The aim of the present study was to assess the influence of regular physical activity on ghrelin concentration and the interrelationships between ghrelin and metabolic and biochemical parameters in boys.
In total, 56 healthy schoolboys aged between 10 and 16 years were divided into the swimming (n = 28) and the control (n=28) groups. The subjects were matched by age and body mass index (BMI), generating 9 matches pairs in pubertal group I (Tanner stage I), 11 pairs in group II (pubertal stages 2 and 3) and 8 pairs in group III (pubertal stages 4 and 5). Plasma ghrelin levels were significantly higher in the swimmers group II and II than controls (group II: 1126.8+- 406 vs 803.3+-411,2 pg/ml; group III: 1105.5+-337.5 vs 850.8+-306 pg/ml). Ghrelin was significantly correlated with VO2peak in control group ( r = -0.530; p < 0.05), while not in the swimmwrs group. From biochemical parameters ghrelin was significantly related to testosterone ( r = - 0.596), IGF-1 ( r = - 0.656) and IGFBP-3 ( r = -0.494). No relationships were observed in the swimmers group between ghrelin and biochemical parameters. In conclusion, ghrelin concentration decreased during puberty in physically inactive boys
