Endocrine Abstracts

BACKGROUND: Previous work has demonstrated a relationship between impaired carbohydrate metabolism and low serum levels of androgens in men. Men with diabetes have lower testosterone levels, and administration of physiological doses of testosterone improves glucose tolerance in these men. Men with coronary artery disease (CAD) have lower androgen levels than men with normal coronary arteries. We studied the relationship between testosterone, glucose, hypertension and DM in a population of men with CAD.

METHODS: 500 men with CAD ( >70% stenosis in one or more coronary artery at angiography) were studied. Blood was collected between 7 and 10 am and total and bioavailable testosterone (TT and BT), SHBG and glucose (random) were measured. Body mass index (BMI) and history of hypertension were recorded. Hypogonadism was defined as TT <7.6nM and\/or BT <2.6nM. Data were analysed using Pearson's correlation, Chi-square and Student's t tests and are presented as mean(SD).

RESULTS: Mean age was 61.2(8.9)yrs, BMI; 27.9(4.0)kg/m2. Men with diabetes (n=70, BMI; 29.5(4.7)kg/m2) had a lower circulating TT (12.7(5.2)nM v 15.0(6.5)nM, p<0.05) and SHBG (40.1(24.6)mM v 47.3(26.1)mM, p<0.05) than those without diabetes. Plasma TT (but not BT) and SHBG showed inverse relationship with blood glucose (r=-0.1, p<0.05 & r-0.2, p<0.05). There was a significant negative correlation between both TT and BT with BMI (r=-0.2, p<0.001). A high proportion of diabetics were hypogonadal (30%, p<0.01) and similarly, hypogonadal men were more likely to be diabetic (22%, p<0.01). There were no statistical differences in mean hormone levels between hypertensive and non-hypertensive populations.

DISCUSSION: These findings show that relative androgen deficiency is associated with impaired carbohydrate metabolism, although, whether this represents cause or effect remains unclear. We have demonstrated a high prevalence of hypogonadism in men with diabetes and CAD.