HANGZHOU, CHINA. In May 2002 Italian researchers reported that blood levels of dehydroepiandrosterone (DHEA) are significantly lower in men with atrial fibrillation (AF) than in afib-free controls. DHEA is an important precursor of many hormones including testosterone. Now a group of Chinese cardiologists has discovered that men with lone atrial fibrillation tend to have lower testosterone levels than do men free of afib.

Their study involved 58 men who had been diagnosed with paroxysmal (96.6%) or permanent (3.4%) lone afib. The average age at first diagnosis was 39 years and age at enrolment in the study was 46 years. All the men had structurally normal hearts and were not hypertensive or overweight. Average left ventricular ejection fraction was excellent at 71% and average left atrial diameter was 37.5 mm. Blood samples were drawn from the 58 men and from a control group of 58 healthy, male outpatients and levels of testosterone and estradiol compared.

The lone afibbers were found to have a significantly lower level of testosterone (476 ng/dL) than did members of the control group (514 ng/dL). There was no significant difference in estradiol levels (31.9 pg/mL vs. 32.4 pg/mL). The Chinese researchers conclude that men with low testosterone levels may have a greater susceptibility to developing lone AF. They also point out that the increased release of atrial natriuretic peptide (ANP) resulting from cardiac overload is reduced by testosterone.

Lai, J, et al. Reduced testosterone levels in males with lone atrial fibrillation. Clinical Cardiology, Vol. 32, 2009, pp. 43-46

Editor�s comment: Could supplementation with DHEA or testosterone be beneficial for lone afibbers? As far as I know, no research has been carried out in this area. However, men with prostate problems, including cancer, should not supplement with DHEA or testosterone without very close medical supervision since doing so may further aggravate benign prostatic hyperplasia (BNP) and cancer as both rely heavily on testosterone and its metabolite, dihydrotestosterone, to fuel cell growth.