Plasma adiponectin and leptin concentrations in professional rugby players

Adipose tissue synthesizes and secretes a number of cytokine hormones, defined adipokines, which have emerged as critical regulators of several metabolic functions, including energy homeostasis, insulin action and lipid metabolism. The present study is aimed at assessing the relationship between plasma concentrations of leptin and adiponectin and body composition in a cohort of 38 male professional rugby players (age: 22-35 years). Anthropometric evaluation included body mass index (BMI, range: 23.4-35.1 kg/m2) and whole body bioelectric impedance to determine absolute fat-free mass (FFM), absolute fat mass (FAT), relative percentage of fat mass (FAT percent) and fat-free mass (FFM percent). FAT percent ranged from 15 to 34 percent, corresponding to a FAT of 11.5-38.7 kg, whereas FFM range was 62.1-83.5 kg. Plasma leptin range was 1.2-4.3 ng/mL and adiponectin range was 2.0-16.6 microg/mL. Plasma leptin and adiponectin concentrations and their ratio did not correlate with BMI, nor with FAT, FAT percent, FFM and FFM percent, even after correction for BMI. The findings of this study suggest that in professional rugby players some additional factors, like neuroendocrine adaptations, other than adipose mass play a relevant role in the determination of adipokine levels, which in this group appear to be rather independent of body composition.