Body composition, maximal aerobic performance and inflammatory biomarkers in endurance-trained athletes

This study was designed to examine the relationships between body composition, cardiorespiratory fitness and simultaneously measured inflammatory parameters in endurance-trained athletes. In 20 well-trained rowers (19<bold></bold>0 +/- 2<bold></bold>9years; 185<bold></bold>6 +/- 4<bold></bold>8cm; 85<bold></bold>7 +/- 10<bold></bold>8kg; 17<bold></bold>1 +/- 5<bold></bold>1% body fat; maximal oxygen consumption [VO(2)max]: 63<bold></bold>9 +/- 8<bold></bold>5mlmin(-1)kg(-1)), body composition was measured by dual-energy X-ray absorptiometry and cardiorespiratory fitness by direct VO(2)max test. Twelve inflammatory factors [interleukin (IL)-2, IL-4, IL-6, IL-8, IL-10, vascular endothelial growth factor, interferon-gamma (IFN-), tumour necrosis factor-alpha, IL-1, IL-1, monocyte chemoattractant protein-1 (MCP-1), epidermal growth factor (EGF)] were analysed from serum samples. Serum IFN- was related (P<0<bold></bold>05) to fat-free mass (FFM) (r=-0<bold></bold>56) and muscle mass (r=-0<bold></bold>50). The stepwise regression analysis showed that IFN- explained 27<bold></bold>5%, and IFN- and IL-6 together explained 39<bold></bold>8% of the variability of FFM, while IFN- explained 21<bold></bold>1%, and IFN- together with EGF explained 36<bold></bold>6% of the variability of muscle mass in male rowers. Serum IL-8 (r=-0<bold></bold>65) and VEGF (r=-0<bold></bold>48) correlated (P<0<bold></bold>05) with VO(2)maxkg(-1). Serum IL-8 explained 38<bold></bold>5% of the variability of VO(2)maxkg(-1). Significant correlations were also found among several inflammatory parameters, indicating that various inflammatory cytokines act on the body as an ensemble. In conclusion, this cross-sectional study in endurance-trained male rowers showed that FFM and muscle mass were negatively correlated with serum IFN- level, whereas cardiorespiratory fitness was negatively related to serum IL-8 level.