The Soluble Leptin Receptor of Regular Exercisers

Abstract

This study examined the concentrations and the relationships of soluble leptin receptor (sLR) and leptin levels among both physically active people and lean sedentary persons. Information collected for this study came from twelve joggers (JOG), ten weight trainers (WET) and eleven lean sedentary persons (CON). Regular exercisers were defined as those who consistently participated in jogging or weight training 30 minutes a day, at least four times a week, for a period of no less than three years prior to the study. The CON group was defined as exercising, at most, one time per week, less than 20 minutes each time if at all. Leptin and sLR were analyzed using enzyme-linked immunosorbent assay. The results show the BMI of the WET group to be higher than the other groups, yet their percent body fat was not significantly different. Although sLR levels of the JOG group were higher than the WET and CON groups, their free leptin index (FLI) did not show a significant difference. The sLR levels for joggers were higher than the weight trainers. The sLR concentration or the ratio of sLR to fat mass may be an alternative index to FLI for comparing physically active and lean people.

Key words

percent body fat - physically active people - free leptin index

References

• 1 Banerji M A, Faridi N, Atluri R, Chaiken R L, Lebovitz H E. Body composition, visceral fat, leptin, and insulin resistance in Asian Indian men.  J Clin Endocrinol Metab. 1999;  84 137-144
• 2 Chan J L, Bluher S, Yiannakouris N, Suchard M A, Kratzsch J, Mantzoros C S. Regulation of circulating soluble leptin receptor levels by gender, adiposity, sex steroids, and leptin: observational and interventional studies in humans.  Diabetes. 2002;  51 2105-2112
• 3 Clement K, Vaisse C, Lahlou N, Cabrol S, Pelloux V, Cassuto D, Gourmelen M, Dina C, Chambaz J, Lacorte J M, Basdevant A, Bougneres P, Lebouc Y, Froguel P, Guy-Grand B. A mutation in the human leptin receptor gene causes obesity and pituitary dysfunction.  Nature. 1998;  17 398-401
• 4 Considine R V, Sinha M K, Heiman M L, Kriauciunas A, Stephens T W, Nyce M R, Ohannesian J P, Marco C C, McKee L J, Bauer T L, Caro J F. Serum immunoreactive-leptin concentrations in normal-weight and obese humans.  New Engl J Med. 1996;  334 292-295
• 5 Halaas J L, Gajiwala K S, Maffei M, Cohen S L, Chait B T, Rabinowitz D, Lallone R L, Burley S K, Friedman J M. Weight-reducing effects of the plasma protein encoded by the obese gene.  Science. 1995;  269 543-546
• 6 Huang L, Wang Z, Li C. Modulation of circulating leptin levels by its soluble receptor.  J Biol Chem. 2001;  276 6343-6349
• 7 Lahlou N, Landais P, De Boissieu D, Bougneres P F. Circulating leptin in normal children and during dynamic phase of juvenile obesity: relation to body fatness, energy metabolism, caloric intake, and sexual dimorphism.  Diabetes. 1997;  46 989-993
• 8 Lammert A, Kiess W, Bottner A, Glasow A, Kratzsch J. Soluble leptin receptor represents the main leptin biding activity in human blood.  Biochem Biophys Res Commun. 2001;  283 982-988
• 9 Lee G H, Proenca R, Montez J M, Carroll K M, Darvishhzadeh J G, Lee J I, Friedman J M. Abnormal splicing of the leptin receptor in diabetic mice.  Nature. 1996;  379 632-635
• 10 Maffei M, Halaas J, Ravussin E, Pratley R E, Lee G H, Zhang Y, Fei H, Kim S, Lallone R, Ranganathan S, Kern P A, Friedman J M. Leptin levels in human and rodent: measurement of plasma leptin and ob RNA in obese and weight-reduced subjects.  Nature Med. 1995;  1 1155-1161
• 11 Mann D R, Johnson A O, Gimpel T, Castracane V D. Changes in circulating leptin, leptin receptor and gonadal hormones from infancy until advanced age in humans.  J Clin Endocrinol Metab. 2003;  88 3339-3345
• 12 Neuhauser-Berthold M, Herbert B M, Luhrmann P M, Sultemeier A, Blum J F, Hebebrand J. Resting metabolic rate, body composition, and serum leptin concentration in a free-living elderly population.  Eur J Endocrinol. 2003;  142 486-492
• 13 Ogier V, Ziegler O, Mejean L, Nicolas J P, Stricker-Krongrad A. Obesity is associated with decreasing levels of the circulating soluble leptin receptor in humans.  Int J Obes Relat Metab Disord. 2002;  26 496-503
• 14 Pelleymounter M A, Cullen M J, Baker M B, Hecht R, Winters D, Boone T, Collins F. Effects of the obese gene product on body weight regulation in ob/ob mice.  Science. 1995;  269 540-543
• 15 Schroth M, Kratzsch J, Groschl M, Rauh M, Rascher W, Dotsch J. Increased soluble leptin receptor in children with nephritic syndrome.  J Clin Endocrinol Metab. 2003;  88 5497-5501
• 16 Sinha M K, Opentanova I, Ohannesian J P, Kolaczynski J W, Heiman M L, Hale J, Becker G W, Bowsher R R, Stephens T W, Caro J F. Evidence of free and bound leptin in human circulation. Studies in lean and obese subjects and during short-term fasting.  J Clin Invest. 1996;  1598 1277-1282
• 17 Tartaglia L A. The leptin receptor.  J Biol Chem. 1997;  272 6093-6096
• 18 van Dielen F M, van't Veer C, Buurman W A, Greve J W. Leptin and soluble leptin receptor levels in obese and weight-losing individuals.  J Clin Endocrinol Metab. 2002;  87 1708-1716
• 19 Zhang Y, Proenca R, Maffei M, Barone M, Leopold L, Friedman J M. Positional cloning of the mouse obese gene and its human homologue.  Nature. 1994;  372 425-432