Comparison of Muscle Damage Markers and Myokines between Adult and Middle-Aged Marathon Runners

This study compared markers of muscle damage and myokines between adult and middle-aged runners before and after the marathon. Seventy-four male runners: 48 adults aged 30-44 years (AA group), and 26 middle-aged individuals aged 45-59 years (MA group) participated of the study. Blood samples were collected 24 hours before, immediately after, 24 hours and 72 hours after the marathon to measure skeletal and cardiac muscle damage markers (CK, LDH, troponin, and proBNP) and myokines (IL-6, IL-15, decorin, BDNF, GDF-15, FGF-21, apelin, musclin, myostatin, and follistatin). Before the marathon, it was observed that serum concentrations of BDNF were higher, and those of IL-15, GDF-15, apelin, and musclin were lower in the MA group. Immediately after the marathon, both groups showed higher activity of CK and LDH, as well as higher serum concentrations of ProBNP, troponin, IL-6, decorin, FGF-21, BDNF, and GDF-15. After the marathon and in the recovery period, GDF-15 concentrations remained lower and BDNF concentrations higher in the MA group compared to the AA group. In both groups, long-distance running induced muscle and cardiac damage and modulated myokines responsible for skeletal and cardiac muscle repair/adaptation. Middle-aged individuals show a reduction in the serum concentration of myokines that may contribute to muscle and cardiometabolic dysfunction in senescence. The role of higher levels of BDNF in middle-aged runners on cardiometabolic adaptation should be investigated to elucidate the molecular mechanisms of senescence.