Phoenixin's influence on HPG axis and inflammation in elite ice hockey athletes: A cross-sectional analysis

The neuropeptide phoenixin (PNX) may be involved in regulating the hypothalamic-pituitary-gonadal (HPG) axis and inflammatory responses. This study aims to investigate the role of PNX in the regulation of HPG axis function in ice hockey players and its impact on body composition. This cross-sectional study included 65 male ice hockey players aged 18-22, divided into untrained, non-elite athlete, and elite athlete groups. Body composition was assessed using bioelectrical impedance analysis, and plasma levels of PNX, gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH), testosterone, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-10 (IL-10) were measured by enzyme-linked immunosorbent assay. Elite ice hockey players exhibited significantly higher lower limb and core skeletal muscle mass, skeletal muscle index, and testosterone levels, aligning with the high-intensity intermittent nature of hockey training. Compared to the non-training group, ice hockey training groups showed elevated levels of PNX, GnRH, testosterone, and TNF-α, along with reduced levels of LH and IL-6. PNX concentration positively correlated with lean body mass, skeletal muscle mass, skeletal muscle index, serum GnRH, and testosterone levels, and negatively correlated with serum LH and IL-6 levels. In conclusion, PNX may enhance skeletal muscle mass in ice hockey players, particularly in the lower limbs and core muscles, by promoting HPG axis activity while inhibiting inflammatory responses and reducing HPG axis suppression. These findings provide new insights into the physiological adaptation mechanisms of ice hockey players, potentially aiding in the optimization of training strategies and improvement of athletic performance.