Delayed increase in inflammation and thenar VO2 in marathon runners

Abstract

Introduction: The muscle-specific inflammatory response after strenuous exercise has some similarity with those observed in sepsis and it is used as a mirror of sepsis-specific inflammatory response. Near-infrared spectroscopy (NIRS) has been used to quantify sepsis-induced metabolic alterations by measuring variations of tissue oxygen saturation (StO 2) during a vascular occlusion test (VOT). We aimed to investigate whether NIRS dynamic variables could reflect the magnitude of inflammatory process that follows strenuous exercise in marathon runners. Methods: VOT-NIRS (InSpectra Model 650) measurement was performed before, at the finish line and on the day after the marathon in 13 runners (10 males/three females). VOT-derived NIRS traces were analyzed for StO 2 -downslope (R dec StO 2) and StO 2 -upslope (R inc StO 2). Blood samples were collected to measure C-reactive protein (CRP), procalcitonin (PCT), white blood cells (WBC), creatine kinase (CK), and lactate. Data are mean +/- SD (in Table 1, median (IQR)). P <0.05 was considered statistically significant. Results: The results of NIRS dynamic and hemodynamic variables are shown in Table 1. R dec StO 2 was significantly increased in the day after the marathon. Significant increases in lactate (2.7 +/- 0.5 vs 1.2 +/- 0.3) and WBC (14 x 10 3 +/- 4 vs 5 x 10 3 +/- 2) were observed after the completion of the marathon. Serum CRP, PCT and CK were significantly increased on the day after the marathon (0.6 +/- 0.6 vs 12 +/- 8; 0.09 +/- 0.2 vs 0.7 +/- 0.9; 398 +/- 198 vs 1,932 +/- 1,620), indicating the muscle-specific inflammatory response as a result of muscle damage. Conclusions: Delayed increase in thenar VO 2 2 is associated with musclespecific inflammatory response after strenuous exercise as a result of the muscle damage. {Table presented}.