winter and spring, respectively, and were higher in outdoor versus indoor athletes in the fall (P <0.05). Using 40 ng/mL as the cutoff for optimal status, 75.6 %, 15.2% and 36.0% of athletes had optimal status in the fall, winter and spring, respectively. 25(OH)D concentrations were significantly (P <0.05) correlated with multivitamin intake in the winter (r=0.39) and tanning bed use in the spring (r=0.48), however, status was otherwise not related to intake, lifestyle factors or body composition. 25(OH)D concentrations in the spring (r=-0.40; P=0.048) was correlated with frequency of illness.

CONCLUSION: Our results suggest that collegiate athletes can maintain sufficient status during the fall and spring but would benefit from supplementation during the winter to prevent seasonal decreases in 25(OH)D concentrations. Results further suggest that insufficient vitamin D status may increase risk for frequent illness. Future research is needed to identify whether vitamin D status influences injury risk during athletic training/competition.

 

[Michael Scally MD]

Many articles have been published on risk factors for cardiovascular disease, certain cancers, osteoporotic fractures and over all mortality. The mean age at death is increasing, and there are indications that increasing numbers of people are reaching very old age. According to Swedish official statistics, the probability of a Swedish man of 50 years of age of reaching the age of 90 has increased from 12.0% amongst men born in 1913 to 22.9% amongst those born in 1943. It is unclear whether genetic ? family factors or modifiable factors are of primary importance for long life. This issue has recently been addressed by both British and American studies.

In 1963, researchers initiated a prospective study of men born in the year 1913 (i.e. when they were all 50 years old). One in eight of these men reached the age of at least 90. The primary aim was to identify variables of importance for becoming 90 years old and characterize their accuracy as predictors measured in middle age. A secondary aim was to elucidate how the predictive ability of any given variable may change over time, because the influence of strong predictors in the short term may be attenuated over a longer period. Thus, variables measured close to the age of 90 may have stronger predictive capacity than those observed earlier. Researchers investigated the importance of variables measured in middle age and did not compare their predictive ability with variables measured closer to age 90 years, because they considered that this would be a biased comparison. They also studied the probability of reaching 80 years; approximately half of the population reached this age. The difference in predictors for reaching 80 and 90 years is briefly discussed.


Wilhelmsen L, Svärdsudd K, Eriksson H, et al. Factors associated with reaching 90 years of age: a study of men born in 1913 in Gothenburg, Sweden. Journal of Internal Medicine. Factors associated with reaching 90?years of age: ... [J Intern Med. 2010] - PubMed result OR Factors associated with reaching 90years of age: a study of men born in 1913 in Gothenburg, Sweden - Wilhelmsen - 2010 - Journal of Internal Medicine - Wiley Online Library

Objectives. Increasing numbers of people reach old age. We wanted to identify variables of importance for reaching 90 years old and determine how the predictive ability of these variables might change over time.

Setting and subjects. All men in the city of Gothenburg born in 1913 on dates divisible by 3, which is on the 3rd, 6th, 9th etc., were included in the study. Thus, 973 men were invited, and 855 were examined in 1963 at age 50. Further examinations were made at age 54, 60 and 67. Anthropometric data, lifestyle and parental factors, blood pressure, lung function, X-ray of heart and lungs and maximum work performance were recorded. The area under the receiver operating characteristic curve was used to analyse the predictive capacity of a variable.

Results. A total of 111 men (13%) reached 90 years of age, men who reached 90 years were more likely at age 50 to be nonsmokers, consume less coffee, have higher socio-economic status and have low serum cholesterol levels than those who did not reach this age; however, at age 50 or 62, parents’ survival was of no prognostic importance. Variables of greatest importance at higher ages were low blood pressure and measures related to good cardiorespiratory function. In multivariable analysis, including all examinations, being a nonsmoker, consuming small amounts of coffee, having high housing costs at age 50, good maximum working capacity and low serum cholesterol were related to a better chance of survival to age 90.

Conclusions. Low levels of cardiovascular risk factors, high socio-economic status and good functional capacity, irrespective of parents’ survival, characterize men destined to reach the age of 90.

 

[Michael Scally MD]

Neurosteroids are steroids synthesized within the brain and modulate neuronal excitability by rapid non-genomic actions. The term “neurosteroids,” originally coined by the French physiologist Étienne-Émile Baulieu, is now widely used to refer to steroids that are synthesized in the brain. Circulating steroid hormones serve as precursors for the synthesis of neurosteroids, which are produced locally in the hippocampus and other brain structures.

Based on structural features, neurosteroids can be classified as pregnane neurosteroids, such as allopregnanolone and allotetrahydrodeoxycorticosterone (THDOC), androstane neurosteroids, such as androstanediol and etiocholanolone, and sulfated neurosteroids, such as pregnenolone sulfate (PS) and dehydroepiandrosterone sulfate (DHEAS). Steroid hormones have long been recognized to have sedative, anesthetic, and anti-seizure properties in animals and humans. Studies during the past two decades have uncovered that progesterone and deoxycorticosterone (DOC) serve as precursors for the endogenous neurosteroids allopregnanolone (5?-pregnane-3?-ol-20-one) and THDOC (5?-pregnane-3?,21-diol-20-one), respectively. Testosterone-derived androgens such as androstanediol (5?-androstane-3?,17?-diol) and estradiol can be considered as neurosteroids.

Generally, the acute effects of neurosteroids are not related to interactions with classical steroid hormone receptors that regulate gene transcription. Moreover, neurosteroids are not themselves active at intracellular steroid receptors. They modulate brain excitability primarily by interaction with neuronal membrane receptors and ion channels, principally GABA-A receptors. Neurosteroids are endogenous regulators of neuronal excitability, and therefore provide tremendous opportunities for developing therapeutic approaches. This chapter reviews the biosynthesis, mechanisms, pharmacology and therapeutic potentials of neurosteroids and their synthetic analogs and their role in sex differences in susceptibility to brain disorders.


Reddy DS. Neurosteroids: endogenous role in the human brain and therapeutic potentials. Prog Brain Res 2010;186:113-37. Neurosteroids: endogenous role in the human brain ... [Prog Brain Res. 2010] - PubMed result

This chapter provides an overview of neurosteroids, especially their impact on the brain, sex differences and their therapeutic potentials. Neurosteroids are synthesized within the brain and rapidly modulate neuronal excitability. They are classified as pregnane neurosteroids, such as allopregnanolone and allotetrahydrodeoxycorticosterone, androstane neurosteroids, such as androstanediol and etiocholanolone, and sulfated neurosteroids such as pregnenolone sulfate. Neurosteroids such as allopregnanolone are positive allosteric modulators of GABA-A receptors with powerful anti-seizure activity in diverse animal models. Neurosteroids increase both synaptic and tonic inhibition. They are endogenous regulators of seizure susceptibility, anxiety, and stress. Sulfated neurosteroids such as pregnenolone sulfate, which are negative GABA-A receptor modulators, are memory-enhancing agents. Sex differences in susceptibility to brain disorders could be due to neurosteroids and sexual dimorphism in specific structures of the human brain. Synthetic neurosteroids that exhibit better bioavailability and efficacy and drugs that enhance neurosteroid synthesis have therapeutic potential in anxiety, epilepsy, and other brain disorders. Clinical trials with the synthetic neurosteroid analog ganaxolone in the treatment of epilepsy have been encouraging. Neurosteroidogenic agents that lack benzodiazepine-like side effects show promise in the treatment of anxiety and depression.

 

[Michael Scally MD]

The purpose of the present study was (a) to assess the efficacy of a supplement containing a mixture of carbohydrates (dextrose, maltodextrin, and fructose), yet a lower total carbohydrate content, and a moderate amount of protein (MCP, 3.0%CHO, 1.2% PRO), in extending time to exhaustion (TTE), and (b) to determine if muscle damage would be reduced by the protein-containing supplement. Researchers hypothesized that TTE would be extended and muscle damage reduced with the MCP supplement compared to CHO, despite the MCP supplement containing 50% less carbohydrate and 30% fewer calories.


Ferguson-Stegall L, McCleave EL, Ding Z, et al. The effect of a low carbohydrate beverage with added protein on cycling endurance performance in trained athletes. J Strength Cond Res 2010;24(10):2577-86. The effect of a low carbohydrate beverage with add... [J Strength Cond Res. 2010] - PubMed result

Ingesting carbohydrate plus protein during prolonged variable intensity exercise has demonstrated improved aerobic endurance performance beyond that of a carbohydrate supplement alone. The purpose of the present study was to determine if a supplement containing a mixture of different carbohydrates (glucose, maltodextrin, and fructose) and a moderate amount of protein given during endurance exercise would increase time to exhaustion (TTE), despite containing 50% less total carbohydrate than a carbohydrate-only supplement. We also sought post priori to determine if there was a difference in effect based on percentage of ventilatory threshold (VT) at which the subjects cycled to exhaustion.

Fifteen trained male and female cyclists exercised on 2 separate occasions at intensities alternating between 45 and 70% VO2max for 3 hours, after which the workload increased to approximately 74-85% VO2max until exhaustion. Supplements (275 mL) were provided every 20 minutes during exercise, and these consisted of a 3% carbohydrate/1.2% protein supplement (MCP) and a 6% carbohydrate supplement (CHO).

For the combined group (n = 15), TTE in MCP did not differ from CHO (31.06 +/- 5.76 vs. 26.03 +/- 4.27 minutes, respectively, p = 0.064). However, for subjects cycling at or below VT (n = 8), TTE in MCP was significantly greater than for CHO (45.64 +/- 7.38 vs. 35.47 +/- 5.94 minutes, respectively, p = 0.006). There were no significant differences in TTE for the above VT group (n = 7).

Our results suggest that, compared to a traditional 6% CHO supplement, a mixture of carbohydrates plus a moderate amount of protein can improve aerobic endurance at exercise intensities near the VT, despite containing lower total carbohydrate and caloric content.

 

[Michael Scally MD]

This review summarizes recent knowledge on the expanding area of nuts and berries and heart health. Effects of consumption of these special foods on related outcomes, such as obesity and diabetes, and other health aspects will also be addressed.


Ros E, Tapsell LC, Sabate J. Nuts and berries for heart health. Curr Atheroscler Rep 2010;12(6):397-406. Nuts and berries for heart health. [Curr Atheroscler Rep. 2010] - PubMed result

Nuts are nutrient-dense foods with complex matrices rich in unsaturated fatty acids and other bioactive compounds, such as L-arginine, fiber, minerals, tocopherols, phytosterols, and polyphenols. By virtue of their unique composition, nuts are likely to beneficially impact heart health. Epidemiologic studies have associated nut consumption with a reduced incidence of coronary heart disease in both genders and diabetes in women. Limited evidence also suggests beneficial effects on hypertension and inflammation. Interventional studies consistently show that nut intake has a cholesterol-lowering effect and there is emerging evidence of beneficial effects on oxidative stress, inflammation, and vascular reactivity. Blood pressure, visceral adiposity, and glycemic control also appear to be positively influenced by frequent nut consumption without evidence of undue weight gain. Berries are another plant food rich in bioactive phytochemicals, particularly flavonoids, for which there is increasing evidence of benefits on cardiometabolic risk that are linked to their potent antioxidant power.

 

[Michael Scally MD]

Obesity is associated with reduced pulsatile and stimulated growth hormone (GH) secretion. In addition, obesity is associated with reduced testosterone levels in men. However, relatively little is known regarding the interrelationship of these axes in obesity. In the present study, researchers demonstrate a significant relationship between reduced secretion of total and FT and peak stimulated GH in otherwise healthy normal weight and obese subjects. They further demonstrate this relationship is most likely mediated by adiposity rather than a direct effect of reduced testosterone on GH secretion. They also demonstrate that the significant relationship between reduced peak stimulated GH secretion of obesity and carotid intima-media thickness (cIMT) is independent of total or FT as well as traditional cardiovascular disease risk markers.


Makimura H, Stanley TL, Sun N, Connelly JM, Hemphill LC, Grinspoon SK. The relationship between reduced testosterone, stimulated growth hormone secretion and increased carotid intima-media thickness in obese men. Clin Endocrinol (Oxf) 2010;73(5):622-9. The relationship between reduced testosterone, sti... [Clin Endocrinol (Oxf). 2010] - PubMed result

OBJECTIVE: Obesity is associated with reduced testosterone and growth hormone (GH). However, the interrelationship between these axes and their independent contributions to cardiovascular risk is unknown. The objectives of this study were to determine (1) the association between testosterone and GH in obesity, (2) whether excess adiposity mediates this association and (3) the relative contribution of reduced testosterone and GH to increased carotid intima-media thickness (cIMT) in obesity.

DESIGN: Fifty obese men were studied with GH-releasing hormone-arginine testing, and morning free testosterone (FT) was measured by equilibrium dialysis. Metabolic, anthropometric and cardiovascular risk indices, including cIMT were measured. Twenty-six normal weight men served as controls.

RESULTS: Obese subjects demonstrated lower mean (+/-SEM) peak stimulated GH (5.9 +/- 0.6 vs 36.4 +/- 3.9 mug/l; P < 0.0001) and FT (0.41 +/- 0.03 vs 0.56 +/- 0.03 nmol/l; P = 0.0005) compared to controls. GH was significantly associated with FT (r = +0.44; P < 0.0001) and both were inversely related to visceral adipose tissue (VAT) (GH: r = -0.65; P < 0.0001; FT: r = -0.51; P < 0.0001). In multivariate regression analysis controlling for VAT, FT was no longer related to GH. Both GH and FT were associated with cIMT in univariate analysis. However, in multivariate modelling including traditional cardiovascular risk markers, GH (beta = 0.003; P = 0.04) but not FT (P = 0.35) was associated with cIMT.

CONCLUSIONS: These results demonstrate a strong relationship between FT and GH in obesity and suggest that this relationship is more a function of excess adiposity rather than a direct relationship. While reduced FT and GH are both related to increased cIMT, the relationship with reduced GH remains significant controlling for reduced FT and traditional cardiovascular disease risk markers.

 

[Michael Scally MD]

Parr MK, Opfermann G, Geyer H, et al. Seized Designer Supplement named "1-Androsterone": Identification as 3beta-Hydroxy-5alpha-androst-1-en-17-one and its Urinary Elimination. Steroids. Seized Designer Supplement named "1-Androsterone":... [Steroids. 2011] - PubMed result

New analogues of androgens that had never been available as approved drugs are marketed as "dietary supplement" recently. They are mainly advertised to promote muscle mass and are considered by the governmental authorities in various countries, as well as by the World Anti-doping Agency for sport, as being pharmacologically and/or chemically related to anabolic steroids. In the present study, we report the detection of a steroid in a product seized by the State Bureau of Criminal Investigation Schleswig-Holstein, Germany. The product "1-Androsterone" of the brand name "Advanced Muscle Science" was labeled to contain 100mg of "1-Androstene-3b-ol,17-one" per capsule. The product was analyzed underivatized and as bis-TMS derivative by GC-MS. The steroid was identified by comparison with chemically synthesized 3beta-hydroxy-5alpha-androst-1-en-17-one, prepared by reduction of 5alpha-androst-1-ene-3,17-dione with LS-Selectride (Lithium tris-isoamylborohydride), and by nuclear magnetic resonance. Semi-quantitation revealed an amount of 3beta-hydroxy-5alpha-androst-1-en-17-one in the capsules as labeled. Following oral administration to a male volunteer, the main urinary metabolites were monitored. 1-Testosterone (17beta-hydroxy-5alpha-androst-1-en-3-one), 1-androstenedione (5alpha-androst-1-ene-3,17-dione), 3alpha-hydroxy-5alpha-androst-1-en-17-one, 5alpha-androst-1-ene-3alpha,17beta-diol, and 5alpha-androst-1-ene-3beta,17beta-diol were detected besides the parent compound and two more metabolites (up to now not finally identified but most likely C-18 and C-19 hydroxylated 5alpha-androst-1-ene-3,17-diones). Additionally, common steroids of the urinary steroid profile were altered after the administration of "1-Androsterone". Especially the ratios of androsterone/etiocholanolone and 5alpha-/5beta-androstane-3alpha,17beta-diol and the concentration of 5alpha-dihydrotestosterone were influenced. 3alpha-Hydroxy-5alpha-androst-1-en-17-one appears to be suitable for the long-term detection of the steroid (ab-)use, as this characteristic metabolite was detectable in screening up to nine days after a single administration of one capsule.

 

[Michael Scally MD]

This study searched on PubMed (1950 -- 2010), the Cochrane Database and bibliographies of the identified studies, searching for Cochrane reviews and randomized, double-blind, placebo-controlled trials with morbidity and mortality as major outcomes; however, if these data were unavailable, studies with surrogate endpoints such as body weight, lean body mass (LBM) and muscle mass were included.


Woerdeman J, de Ronde W. Therapeutic effects of anabolic androgenic steroids on chronic diseases associated with muscle wasting. Expert Opin Investig Drugs 2011;20(1):87-97. Therapeutic effects of anabolic androgenic steroid... [Expert Opin Investig Drugs. 2011] - PubMed result

INTRODUCTION: A variety of clinical conditions are complicated by loss of weight and skeletal muscle which may contribute to morbidity and mortality. Anabolic androgenic steroids have been demonstrated to increase fat-free mass, muscle mass and strength in healthy men and women without major adverse events and therefore could be beneficial in these conditions.

AREAS COVERED: This review provides an overview of clinical trials with anabolic androgenic steroids in the treatment of chronic diseases including HIV-wasting, chronic renal failure, chronic obstructive lung disease, muscular disease, alcoholic liver disease, burn injuries and post operative recovery. Relevant studies were identified in PubMed (years 1950 - 2010), bibliographies of the identified studies and the Cochrane database.

EXPERT OPINION: Although the beneficial effects of AAS in chronic disorders are promising, clinically relevant endpoints such as quality of life, improved physical functioning and survival were mainly missing or not significant, except for burn injuries. Therefore, more studies are needed to confirm their long term safety and efficacy.

 

[Michael Scally MD]

Increased prenatal testosterone concentration has been shown to be inversely related to finger length, through its association with the Homeobox (Hox) genes. The hox genes are responsible for controlling the development of musculoskeletal, neurological, and gonadal tissue and thus physiological traits that may be beneficial to athletic competition. Expression of the Hox genes can be measured indirectly through the ratio lengths for the second and fourth digits (2D:4D ratio). It is suggested that a low 2D:4D ratio (i.e., the fourth digit is longer than the second digit) is associated not only with greater success in a range of sports, many of which demand high levels of power, endurance, and visual–spatial skills, but also with masculine behaviors such as sensation seeking and dominance behavior. However, there exist a limited number of studies exploring this relationship and its value in determining the potential athleticism of an individual.

Hox gene expression controls both the overall blueprint for growth patterns of the appendicular skeleton (including the fingers and toes) and the development of testes or ovaries, which are ultimately responsible for sex differences. Men and women receive small quantities of testosterone from the mother’s environment in utero, and sex differences, specifically masculinized musculoskeletal, and neurological development, are attributed to higher levels of testosterone in men. This pattern of individual finger lengths is fixed by week 14 of development, so the 2D:4D ratio may be used as a proxy measure of influence of prenatal testosterone.

Increased prenatal testosterone may be an essential precursor for excellence in some sport activities because characteristics affected by testosterone, such as muscle fiber hypertrophy, increased strength, decreased fat mass, and an increase in hematocrit, may also contribute to the success of an athlete. There is also evidence that this prenatal testosterone influences cerebral hemisphere development, which has been linked to characteristics beneficial in some sports. Increased prenatal testosterone appears related to sensation seeking and aggressive behaviors while also facilitating brain development for visual–spatial abilities. A model suggested that prenatal testosterone tends to slow the growth of certain areas of the left hemisphere while enhancing growth of comparable areas in the right hemisphere. Because men generally have higher levels of testosterone, brain growth would favor right hemisphere skills. This pattern of promoting neurologic growth may be advantageous for a masculinized brain and affect predisposition to athleticism, especially in highly dynamic sports that place an emphasis on speed, strength, visual–spatial awareness, aggression, and risk taking.

Researchers assessed the 2D:4D ratios of student who participated in several sports (running, soccer, martial arts, rugby, tennis or squash, swimming, hockey) and concluded that lower 2D:4D ratios were associated with greater achievement and higher athletic attainment. This research has also assessed the 2D:4D ratio in professional sports (soccer) leagues and reported similar findings. Therefore, assessing 2D:4D ratios as an indirect measure of prenatal testosterone concentration may help predict athletic performance. The purpose of this research was to examine the 2D:4D ratio in a male population to explore relationships between division I intercollegiate athletes and nonathletes. Athletes were compared by sport, and to a control sample from the general collegiate population.


Moffit DM, Swanik CB. The Association between Athleticism, Prenatal Testosterone, and Finger Length. J Strength Cond Res. The Association between Athleticism, Prenatal Test... [J Strength Cond Res. 2010] - PubMed result

Research suggests that prenatal levels of testosterone are related to finger length development and traits beneficial to athletic skill, such as power, endurance, visual-spatial skills, or sensation seeking and dominance behavior. In men, the second digit to fourth digit ratio (2D:4D) has been shown to correlate with success in competitive levels of football (soccer), which suggests that the 2D:4D ratio is a possible marker for level of attainment in sport. The purpose of this study was to explore the 2D:4D relationships between sports and make comparisons with nonathletes. A multiple group posttest-only design was used. Participants included 138 male volunteers with 92 intercollegiate National Collegiate Athletic Association division I athletes and 46 nonathletes who were not varsity athletes. The independent variable was group (crew, football, gymnastics, soccer, nonathlete). The dependent variable was the 2D:4D ratio. No significant differences were noted between the athletes and nonathletes (p = 0.182). Significant differences were found among the different groups (p = 0.000), with significantly lower ratios between football and crew (p = 0.000), football and nonathletes (p = 0.030), and gymnastics and crew (p = 0.001). This research provides a stronger level of evidence that the 2D:4D ratio may help indicate potential athleticism or competition-level achievement, but the external validity may be limited to only specific sports.

 

[Michael Scally MD]

Pirola I, Cappelli C, Delbarba A, et al. Anabolic steroids purchased on the Internet as a cause of prolonged hypogonadotropic hypogonadism. Fertil Steril 2010;94(6):2331 e1-3. Anabolic steroids purchased on the Internet as a c... [Fertil Steril. 2010] - PubMed result

OBJECTIVE: To report a case of hypogonadotropic hypogonadism due to the chronic abuse of anabolic steroids purchased over the Internet.

DESIGN: Case report. SETTING: Endocrinology unit of the University of Brescia. PATIENT(S): A 34-year-old man.

INTERVENTION(S): A single dose (100 mug) of triptorelin (triptorelin test).

MAIN OUTCOME MEASURE(S): Clinical symptoms, androgen normalization, levels of serum testosterone, follicle-stimulating hormone, and luteinizing hormone.

RESULT(S): Within 1 month, the patient's serum testosterone was in the normal range, and he reported a return to normal energy and libido.

CONCLUSION(S): The World Anti-Doping Code has proved to be a very powerful and effective tool in the harmonization of antidoping efforts worldwide, but it is insufficient to combat this illegal phenomenon. To tackle the serious side effects caused by doping we believe that it is necessary to increase monitoring and adopt severe sanctions, particularly with regard to Internet sites.

 

[Michael Scally MD]

In 1938, when the US Congress first mandated that medical products demonstrate safety and effectiveness, the law applied only to drugs, not to medical devices. Congress did not give the US Food and Drug Administration (FDA) the authority to regulate all medical devices until 1976, when it amended the Food, Drug, and Cosmetics Act in response to deaths and infertility caused by the Dalkon Shield and other contraceptive intrauterine devices. Congress and the FDA weighed 2 competing goals during passage of this legislation: providing "the public reasonable assurances of safe and effective devices" while avoiding "overregulation" of the industry.

The 1976 law included a premarket approval (PMA) process for devices that is similar to the new drug application process used for pharmaceuticals. Submissions for PMA require extensive testing, including "valid scientific evidence" that "provide reasonable assurance that the device is safe and effective for its intended use." The PMA process was developed as the approval pathway for medical devices that "support or sustain human life, are of substantial importance in preventing impairment of human health, or which present a potential, unreasonable risk of illness or injury."

Thousands of devices were already marketed in 1976, so Congress included an alternative pathway to the PMA known as the 510(k) provision, which was intended to provide a less burdensome route to enable newer versions of existing devices to enter the market. The 510(k) pathway did not require clinical trials or manufacturing inspections to demonstrate safety and efficacy. Instead, the sponsor was required only to demonstrate that the device was substantially equivalent in materials, purpose, and mechanism of action to another device that was already on the market in May 1976. The previous device served as the predicate device with which the new one would be compared. This approach was justified as a way to give manufacturers the opportunity to make small improvements on the devices already on the market and to allow companies with new products to compete with very similar devices without using the more extensive PMA process. If the FDA determined that the product was reasonably safe and effective according to the 510(k) review, it was said to be cleared for market rather than approved.

Former FDA officials explain that in 1976, relatively few medical devices were permanently implanted or intended to sustain life. The 510(k) process was specifically intended for devices with less need for scientific scrutiny, such as surgical gloves and hearing aids. At first, 510(k) reviews were easy for the FDA to conduct because the new devices were so similar to the devices already on the market, but the system was quickly challenged as new devices changed more dramatically and became more complex. The FDA did not have the resources to develop performance standards for new moderate-risk devices or to shift more devices to the much more stringent and time-consuming PMA process.

Instead, the opposite trend occurred. In an era of aggressive deregulation, the Medical Device User Fee and Modernization Act of 2002 (MDUFMA) was passed by Congress, signed by President Bush, and interpreted by the FDA to shift the regulatory standard to "the least burdensome approach in all areas of medical device regulation." Subsequently, the definition of substantially equivalent was modified to include products made from different materials and using a different mechanism of action if they were determined to have a similar safety profile. Since clinical trials are not required for 510(k) clearance, approval of devices would be based on biomaterials testing or other standards. Furthermore, predicate devices no longer were limited to products already on the market prior to May 1976 but could include devices cleared through the 510(k) or PMA process. In recent years, the FDA has used the 510(k) provision as the dominant mechanism for new device clearance, reviewing only 1% of medical devices by its more rigorous PMA process. The present study was designed to examine how often the different approval or clearance processes were used for medical devices that were subsequently recalled for life-threatening problems.


Zuckerman DM, Brown P, Nissen SE. Medical Device Recalls and the FDA Approval Process. Arch Intern Med:archinternmed.2011.30. Arch Intern Med -- Abstract: Medical Device Recalls and the FDA Approval Process, February 14, 2011, Zuckerman et al. 0 (2011): archinternmed.2011.30v1

Background - Unlike prescription drugs, medical devices are reviewed by the US Food and Drug Administration (FDA) using 2 alternative regulatory standards: (1) premarket approval (PMA), which requires clinical testing and inspections; or (2) the 510(k) process, which requires that the device be similar to a device already marketed (predicate device). The second standard is intended for devices that the FDA deems to involve low or moderate risk.

Methods - We analyzed the FDA's high-risk List of Device Recalls from 2005 through 2009. Using FDA data, we determined whether the recalled devices were approved by the more rigorous (PMA) process, the 510(k) process, or were exempt from FDA review.

Results - There were 113 recalls from 2005 through 2009 that the FDA determined could cause serious health problems or death. Only 21 of the 113 devices had been approved through the PMA process (19%). Eighty were cleared through the 510(k) process (71%), and an additional 8 were exempt from any FDA regulation (7%). Cardiovascular devices comprised the largest recall category, with 35 of the high-risk recalls (31%); two-thirds were cleared by the 510(k) process (66%; n = 23). Fifty-one percent of the high-risk recalls were in 5 other device categories: general hospital, anesthesiology, clinical chemistry, neurology, or ophthalmology.

Conclusions - Most medical devices recalled for life-threatening or very serious hazards were originally cleared for market using the less stringent 510(k) process or were considered so low risk that they were exempt from review (78%). These findings suggest that reform of the regulatory process is needed to ensure the safety of medical devices.


Redberg RF, Dhruva SS. Medical Device Recalls: Comment on "Medical Device Recalls and the FDA Approval Process". Arch Intern Med:archinternmed.2011.27. Arch Intern Med -- Medical Device Recalls: Comment on "Medical Device Recalls and the FDA Approval Process", February 14, 2011, Redberg and Dhruva 0 (2011): archinternmed.2011.27v1


Study Cites Lax Regulation of Medical Devices
http://www.nytimes.com/2011/02/15/business/15device.html?hp

 

[Michael Scally MD]

Dietary fiber is defined as the edible parts of plants or analogous carbohydrates that are resistant to digestion and absorption in the human small intestine, with complete or partial fermentation in the large intestine. It has been hypothesized to lower the risk of coronary heart disease, diabetes, some cancers, obesity, and premature death because it is known to (1) improve laxation by increasing bulk and reducing transit time of feces through the bowel; (2) increase excretion of bile acid, estrogen, and fecal procarcinogens and carcinogens by binding to them; (3) lower serum cholesterol levels; (4) slow glucose absorption and improve insulin sensitivity; (5) lower blood pressure; (6) promote weight loss; (7) inhibit lipid peroxidation; and (8) have anti-inflammatory properties.

Studies of dietary fiber in relation to cause-specific death, except death from cardiovascular disease (CVD), are sparse. This study investigated dietary fiber intake in relation to total and cause-specific mortality in a large prospective cohort of men and women in which more than 30 000 deaths occurred during an average of 9 years of follow-up and a wide range of dietary intakes.


Park Y, Subar AF, Hollenbeck A, Schatzkin A. Dietary Fiber Intake and Mortality in the NIH-AARP Diet and Health Study. Arch Intern Med:archinternmed.2011.18. Arch Intern Med -- Abstract: Dietary Fiber Intake and Mortality in the NIH-AARP Diet and Health Study, February 14, 2011, Park et al. 0 (2011): archinternmed.2011.18v1

Background - Dietary fiber has been hypothesized to lower the risk of coronary heart disease, diabetes, and some cancers. However, little is known of the effect of dietary fiber intake on total death and cause-specific deaths.

Methods - We examined dietary fiber intake in relation to total mortality and death from specific causes in the NIH (National Institutes of Health)-AARP Diet and Health Study, a prospective cohort study. Diet was assessed using a food-frequency questionnaire at baseline. Cause of death was identified using the National Death Index Plus. Cox proportional hazard models were used to estimate relative risks and 2-sided 95% confidence intervals (CIs).

Results - During an average of 9 years of follow-up, we identified 20 126 deaths in men and 11 330 deaths in women. Dietary fiber intake was associated with a significantly lowered risk of total death in both men and women (multivariate relative risk comparing the highest with the lowest quintile, 0.78 [95% CI, 0.73-0.82; P for trend, <.001] in men and 0.78 [95% CI, 0.73-0.85; P for trend, <.001] in women). Dietary fiber intake also lowered the risk of death from cardiovascular, infectious, and respiratory diseases by 24% to 56% in men and by 34% to 59% in women. Inverse association between dietary fiber intake and cancer death was observed in men but not in women. Dietary fiber from grains, but not from other sources, was significantly inversely related to total and cause-specific death in both men and women.

Conclusions - Dietary fiber may reduce the risk of death from cardiovascular, infectious, and respiratory diseases. Making fiber-rich food choices more often may provide significant health benefits.

 

[Michael Scally MD]

Obesity Alone Raises Risk of Fatal Heart Attack, Study Finds
Analysis suggests something about carrying extra weight is at play
By Alan Mozes

MONDAY, Feb. 14 (HealthDay News) -- Obese men face a dramatically higher risk of dying from a heart attack, regardless of whether or not they have other known risk factors for cardiovascular disease, a new study reveals.

Continue Reading . . . http://consumer.healthday.com/Article.asp?AID=649876


Logue J, Murray HM, Welsh P, et al. Obesity is associated with fatal coronary heart disease independently of traditional risk factors and deprivation. Heart. http://heart.bmj.com/content/early/2011/01/24/hrt.2010.211201.abstract (Obesity is associated with fatal coronary heart disease independently of traditional risk factors and deprivation -- Logue et al. -- Heart)

Background - The effect of body mass index (BMI) on coronary heart disease (CHD) risk is attenuated when mediators of this risk (such as diabetes, hypertension and hyperlipidaemia) are accounted for. However, there is now evidence of a differential effect of risk factors on fatal and non-fatal CHD events, with markers of inflammation more strongly associated with fatal than non-fatal events.

Objective - To describe the association with BMI separately for both fatal and non-fatal CHD risk after accounting for classical risk factors and to assess any independent effects of obesity on CHD risk.

Methods and results - In the West of Scotland Coronary Prevention Study BMI in 6082 men (mean age 55 years) with hypercholesterolaemia, but no history of diabetes or CVD, was related to the risk of fatal and non-fatal CHD events. After excluding participants with any event in the first 2 years, 1027 non-fatal and 214 fatal CHD events occurred during 14.7 years of follow-up. A minimally adjusted model (age, sex, statin treatment) and a maximally adjusted model (including known CVD risk factors and deprivation) were compared, with BMI 25–27.4 kg/m2 as referent. The risk of non-fatal events was similar across all BMI categories in both models. The risk of fatal CHD events was increased in men with BMI 30.0–39.9 kg/m2 in both the minimally adjusted model (HR=1.75 (95% CI 1.12 to 2.74)) and the maximally adjusted model (HR=1.60 (95% CI 1.02 to 2.53)).

Conclusions - These hypothesis generating data suggest that obesity is associated with fatal, but not non-fatal, CHD after accounting for known cardiovascular risk factors and deprivation.

 

[Michael Scally MD]

I shop at Walmart each week. I am forever astonished and shocked by the money people pay for the drink "Red Bull" and "Five Hour Energy." It just goes to show what a great marketing shtick and a gullible public are willing to believe and buy. I do not think that regulation is the key, but brains is probably a far better solution. Can we regulate brains [propaganda]? LMAO

“Energy drinks” are beverages that contain caffeine, taurine, vitamins, herbal supplements, and sugar or sweeteners and are marketed to improve energy, weight loss, stamina, athletic performance, and concentration. Energy drinks are available in >140 countries and are the fastest growing US beverage market; in 2011, sales are expected to top $9 billion. Half of the energy-drink market consists of children (<12 years old), adolescents (12–18 years old), and young adults (19 –25 years old).

Given the rapidly growing market and popularity among youth, we reviewed the literature to (1) determine what energy drinks are, (2) compile consumption data of energy drinks by children, adolescents, and young adults, (3) compile caffeine and energy-drink overdose data, (4) examine the physiologic effects of the ingredients in energy drinks, (5) identify potential problems of energy drinks among children and adolescents, (6) assess the marketing of energy drinks, (7) report current regulation of energy drinks, and (8) propose educational, research, and regulatory recommendations.


Seifert SM, Schaechter JL, Hershorin ER, Lipshultz SE. Health Effects of Energy Drinks on Children, Adolescents, and Young Adults. Pediatrics. Health Effects of Energy Drinks on Children, Adolescents, and Young Adults -- Seifert et al., 10.1542/peds.2009-3592 -- Pediatrics

Objective - To review the effects, adverse consequences, and extent of energy-drink consumption among children, adolescents, and young adults.

Methods - We searched PubMed and Google using "energy drink," "sports drink," "guarana," "caffeine," "taurine," "ADHD," "diabetes," "children," "adolescents," "insulin," "eating disorders," and "poison control center" to identify articles related to energy drinks. Manufacturer Web sites were reviewed for product information.

Results - According to self-report surveys, energy drinks are consumed by 30% to 50% of adolescents and young adults. Frequently containing high and unregulated amounts of caffeine, these drinks have been reported in association with serious adverse effects, especially in children, adolescents, and young adults with seizures, diabetes, cardiac abnormalities, or mood and behavioral disorders or those who take certain medications. Of the 5448 US caffeine overdoses reported in 2007, 46% occurred in those younger than 19 years. Several countries and states have debated or restricted their sales and advertising.

Conclusions - Energy drinks have no therapeutic benefit, and many ingredients are understudied and not regulated. The known and unknown pharmacology of agents included in such drinks, combined with reports of toxicity, raises concern for potentially serious adverse effects in association with energy-drink use. In the short-term, pediatricians need to be aware of the possible effects of energy drinks in vulnerable populations and screen for consumption to educate families. Long-term research should aim to understand the effects in at-risk populations. Toxicity surveillance should be improved, and regulations of energy-drink sales and consumption should be based on appropriate research.

 

[Michael Scally MD]

Given what I thought was the common thought that marijuana was additive to sex health, these conclusions came as a surprise. Is the mechanism of action similar to alcohol?

Cannabis (marijuana) is the most widely used illicit drug globally. In 2004, the United Nations Office on Drugs and Crime (UNODC) estimated that approximately 4% of the world’s adult population (162 million people) use cannabis annually, with 0.6% (22.5 million) reporting daily use. The possession, use, or sale of cannabis preparations containing psychoactive cannabinoids (CBs) was deemed illegal in most parts of the world in the early 20th century. Cannabis may confer multiple deleterious effects upon normal physiology, the most common of which is the central nervous system. Tetrahydrocannabinol, the active metabolite, may serve as a central nervous system stimulant, depressant, and/or a hallucinogen.

Erectile dysfunction (ED) is the inability to attain or maintain penile erection sufficient enough for sexual intercourse. It is one of the most common worldwide male sexual disorders which is projected to affect 322 million men in 2025. Causes of ED may be psychological, organic, or most commonly a mix of both. Given the prevalence of nonprescription illicit drug abuse, there is a growing interest in the study of its potential effects on male sexual health. In this review, researchers discuss the effects of cannabis on male sexual health.


Shamloul R, Bella AJ. Impact of Cannabis Use on Male Sexual Health. The Journal of Sexual Medicine. Impact of Cannabis Use on Male Sexual Health - Shamloul - 2011 - The Journal of Sexual Medicine - Wiley Online Library

Objective. In this review, we discuss the effects of cannabis on male sexual health.

Methods and Main Outcome Measure. Critical review of scientific literature examining the impact of cannabis use on male sexual health.

Results. Studies examining the effects of cannabis use on male sexual function have been limited in both quality and quantity. Most results of these studies are conflicting and contradictory. While some did outline the beneficial effects of cannabis in enhancing erectile function, others did not. However, recent animal and in vitro studies have identified potential links between cannabis and sexual health. It appears that cannabis may actually have peripheral antagonizing effects on erectile function by stimulating specific receptors in the cavernous tissue.

Conclusions. Given the prevalence of cannabis use, and the potential relationships between use and the development of potentially hazardous effects on male sexual function, we encourage renewed use of research resources to determine in-depth mechanistic knowledge, and new clinically oriented studies examining the effect of cannabis on male sexual function.

 

[Michael Scally MD]

Early Baldness May Have Link to Prostate Cancer
Medical News: Early Baldness May Have Link to Prostate Cancer - in Oncology/Hematology, Prostate Cancer from MedPage Today

Men who start to lose their hair at age 20 may be more likely to develop prostate cancer later in life, a case control study suggested.

The study, involving 388 men with a history of prostate cancer and 281 without, found that those with prostate cancer were twice as likely to have early balding compared with healthy controls, reported Philippe Giraud, MD, PhD, of the Hôpital Européen Georges Pompidou in Paris, and colleagues.

However, the study found no link between hair loss at age 20 and early diagnosis of prostate cancer or tumor aggressiveness, Giraud and co-authors reported online in the Annals of Oncology.

Noting that there's currently no evidence of benefit for general screening for prostate cancer, the investigators suggested that their finding may help identify a subgroup of men who would benefit both from screening and possible early treatment.

"We need a way of identifying those men who are at high risk of developing the disease and who could be targeted for screening and also considered for chemoprevention using anti-androgenic drugs such as finasteride," Giraud said in a statement.

"Balding at the age of 20 may be one of these easily identifiable risk factors and more work needs to be done now to confirm this," he added.

Male pattern baldness -- or androgenic alopecia -- affects about half of all men at some time during their lives and the condition has been linked with androgenic hormones, which also play a role in the development and growth of prostate cancer.

The drug finasteride, which blocks the conversion of testosterone to dihydrotestosterone, is sold as Proscar to treat benign prostatic hyperplasia and as Propecia to treat baldness.

The study, begun in September 2004, involved a questionnaire administered to consecutive prostate cancer patients seen in three French radiation oncology units; questions included personal and family prostate cancer history.

The men were also asked to identify their balding pattern at age 20, using a set of pictures showing four stages of hair loss -- no balding (or stage I), a receding hairline around the temples (stage II), a round bald patch at the top of the head (stage III), or a combination of both types of hair loss (stage IV).

Controls were age-matched patients in the same institutions without prostate cancer.

All told, Giraud and colleagues enrolled 388 prostate cancer patients (88% of those who were asked) and 281 healthy controls (76% of those invited to take part).

All of the participants' physicians were asked to confirm the presence or absence of prostate cancer, and to give clinical details, including such things as age at diagnosis, initial cancer staging, and treatment.

Analysis of the cohort showed:

37 cases and 14 controls reported any balding -- stages II through IV -- at age 20, yielding an odds ratio of 2.01, which was significant at P=0.03.

There was no significant association between prostate cancer and balding at either 30 or 40.

The type of balding was not associated with prostate cancer, although there were only three respondents who reported stage III balding at age 20 and none who reported stage IV.

The average age at cancer diagnosis of patients with no balding by 40 was 64.3 years, while those with any balding by 20 and 40 had a mean age of diagnosis of 64.4 and 64.5, respectively.

Early balding was also not associated with tumor stage, Gleason score, or level of prostate specific antigen.

The researchers cautioned that the study asked patients to remember balding patterns that had occurred some decades earlier -- which may have led to recall bias.

On the other hand, Giraud and colleagues commented, since hair loss affects self-image, most men with early balding would probably remember it clearly.

The researchers also did not control for other prostate cancer risk factors, "such as African heritage or dietary differences," but added that having a family history of prostate cancer was comparable in cases and controls


Yassa M, Saliou M, De Rycke Y, et al. Male pattern baldness and the risk of prostate cancer. Annals of Oncology. Male pattern baldness and the risk of prostate cancer — Ann Oncol

Background: Androgens play a role in the development of both androgenic alopecia, commonly known as male pattern baldness, and prostate cancer. We set out to study if early-onset androgenic alopecia was associated with an increased risk of prostate cancer later in life.

Patients and methods: A total of 669 subjects (388 with a history of prostate cancer and 281 without) were enrolled in this study. All subjects were asked to score their balding pattern at ages 20, 30 and 40. Statistical comparison was subsequently done between both groups of patients.

Results: Our study revealed that patients with prostate cancer were twice as likely to have androgenic alopecia at age 20 [odds ratio (OR) 2.01, P?=?0.0285]. The pattern of hair loss was not a predictive factor for the development of cancer. There was no association between early-onset alopecia and an earlier diagnosis of prostate cancer or with the development of more aggressive tumors.

Conclusions: This study shows an association between early-onset androgenic alopecia and the development of prostate cancer. Whether this population can benefit from routine prostate cancer screening or systematic use of 5-alpha reductase inhibitors as primary prevention remains to be determined.