[Leptin in persons with simple obesity].

Obesity is a disease with distinct genetic determination and its phenotype is defined by the still unknown number of genes whose expression can be influenced by environmental factors. Several years ago, "obesity gene" was isolated in animals. This gene, coding protein which consists of 165 amino acids, is called leptin. Leptin is supposed to be a key substance controlling homeostasis of body weight and energy balance; it is produced by adipocytes and its value correlates highly significantly with anthropometric parameters that characterize physical constitution and amount of subcutaneous fatty tissue. The obese individuals often display hyperleptinemia which is frequently caused by a postreceptor disorder; sporadically, a different leptin structure or hypoleptinemia (caused by genetic anomaly) are reported. It is supposed that either absolute or relative leptin deficiency in obese persons are associated with causal obesity (e.g. appetite stimulation). Leptinemia values correlate with percentage of subcutaneous fatty tissue, insulinemia and sometimes with glycemia. In our study we examined 200 probands, patients of the Metabolic and Diabetologic Out-Patient Department, Hospital in Sternberk. A very close correlation between the amount of subcutaneous fatty tissue (measured by a caliper in 10 skinfolds) and the leptine serum concentration was found. The values of leptinemia in men of normal constitution ranged within 1-11 ng/ml, non-obese women had 3-4 times higher values. Leptinemia in some obese individuals reached up to 70 ng/ml. However, the currently calculated and reported parameters of physical constitution (BMI, WHR, Grant index) did not correlate significantly with leptinemia. Similarly, biochemical parameters considered as general markers of insulin resistance (often associated with obesity) did not correlate significantly with leptinemia. This finding indicates that some calculated parameters, quantifying and gualifying physical constitution, may be ambiguous and leptinemia was found to give more detailed information about the amount of subcutaneous fatty tissue than WHR or BMI. An accidental finding was an important positive correlation between myoglobin concentration and creatinemia. At monitoring the effect of hypolipidemic agents we use the myoglobin examination and therefore we consider this correlation to be very important and every physician performing this analysis should be informed about it. The present study thus confirmed that a more accurate quantification of subcutaneous fatty tissue is required. On the other hand, we believe that examination of leptinemia can contribute significantly to stratification of patients into risk groups (with respect to clinical, economic and time differentiation) and subsequently to the treatment of these patients. In future, criteria for quantification of leptinemia and leptine resistance should be defined precisely.