Gender-dependent effects of exercise training on serum leptin levels in humans

Abstract

Leptin, the product of the ob gene, is elevated in obese humans and appears to be closely related to body fat content. The purpose of the present investigation was to determine the effect of aerobic exercise training on systemic leptin levels in humans. Eighteen sedentary middle-aged men (n = 9) and women (n = 9) who did not differ in aerobic capacity (29.4 +/- 1.2 vs. 27.5 +/- 1.2 ml x kg(-1) x min(-1)) or insulin sensitivity index (3.41 +/- 1.12 vs. 4.88 +/- 0.55) were studied. Fat mass was significantly lower in females vs. males (21.83 +/- 2.25 vs. 26.99 +/- 2.37 kg, P < 0.05). Despite this, fasting serum leptin was significantly higher in the females vs. males (18.27 +/- 2.55 vs. 9.88 +/- 1.26 ng/ml, P < 0.05). Serum leptin concentration decreased 17.5% in females (P < 0.05) after 12 wk of aerobic exercise training (4 day/wk, 30-45 min/day) but was not significantly reduced in males. Fat mass was not altered after training in either group. In contrast, both aerobic capacity (+13% males, +9.1% females) and insulin sensitivity (+35% males, +82% females) were significantly improved subsequent to training. These data suggest that 1) women have higher circulating leptin concentrations despite lower fat mass and 2) exercise training appears to have a greater effect on systemic leptin levels in females than in males.

Leptin resistance in obese humans: does it exist and what does it mean?

“…Of course, there may still be ample potential for such agents to achieve a therapeutic bene®t, but perhaps leptin or NPY receptor antagonists will be of most bene®t in those who are attempting to restrain their energy intake and increase the amount of exercise that they take. In these subjects, there is a reduction in leptin levels 10,11,41,42 which will oppose their efforts, but they will also become more sensitive to exogenous leptin, and indeed to other anti-obesity agents that act via physiological mechanisms. Drugs which are most effective in those who help themselves would obviously be more acceptable ethically and less liable to abuse than those which might endorse a life of gluttony and sloth.…”

Exercise and Weight Loss: What Is the Evidence of Sex Differences?

“…In one of the first human studies designed to assess exercise-induced sex differences in appetite hormones, Hickey et al [23] exercised men and women for 12 weeks (4 days/wk, 45 minutes/day). Exercise significantly lowered (approximately -18 %) leptin and insulin concentrations in women.…”

Leptina: o diálogo entre adipócitos e neurônios

“…Porém, diversos mecanismos fisiológicos influenciam a síntese aguda da leptina e conseqüentemente, levam a oscilações nas quantidades de leptina intrinsecamente associadas com a massa de gordura. Jejum, exercício físico moderado e frio resultam numa diminuição da expressão do gene da leptina e eventual queda nas concentrações plasmáticas da proteína (17,18). Alimentação após jejum, glicocorticóides e insulina são fatores que estimulam a transcrição do gene e a produção de leptina (19)(20)(21).…”