[Metabolic effects of obesity in men]

Obesity is a product of welfare. About 1/3 of our population has got excessive weight, 6 to 8% is truly obese and in 0.1% we may speak of pathologic obesity. Obesity is not only an esthetic problem, but is goes together with higher morbidity and mortality. In men with a body mass index (BMI = W (kg)/L2 (m)) of more than 35, the glucose metabolism was disturbed in 70%, the lipid spectrum had a clearly atherogenic profile, the average (free) testosterone level was significantly diminished and there was also a certain degree of hypogonadism. A short term treatment (4 to 6 weeks) based on a hypocaloric diet (400) and rich in proteins normalized the glucose metabolism in a very great number of patients, while the insulinemia fell with 40% and the lipidogram always became normal, but for the HDL-C, which showed a slight drop, while the testosterone levels became normal with a strong rise of the sex hormone binding globulin. And yet, at that very moment the patients were still definitely obese: this suggests that the metabolic disturbances are not the consequence of obesity in itself, but may be related to the dietary habits of the patients. Concerning the mechanism of hypogonadism, the cause of its disturbance seems to be situated in the hypothalamo-hypophyseal area and be characterized by a lower amplitude of LH-pulses, which are correlated with the testosterone levels. This hypothalamic disorder is however not limited to the LH-secretion, but the amplitude of growth hormone- and of ACTH-pulses is also reduced. Our study suggests that not obesity itself, but dietary factors might be responsible for the detected abnormalities. This might have important implications. Indeed, it is well known that in population groups, whose diet contains fewer calories and less fat--such as the Chinese and the Japanese--sex hormone binding globulin exists in far higher concentrations whereas free testosterone is found in a lower concentration. In these populations the prevalence of clinically obvious prostate cancer--which is androgen-sensitive--is much lower than in Western countries: it seems obvious to look for a correlation between both observations. Another remarkable phenomenon is the difference in testosterone metabolism between the Eastern and Western people; this leads us to the remarkable findings that in Asian people the same amount of androgens nearly always produces azoospermia and infertility, whereas this appears in only 2/3 of the cases among Western people.(ABSTRACT TRUNCATED AT 400 WORDS)