Testosterone and obesity in men under the age of 40 years.

The study assessed anthropometric and laboratory variables, in particular testosterone (T) in a group of obese men of <40 years. Of 60 men with a body mass index (BMI) of >27 kg m(-2), 34 met the criteria of the metabolic syndrome (MS). Twenty men <40 years (with a BMI <25 kg m(-2)) were studied for comparison. It was found that with increasing BMI, levels of serum leptin, triglycerides, insulin, the ratio high-density lipoprotein (HDL) cholesterol/low-density liporotein (LDL) cholesterol, the waist circumference (WC), the area of visceral fat and systolic/diastolic blood pressure were higher, whereas insulin sensitivity (HOMA) and serum T were lower. Obesity (BMI 27-30 kg m(-2)) was associated with a decline in plasma T, but not with a decline in plasma sex hormone-binding globulin (SHBG). The latter was the case in more severe obesity (>30 kg m(-2)) qualifying as MS. In patients with MS, 58% variability of T levels could be predicted by combination of independent factors - SHBG, ratio LDL/HDL, insulin and leptin. On the other hand, in men with MS, 80% variance of concentrations of SHBG were predicted by triglycerides, HDL, glucose, leptin and surface of visceral adipose tissue. It is concluded that plasma T is significantly correlated with a number of features of the MS and, therefore, plasma T could serve as a marker of the MS.