Abstract

Physical activity induces changes in endocrine system. Previous data indicated that very important for energy metabolism are changes in insulin secretion and tissue response for this hormone. It is believed that they are accompanied by changes in lipid metabolism, but factors contributing in this process are still disputed. The aim of this study was to assess interactions among insulin sensitivity, thyroid function, bone turnover marker and serum lipid profile in young physically active men. Eighty-seven physical education students, aged 18-23 y participated in the study. We measured serum levels of glucose, lipids, insulin, TSH, osteocalcin and anthropometric parameters. Insulin sensitivity was determined using homeostatic model assessment for insulin resistance (HOMA-IR). The median value of HOMA-IR (1.344) was used to divide study population into Group A (above the median) and Group B (below the median). Men from both groups did not differ in anthropometric parameters and also in daily physical activity. TG, TC and HDL-C levels were higher in Group A (P<0.05). TSH and osteocalcin levels were similar in males with different HOMA-IR. Multiple regression analysis for TSH and osteocalcin showed that in Group A these hormones had no effect on plasma lipoproteins. However, in Group B they significantly determined the variation of plasma TC and LDL-C levels (in about 28% and 29%, respectively). Exclusively in Group B TSH was significant associated with osteocalcin levels (r=0.336, P<0.05). We concluded that TSH and osteocalcin are engaged in determination of more healthy lipid profile at a certain level of insulin sensitivity. Verf.-Referat