Of considerable interest is the relationship between testosterone blood levels and cardiovascular events such as heart attack and stroke. In a revealing new study, researchers identified 2,416 men (aged 69-81 years) who were not on any kind of testosterone- affecting treatment. These men were subjected to a battery of blood tests that included total testosterone and estradiol (estrogen).
The first observation was that men with increasing levels of testosterone had a decreased prevalence of diabetes, hypertension, and body fat mass. Compared to men with the highest testosterone levels, those with low testosterone were twice as likely to have a history of cardiovascular disease. It was also observed that men with the highest testosterone levels were the most physically active.17
This large group of men was followed for an average of 5.1 years. Men in the highest quartile of total testosterone (above 550 ng/dL) had a 30% lower risk of cardiovascular events. Any level of total testosterone below 550 ng/dL resulted in significant increased risk, thus helping to establish a minimal baseline as to where total testosterone should be to guard against heart attack or stroke.
Estradiol levels measured in this group appeared to be mostly in safe ranges and did not impact incidence of cardiovascular events.