Research links testosterone therapy and increased cardiac risk factors and hypertension.
Testosterone therapy is a treatment used for men whose testes do not produce enough testosterone ― the main male sex hormone. This may be due to absence, injury, or disease. Several clinical trials and analyses have shown that this therapy improves several cardiac risk factors with none having found adverse cardiovascular outcomes. However, most of the studies have been small, enrolled patients of different ages, and were of variable duration.
Basically there has been no clinical trial assessing the effect of testosterone therapy on cardiovascular outcomes including mortality, MI, and stroke of which high blood pressure is a major contributor.
This prompted a group of researchers to study the topic. Their results are completely different from prior studies and suggest that “testosterone treatments may increase risks for heart attacks, strokes and death in older men with low hormone levels and other health problems.” Their findings raise some uncertainty regarding the potential safety of testosterone use. The researchers suggest that “although physicians should continue to discuss the symptomatic benefits of testosterone therapy with patients, it is also important to inform patients that long-term risks are unknown and there is a possibility that testosterone therapy might be harmful.”
The nationwide study, published in the latest Journal of the American Medical Association, involved an analysis of health data on 8,700 veterans with low levels of testosterone. All had undergone a heart imaging test and many had risk factors for heart problems, including blocked heart arteries. Risks linked with testosterone were similar in men with and without existing heart problems.
Nearly 26 percent of men using testosterone had one of the bad outcomes within three years of the heart test, compared with 20 percent of nonusers. While it is unclear how the hormone might increase heart risks, the study authors suggest that testosterone might make blood substances called platelets stick together, which could lead to blood clots.
Testosterone administration has also been shown to worsen sleep disordered breathing among patients with severe obstructive sleep apnea, which is a risk factor for atherosclerosis. There is a large body of research showing that people with sleep apnea are also at risk of developing hypertension.
Clearly there are several potential mechanisms by which testosterone therapy could increase risk of adverse cardiovascular outcomes. The researchers recommend further study of these mechanisms to help inform whether long-term testosterone therapy use is safe or if it is associated with adverse cardiovascular events.