Effects of full Marathon on striated muscle and renal function of Marathon amateurs without complaints

Objective To approach the effects of full Marathon on striated muscle and renal function of Marathon amateurs without complaints. Methods A prospective self-paired design study was conducted. The amateurs without body discomfort, hematuria, brown urine, or persistent muscle pain within 1 week after the 2012 Xiamen International Marathon Race were enrolled voluntarily. The peripheral blood and random urine specimens of all subjects under static status 1 week before the race and after the race instantly (within 10 minutes after finishing the race) were collected to detect markers of renal function and striated muscle injury. Results Sixty-one subjects were included in the final analysis of the study with full Marathon of 42.195 km and mean race time of (297.05±55.60) minutes. Compared with those under static status before the race, the markers of renal function including the levels of urinary N-acetyl-beta-D-glucusamidase [NAG (U/L): 64.00 (54.50, 85.50) vs. 9.50 (8.10, 11.50)], urinary β2-microspheres protein [β2-MG (μg/L): 261.00 (128.50, 1 608.00) vs. 66.60 (33.75, 123.00)], random urinary creatinine [UCr (μmol/L): 19 066.56±10 938.31 vs. 5 872.52±4 363.20] and serum creatinine [SCr (μmol/L): 129.97±25.84 vs. 97.39±14.51] immediately after the race were significantly increased (all P < 0.01); the markers of muscle injury including the levels of serum creatine kinase [CK (U/L): 864.00 (504.00, 1 644.00) vs. 164.00 (128.00, 256.00)], lactic dehydrogenase [LDH (U/L): 383.26±141.69 vs. 182.23±41.12], myoglobin [Mb (mg/L): 1 880.00 (1 080.00, 3 300.00) vs. 42.00 (36.00, 54.50)], alanine aminotransferase [ALT (U/L): 27.0 (19.5, 38.0) vs. 24.0 (15.0, 29.5)] and aspartate transaminase [AST (U/L): 52.07±25.13 vs. 28.28±11.86] were also significantly increased (all P < 0.01), and the increase in CK, Mb, and LDH were more significant. It was shown by correlation analysis that CK after race was negatively correlated with age (r = -0.352, P = 0.005) and body mass index (r = -0.271, P = 0.035), and it was positively correlated with racing time (r = 0.387, P = 0.002) and urinary β2-MG after the race instantly (r = 0.364, P = 0.004). Mb after race was negatively correlated with body mass index (r = -0.331, P = 0.009), and it was positively correlated with urinary β2-MG after the race instantly (r = 0.315, P = 0.013). LDH after race was negatively correlated with age (r = -0.275, P = 0.032) and body mass index (r = -0.377, P = 0.003), and it was positively correlated with urinary β2-MG after the race instantly (r = 0.424, P = 0.001). Conclusion Full Marathon could significantly impact striated muscle and renal function of Marathon amateurs without complaints. Key words: Full Marathon; Rhabdomyolysis; Renal function; Creatase