Relation of plasma leptin concentrations to sex, body fat, dietary intake,and peak oxygen uptake in young adult women and men

The purpose of this study was to examine:the relation of leptin to metaboli c and dietary factors in college-age adults. Young adult women and men (n = 32) were recruited and underwent testing for measurement of body mass inde x, body composition, peak oxygen consumption (VO(2)peak), dietary intake, a nd plasma levels of leptin and insulin. Ln leptin was significantly greater for women than for men (2.1 versus 1.2 ng/mL, respectively). This differen ce remained significant even after adjusting In leptin for fat mass and fat -free mass as covariates in separate analyses. VO(2)peak was higher for men than for women and this remained significant after adjustment for differen ces in fat-free mass and total body mass. Significant correlations were fou nd between In leptin and indicators of fat mass in women and men, with high er correlations for similar variables observed in men (r = 0.548, 0.674, an d 0.732 for body mass index, percentage of body fat, and fat mass [kg] for women, respectively, and r = 0.740; 0.888, 0.858 for body mass index, perce ntage of body fat, and fat mass [kg] for men, respectively). Ln leptin show ed a significant inverse relationship with VO(2)peak (r = -0.751) in men on ly. After adjusting In leptin for body fat mass using partial correlations, In leptin was not significantly associated with any of the measured variab les. Alternatively, after normalization of In leptin using fat mass as the divisor, a less adequate statistical analysis method, men showed statistica l significant correlations between In leptin and dietary,intake and VO(2)pe ak. Although plasma leptin values were higher in women, stronger associatio ns were evident for men than for women between leptin and metabolic and die tary factors. (C) Elsevier Science Inc. 2001.