Effects of anabolic-androgenic steroid use or gonadal testosterone suppression on serum leptin concentration in men

Lipid Laboratory, Department of Internal Medicine, University of Cape Town Medical School, Anzio Road, Observatory, 7925, South Africa.

OBJECTIVE: Serum leptin concentration shows a sexual dimorphism that is not accounted for by gender differences in adiposity. A strong inverse association exists between serum leptin and testosterone concentrations in men, pointing to a likely influence of gonadal sex steroids on serum leptin concentration. The aim of this study was to investigate whether manipulation of sex steroid hormones in men would alter serum leptin concentration independently of changes in fat mass. DESIGN AND METHODS: The effects of sex steroid suppression on serum leptin concentration were investigated in nine healthy men in whom testosterone had been reversibly suppressed for 5 weeks after treatment with intramuscular triptorelin. The effects of sex steroid supplementation were investigated in nine male bodybuilders who self-administered anabolic--androgenic steroids (AAS) for a mean period of 6.5 weeks. A control group received no hormonal treatment. RESULTS: Testosterone concentration was significantly reduced by triptorelin administration (7.32+/- 1.92ng/ml at baseline compared with 1.15+/-0.57ng/ml at 5 weeks, P=0.002). High-dose AAS use was confirmed by urine analysis. Body fat percentage was unaffected by the AAS or triptorelin intervention (P>0.19). Leptin concentration was significantly reduced after one cycle of AAS use (2.40+/-0. 98ng/ml off cycle compared with 1.63+/-0.37ng/ml on cycle, P=0.012), and was significantly increased by triptorelin administration (2. 96+/-1.50ng/ml at baseline compared with 6.63+/-4.67ng/ml at five weeks, P=0.004). No significant change occurred in the control group. CONCLUSION: Androgenic sex hormone supplementation decreases serum leptin concentration, whereas suppression increases serum leptin concentration, independently of changes in body fat mass in healthy men. The sexual dimorphism evident in serum leptin concentration is likely to be due to a suppressive effect of testosterone on serum leptin concentration in males.

This article has been cited by other articles:

				A. E. Rigamonti, S. M. Bonomo, D. Scanniffio, S. G. Cella, and E. E. Muller Orexigenic effects of a growth hormone secretagogue and nitric oxide in aged rats and dogs: correlation with the hypothalamic expression of some neuropeptidergic/receptorial effectors mediating food intake. J. Gerontol. A Biol. Sci. Med. Sci., April 1, 2006; 61(4): 315 - 322. [Abstract] [Full Text] [PDF]

				K. C McCowen, P. R. Ling, C. Friel, J. Sternberg, R A. Forse, P. A Burke, and B. R Bistrian Patterns of plasma leptin and insulin concentrations in hospitalized patients after the initiation of total parenteral nutrition Am. J. Clinical Nutrition, May 1, 2002; 75(5): 931 - 935. [Abstract] [Full Text] [PDF]