Men with type 2 diabetes and cardiovascular risk focus of study.
Though there is an abundance of preclinical and observational data on testosterone, there are uncertainties when it comes to testosterone’s effect on the cardiovascular system. There has not been a randomized controlled clinical trial adequately powered to study the effects of testosterone on cardiovascular outcomes. There have been meta-analyses of existing testosterone studies, but they proved to be inconclusive. Cardiovascular events are the number-one leading cause of death in men and are especially prevalent in patients with type 2 diabetes. The use of testosterone therapy in men has been rising; therefore, it is important to see if there is an association between testosterone and cardiovascular events.
Testosterone is a natural hormone produced by the body. It is responsible for many of the body’s functions like helping to build muscles, deepening the voice, and boosting the size of the male genitals during puberty. In adults, testosterone maintains the muscles and bones as well as sexual drive. Men will begin to experience a decline in testosterone usually after the age of 30. Low testosterone has been associated with obesity. Epidemiological studies support the relationship between testosterone and obesity, which leads to metabolic syndrome.The study also finds that low total testosterone is associated with type 2 diabetes independent of age, race, obesity, and criteria for diagnosis of diabetes. Because diabetes is associated with obesity, which suppresses testosterone levels, this brings into question the role of testosterone’s effects on diabetes. Cardiovascular complication is highly associated with patients with diabetes, thus, studies that are focused on testosterone’s effects on the heart are needed.
When a cardiovascular event occurs, there are several cardiac biomarkers such as troponin and brain natriuretic peptides that have been found to be associated with subclinical cardiac injury in asymptomatic patients. By looking at these biomarkers, providers can assess cardiac risk. Two biomarkers of interest in this study are N-terminal pro B-type natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin T (hs-cTnT), which could improve the assessment of cardiovascular risk in patients with diabetes. NT-proBNPs are peptides that are secreted by the myocardium as a response to volume expansion.Troponin are specific markers of cardiac damage released when there is cardiac injury. These two markers are good indicators of cardiac health.
This is a randomized double-blind, parallel, placebo-controlled trial that looked at men aged 35 to 70 with type 2 diabetes and total testosterone level below 12.0 mmol/L. Participants in the study also have to be at high risk for cardiovascular disease with the median 10-year United Kingdom Prospective Diabetes Study (UKPDS) coronary heart disease (CHD) risk at 21%. The study recruited 88 participants who were randomly assigned to receive 40 weeks of intramuscular testosterone undecanoate (n=45) or matching placebo (n=43). The study data showed that those treated with testosterone showed a reduction in NT-proBNP) over the course of 40 weeks compared to the placebo group. However, the study did not find a reduction in hs-cTnT levels in either group. Unfortunately, the study could not find significant association between testosterone use and cardiac biomarkers.
In conclusion, the study found that testosterone lowered NT-proBNP, but did not affect hs-cTnT. Even though the study could not find an association between cardiovascular events and testosterone, further studies should evaluate cardiovascular biomarkers and testosterone-associated cardiovascular events.
- Low testosterone is associated with obesity.
- As adults, testosterone maintains muscle, bones and sexual drive.
- The study could not find any association between testosterone and cardiovascular events.
Researched and prepared by Javeria Fayyaz, Doctor of Pharmacy Candidate LECOM of Pharmacy, reviewed by Dave Joffe, BSPharm, CDE
Gianatti EJ, et al. “ Effect of testosterone treatment on cardiac biomarkers in a randomized controlled trial of men with type 2 diabetes.” Clin Endocrinol (Oxf). 2016 Jan;84(1):55-62.
Wang, Christina, et al. “Low testosterone associated with obesity and the metabolic syndrome contributes to sexual dysfunction and cardiovascular disease risk in men with type 2 diabetes.” Diabetes care 34.7 (2011): 1669-1675.