Physical Activity & Morbidity/Mortality

[Michael Scally MD]

25-Year Physical Activity Trajectories and Development of Subclinical Coronary Artery Disease as Measured by Coronary Artery Calcium

Objective - To evaluate 25-year physical activity (PA) trajectories from young to middle age and assess associations with the prevalence of coronary artery calcification (CAC).

Patients and Methods - This study includes 3175 participants in the Coronary Artery Risk Development in Young Adults (CARDIA) study who self-reported PA by questionnaire at 8 follow-up examinations over 25 years (from March 1985-June 1986 through June 2010-May 2011). The presence of CAC (CAC>0) at year 25 was measured using computed tomography. Group-based trajectory modeling was used to identify PA trajectories with increasing age.

Results - We identified 3 distinct PA trajectories:
trajectory 1, below PA guidelines (n=1813; 57.1%);
trajectory 2, meeting PA guidelines (n=1094; 34.5%); and
trajectory 3, 3 times PA guidelines (n=268; 8.4%).

Trajectory 3 participants had higher adjusted odds of CAC>0 (adjusted odds ratio [OR], 1.27; 95% CI, 0.95-1.70) vs those in trajectory 1.

Stratification by race showed that white participants who engaged in PA 3 times the guidelines had higher odds of developing CAC>0 (OR, 1.80; 95% CI, 1.21-2.67). Further stratification by sex showed higher odds for white males (OR, 1.86; 95% CI, 1.16-2.98), and similar but nonsignificant trends were noted for white females (OR, 1.71; 95% CI, 0.79-3.71). However, no such higher odds of CAC>0 for trajectory 3 were observed for black participants.

Conclusion - White individuals who participated in 3 times the recommended PA guidelines over 25 years had higher odds of developing coronary subclinical atherosclerosis by middle age. These findings warrant further exploration, especially by race, into possible biological mechanisms for CAC risk at very high levels of PA.

Laddu DR, Rana JS, Murillo R, et al. 25-Year Physical Activity Trajectories and Development of Subclinical Coronary Artery Disease as Measured by Coronary Artery Calcium: The Coronary Artery Risk Development in Young Adults (CARDIA) Study. Mayo Clinic Proceedings 2017;92(11):1660-70. http://www.mayoclinicproceedings.org/article/S0025-6196(17)30577-3/fulltext

 

[Michael Scally MD]

Effect of Moderate to Vigorous Physical Activity on All-Cause Mortality

Importance Few studies have examined how different proportions of moderate and vigorous physical activity affect health outcomes.

Objective To examine whether the proportion of total moderate to vigorous activity (MVPA) that is achieved through vigorous activity is associated with all-cause mortality independently of the total amount of MVPA.

Design, Setting, and Participants We performed a prospective cohort study with activity data linked to all-cause mortality data from February 1, 2006, through June 15, 2014, in 204 542 adults aged 45 through 75 years from the 45 and Up population-based cohort study from New South Wales, Australia (mean [SD] follow-up, 6.52 [1.23] years). Associations between different contributions of vigorous activity to total MVPA and mortality were examined using Cox proportional hazards models, adjusted for total MVPA and sociodemographic and health covariates.

Exposures Different proportions of total MVPA as vigorous activity. Physical activity was measured with the Active Australia Survey.

Main Outcomes and Measures All-cause mortality during the follow-up period.

Results During 1 444 927 person-years of follow-up, 7435 deaths were registered. Compared with those who reported no MVPA (crude death rate, 8.34%), the adjusted hazard ratios for all-cause mortality were 0.66 (95% CI, 0.61-0.71; crude death rate, 4.81%), 0.53 (95% CI, 0.48-0.57; crude death rate, 3.17%), and 0.46 (95% CI, 0.43-0.49; crude death rate, 2.64%) for reporting 10 through 149, 150 through 299, and 300 min/wk or more of activity, respectively. Among those who reported any MVPA, the proportion of vigorous activity revealed an inverse dose-response relationship with all-cause mortality: compared with those reporting no vigorous activity (crude death rate, 3.84%) the fully adjusted hazard ratio was 0.91 (95% CI, 0.84-0.98; crude death rate, 2.35%) in those who reported some vigorous activity (but <30% of total activity) and 0.87 (95% CI, 0.81-0.93; crude death rate, 2.08%) among those who reported 30% or more of activity as vigorous. These associations were consistent in men and women, across categories of body mass index and volume of MVPA, and in those with and without existing cardiovascular disease or diabetes mellitus.

Conclusions and Relevance Among people reporting any activity, there was an inverse dose-response relationship between proportion of vigorous activity and mortality. Our findings suggest that vigorous activities should be endorsed in clinical and public health activity guidelines to maximize the population benefits of physical activity.

[OA] Gebel K, Ding D, Chey T, Stamatakis E, Brown WJ, Bauman AE. Effect of Moderate to Vigorous Physical Activity on All-Cause Mortality in Middle-aged and Older Australians. JAMA Intern Med. 2015;175(6):970–977. Physical Activity and Mortality

 

[TheOldFart]

So do I understand this correctly - young guys should sit on the couch and us older guys should exercise like hell? Am I missing something?

 

[Old]

So do I understand this correctly - young guys should sit on the couch and us older guys should exercise like hell? Am I missing something?

As a guideline, when exercising, stop once cortisol starts to rise. If exercise causes muscle loss, then it is too much. Cortisol is useful to quick action. Continual elevated levels of cortisol damage vascular (heart and brain), bones and joints, causes cataracts and neurological injury, and insulin-resistance/diabetes.
Exercise should build muscle and balance. Endurance is tricky.