Only a few low-quality studies show adverse effects of testosterone therapy on the brain and heart
The number of studies that show adverse cardiovascular effects of testosterone therapy is very small in comparison with the much greater number of studies showing protective effects: 5 “negative” studies (including one study that shows a mixture of beneficial and adverse effects on coronary arteries) compared to 17 studies showing neutral effects (no adverse effects) and 58 published trials that show cardio- and cerebrovascular protection of testosterone therapy. Furthermore, in approximately 100 studies, high testosterone levels are associated with cardiovascular protection, whereas it is difficult to find a single study showing the opposite. Moreover, it is worth noticing that the studies that show cardiovascular adverse effects of testosterone therapy present important biases and quality errors that make them less trustable.
Excessive conversion of testosterone to estradiol may be the explanation behind the unexpected unfavorable results
There might be some truth behind the unexpected adverse effects of testosterone found in the five studies. During testosterone therapy some of the testosterone converts into the female hormone estradiol. In some men, excessive amounts of testosterone can convert to estradiol. Men with high estradiol levels tend to develop significantly more atherosclerosis, coronary heart disease, arterial hypertension, and stroke. When estradiol levels become excessive, the estradiol tends to block testosterone receptors, blocking as a result the protective effect of testosterone on the cardiovascular system. If this is the real explanation for why testosterone therapy may cause cardio and cerebrovascular problems in some men, then all studies that examine the effect of testosterone therapy on men should include a measurement of the serum estradiol levels. In fact, because of the risks presented by high estradiol levels in men, the follow-up of any testosterone treatment should include regular measurements of estradiol next to that of testosterone and the other important tests related to testosterone.
To access the relevant data on testosterone deficiency, testosterone therapy, and their association with cardiovascular disease on the International Hormone Society website, in the Evidence-based hormone therapies section (available soon).
To get more references and practical information on testosterone therapy, read my 600-page book for physicians, “Testosterone, the Therapy for Real Gentlemen”.
To get practical and in-depth training on testosterone therapy and come attend the hormone therapy workshop in Orlando on August 21-22, 2020. Check out the Evidence-based hormone therapy workshop here, which will be available at the A4M 28th Annual Spring Congress being held in Orlando, Florida on August 20-22, 2020.
