[OA] Cardiovascular and Cerebrovascular Safety of Testosterone Therapy
To the Editor:
We read with great interest the study by Loo et al1 concerning testosterone (T) therapy increasing the risk of cerebral and cardiovascular disease.
Cardiovascular and Cerebrovascular Safety of Testosterone Replacement Therapy Among Aging Men with Low Testosterone Levels: A Cohort Study - ScienceDirect
Unfortunately, the authors’ conclusions are not supported by the results, raising serious concerns. Here we highlight some of these concerns:
1. The single most important finding of this study is that almost twice as many men in the untreated group DIED vs the treatment group, in agreement with previous studies. If we were to counsel a symptomatic hypogonadal patient based on this study and the results of the T trials, we would advise him that T therapy will improve sexual function, walking distance, mood, bone mineral density, anemia, lean muscle mass, insulin sensitivity, and significantly increase his chances of being alive in 5-10 years’ time.
A major critical confounder, inadequately recognized by authors, is that T deficiency itself is a risk for increased cardiovascular events. For this reason, some investigators have elected to censor major adverse cardiovascular events during the first 12 months because those events may be related to the underlying condition rather than T treatment. Failing to take measures like this may account for differences in results between studies. Considerable published data contradict the findings of this study.
2. A careful look at the crude hazard ratios reported in Tables 2-4 suggests that there were no significant statistical differences between the treated and nontreated groups, except in Table 4, where all-cause mortality was significantly reduced in the treated group when compared with both the nontreated group and the “past use” group. The absence of statistically significant results was surprising, because the sample sizes are quite large.
Examining the forest plot, it is clear that there is a lot of variability in the estimates, and even with the large sample size, the authors did not claim any significant differences and most importantly, if these differences are clinically important. There appears to be a lack of evidence of probable clinical significance.
3. It is disturbing that the authors had a preconceived view that only men with classical hypogonadism should be treated, yet they present no evidence as to how results from a “classical” cohort would have been different from those men with nonclassical hypogonadism. On the contrary, the benefits from the T trial were seen in men with “functional” hypogonadism.
4. The authors dismissed symptoms of hypogonadism as due to “aging” and suggested that these symptoms should be tolerated, even for men in their 50s. If this were the case, then hypertension, cataracts, retinal degeneration, and hearing loss should be left untreated and accepted as a consequence of aging.
In addition, the inclusion of a comparative cohort taking 5α-reductase inhibitors is completely irrelevant and bears no basis for comparison. The authors appeared to have preconceived views and seem determined to ensure that their findings are interpreted to fit these views.
Traish AM, Hackett G, Miner M, Morgentaler A. Cardiovascular and Cerebrovascular Safety of Testosterone Therapy. Am J Med 2019. https://www.amjmed.com/article/S0002-9343(19)30433-4/fulltext