Effect of endurance exercise on blood levels of leptin in women and men

: Leptin is a peptide hormone secreted by adipose tissue which takes part in regulation of food intake and energy expenditure. The aim of the study was to evaluate an endurance exercise influence on leptin levels and its relation with lipids parameters and energy expenditure during an effort. Forty two cyclists (16 women and 26 men) have performed a progressive test. Before and after an effort the blood was taken to evaluation of leptin level and lipid profile. During the test and the recovery ventilation, maximal oxygen uptake, heart rate and energy utilization were analyzed. All parameters were analyzed in whole cyclists' group and in women and men groups separately. We have observed that in women the leptin concentration in serum were significantly higher than in men before exercise as well as after an effort. Moreover female cyclists showed a reduction in leptin levels after progressive test compared with any changes in men cyclists. In the whole group, after an effort, we observed a positive correlation between leptin levels and BMI and apoB, but a negative correlation with energy expenditure and VO2max. We have also noted a positive correlation between energy expenditure and VO2max. In conclusion we can say that the negative correlation between leptin and energy expenditure, ventilation and maximal oxygen uptake is related to physical performance. The decrease of serum leptin in women without any changes in men could have been mediated by gender differences in body fat tissue as well as hormonal (influence of catecholamins, cortisol, thyroid hormones and growth hormone on adipose tissue, augmentation of testosterone in men) and peripheral mechanisms (decrease of glucose or insulin and increase of fatty acids).