The differences between aromatizable and non-aromatizable androgens in relation to body composition and metabolic syndrome risk factors in men

The relationships between the parameters of metabolic syndrome and non-aromatizable metabolites of testosterone have been discussed in literature. Some papers describe these metabolites as one of the possible causes of male-type obesity. On the contrary, other studies show a protective influence of dihydrotestosterone on visceral obesity. The aim of this study to analyse the relationship between anthropometric parameters, lipid spectrum, glycemia and the level of endogenous testosterone and dihydrotestosterone, and to compare the effects of these androgens. Our population-based study involved 232 healthy men ranging from 20 to 78 years with BMI 18 to 39 kg/m(2). Serum testosterone, dihydrotestosterone and sex hormone binding globulin SHBG levels, lipid spectrum, glucose metabolism parameters were measured and the oral glucose tolerance test was carried out in all subjects. Their anthropometric parameters (weight, height, waist, hips, waist-to-hip ratio, 14 skin folds) and body composition parameters were determined and calculated by the Antropo program. Multiple regression analysis showed a correlation between hormonal levels, esp. of testosterone and dihydrotestosterone, and the anthropometric data, lipid spectrum and parameters of glucose regulation. Low testosterone and/or dihydrotestosterone was correlated to a higher body-mass index, fat content, waist diameter, total-, HDL-, LDL-cholesterol and triglycerides, fasting glucose, insulin resistance and lower muscle and bone mass. In addition, statistical analysis using multivariate regression with reduction in dimensionality did not discover any striking difference between aromatizable and non-aromatizable androgens in their association to lipid and glucose metabolism parameters in healthy, normosthenic men. In conclusion, the association of endogenous testosterone and dihydrotestosterone to anthropometric data, lipid spectrum and insulin sensitivity are of the same quality; however, the effect of the circulating levels of dihydrotestosterone is quantitatively smaller.