Plasma leptin in moderately obese men: independent effects of weight loss and aerobic exercise.
The independent effects of weight loss and exercise on plasma leptin and total (AT), subcutaneous (SAT), and visceral (VAT) adipose tissue were investigated in 52 obese men. Subjects were randomly assigned to four 12-wk protocols: 1) control (C, n = 8), 2) diet-induced weight loss (DWL, n = 14), 3) exercise-induced weight loss (EWL, n = 14), and 4) exercise with weight maintenance (EWS, n = 16). Plasma leptin was unchanged in C (from 7.8 +/- 1.3 to 7.7 +/- 1.0 ng/ml). Equivalent weight loss (7.5 kg) decreased leptin significantly but similarly (DWL, from 8.5 +/- 1.0 to 4.8 +/- 0.6 ng/ml; EWL, from 10.1 +/- 1.0 to 5.0 +/- 0.6 ng/ml). Exercise in the absence of weight loss did not alter leptin levels (from 10.1 +/- 1. 3 to 9.2 +/- 1.2 ng/ml). Changes in leptin correlated with changes in AT and SAT (both P < 0.05) but not in VAT. We conclude that reduction in adipose tissue after weight loss results in a collateral decrease in circulating leptin, and exercise, independent of its effects on weight loss, has no profound influence on leptin secretion.
Department of Human Biology and Nutritional Sciences, University of Guelph, N1G 2W1, Kingston, Ontario, Canada K7L 3N6. fthong@uoguelph.ca
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Thong
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Hudson
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Ross
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Janssen
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Graham
D000273:Adipose Tissue / Q000378:metabolism; D000328:Adult; D000886:Anthropometry; D001823:Body Composition / Q000502:physiology; D004038:Diet, Reducing; D015444:Exercise / Q000502:physiology*; D006801:Humans; D020738:Leptin / Q000097:blood*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000097:blood*; D015431:Weight Loss / Q000502:physiology*
D020738:Leptin