Physical Fitness Is Independently Related to Blood Leptin Concentration and Insulin Sensitivity Index in Male Subjects with Central Adiposity

Abstract

Aim: To compare the maximal power output (MPO) of subjects presenting a central adiposity to those of controls and to study the links between plasma leptin or indices of insulin sensitivity (QUICKI) and physical fitness (PF). Methods: MPO was determined for 169 middle-aged men divided into two groups according to waist circumference (WC– < 94 cm, WC+ ≧ 94 cm) each subdivided in two subgroups with low and high PF (WC-L, WC-H, WC+L, WC+H) determined from the median MPO relative to fat free mass (3.06 W/kg_FFM). Results: MPO (W/kg_FFM) was lower in WC+ than in WC–. Expressed relative to fat mass, leptin was lower and QUICKI higher in WC– than in WC+. In WC+H, leptin and QUICKI were significantly less disturbed than in WC+L and were independently correlated to MPO (r = –0.36 and r = 0.32 respectively; p < 0.001). In WC+, when visceral perimeter was added to the analysis, the relationships MPO/leptin remained significant but not MPO/QUICKI. Conclusion: The low PF in subjects with abdominal obesity is independently linked to plasma leptin and insulin sensitivity even if leptin and insulin may share common pathways in their peripheral effects. Visceral adiposity participates to the link between MPO and QUICKI, but not between MPO and leptin.