A systematic review and meta-analysis found that low baseline serum (endogenous) testosterone concentration in men is associated with an increased risk of all-cause mortality, and a very low baseline testosterone level is associated with an increased risk of cardiovascular death. According to the authors, this study clarifies previous inconsistent findings on the influence of sex hormones on important health outcomes in aging men. The findings are published in Annals of Internal Medicine.
Researchers from the University of Western Australia, in collaboration with researchers from Australia, Europe, and North America, reviewed 11 studies involving more than 24,000 participants to clarify the relationship between sex hormones and mortality and the risk of cardiovascular disease (CVD) in aging men. Eligible studies were prospective cohort studies previously identified in a published systematic review, in community-dwelling men with total testosterone concentrations measured by mass spectrometry and a follow-up period of at least 5 years. Individual patient data (IPD) were used to summarize relationships between baseline hormone concentrations (total testosterone, sex hormone-binding globulin, luteinizing hormone, dihydrotestosterone, and estradiol) and the relative risk of CVD events, CVD deaths, and all-cause mortality. The data showed that only men with low total testosterone concentrations had a higher risk of all-cause mortality. An important finding was that men with a testosterone concentration below 7.4 nmol/L (<213 ng/dL) had a higher risk of all-cause mortality, regardless of LH concentration. Men with a testosterone concentration below 5.3 nmol/L (<153 mg/dL) had an increased risk of cardiovascular death.
The author of an accompanying editorial from the University of Washington points out that this meta-analysis is particularly valuable due to its rigorous methodology. The study is the first of its kind to perform an IPD meta-analysis of large prospective cohort studies that uses mass spectrometry, the most accurate method for testosterone measurement, which can also be used to accurately measure DHT and estradiol. To perform the IPD meta-analysis, the authors also obtained raw data from nine of the included studies and subsequently re-analyzed the combined data.
https://www.acpjournals.org/doi/10.7326/M23-2781
