Leptin is related to body fat content in male distance runners. Hickey, Matthew S., Robert V. Considine, Richard G. Israel, Tyson L. Mahar, Michael R. McCammon, Gilian L. Tyndall, Joseph A. Houmard, and Jose F. Caro. Human Performance Laboratory, Department of Exercise and Sport Science, School of Health and Human Performance, East Carolina University, Greenville, NC 27858, Division of Endocrinology and Metabolism, Department of Medicine, Jefferson Medical College of Thomas Jefferson University, Philadelphia, PA 19107, Department of Exercise and Sport Science, Colorado State University, Fort Collins, CO 80523
APStracts 3:0183E, 1996.
Leptin, the product of the ob gene, has been reported to be related to body fat in humans (Considine, et al. NEJOM, 334: 292, 1996). However, little is known about the physiology of this putative satiety signal in humans. The purpose of the present study was to determine whether leptin in related to body fat content in relatively lean, endurance trained adults. In addition, the effect of acute exercise on circulating leptin concentration was studied. Thirteen male runners, whose mean age, height, weight, %fat, and VO2max were 32.2+/-2.5 y, 176.2+/-1.6 cm, 71.9+/-6.9 kg, 9.7+/-0.9%, and 62.9+/ -2.2 ml[lambda]kg-1[lambda]min-1, respectively, were studied. Blood samples were obtained following an overnight fast and again immediately following the completion of a 20 mile run at 70% VO2max under controlled environmental conditions. Serum leptin was closely related to fat mass (r=0.92) in the runners. Acute exercise had no detectable effect on serum leptin levels (PRE = 2.19+/-0.32 ng[lambda]ml-1, POST = 2.14+/-0.36 ng[lambda]ml-1). These data indicate that even at a biological extreme of body fat, circulating leptin concentration is closely related to fat content. Further, the data suggest that in trained individuals with low leptin concentrations, acute exhaustive exercise has no immediate effect on circulating leptin concentration.

Received 6 June 1996; accepted in final form 1 August 1996.
APS Manuscript Number E277-6.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 19 September 1996