Men with abnormally low or high testosterone levels face an increased risk of developing atrial fibrillation, a study published in the Journal of the Endocrine Society found.
Researchers analyzed existing studies examining testosterone concentrations, hormone replacement therapy, and cardiovascular health. They identified a distinct U-shaped pattern in the data, showing that the likelihood of experiencing irregular heart rhythms was highest at both low and high hormone concentrations, while remaining lowest near the middle of the normal reference range.
Based on the observational findings, the study authors suggested that men requiring testosterone replacement therapy should not aim for the upper limit of the normal range. Instead, researchers recommended maintaining testosterone levels between 350 and 550 nanograms per deciliter alongside regular monitoring of the cardiovascular system.
Understanding Atrial Fibrillation
Atrial fibrillation is a widespread heart rhythm disorder characterized by irregular and frequently rapid beating of the heart's upper chambers. The condition alters normal blood circulation through the cardiovascular system, which can cause blood to pool and form dangerous blood clots. Over time, untreated irregular heart rhythms can lead to serious complications including stroke and heart failure.
Testosterone is the primary androgenic hormone in men, produced mainly in the testicles. It regulates vital physiological processes throughout life, including muscle mass, bone density, fat distribution, and red blood cell production. As men age, natural hormone production often decreases. Those diagnosed with clinical hypogonadism or low testosterone levels may be prescribed testosterone replacement therapy in the form of gels, patches, or injections to restore hormonal balance.
Biological Impact on Cardiac Cells
The authors suggested that hormone deficiency and hormone excess may influence heart cells through different biological mechanisms. This variation in cellular impact could explain why both high and low testosterone levels contribute to cardiac arrhythmia risk.
Researchers emphasized that the proposed target range of 350 to 550 nanograms per deciliter is based predominantly on observational data. They noted that the range has not yet been tested or verified in dedicated clinical trials.
Context and Medical Research
The Journal of the Endocrine Society is an open-access, peer-reviewed medical journal published by the Endocrine Society. The publication highlights scientific research and clinical investigations focused on endocrinology, hormonal pathways, and metabolic health.
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