P1573EFFECT OF INFLAMMATION ON MUSCLE-BONE INTERACTIONS IN HEMODIALYSIS PATIENTS

Abstract

Abstract Background and Aims Chronic hemodialysis patients show decreased muscle mass, low physical activity and chronic weakness. Hemodialysis treatments results in increased risk of inflammation, which impairs physical activity. The calcium-phosphate and bone metabolism, as well as muscle mass, are regulated by a range of factors like FGF-23 and its co-factor Klotho protein, myostatin, follistatin and sclerostin. Complex interactions between these cytokines and inflammation have been described. The aim of the study was to assess the influence of inflammation on plasma concentrations of factors that regulate muscle and bone-mineral metabolism Method 55 hemodialysis patients were divided into study group (32 patients) and the reference group (23 patients). The former were the patients who had inflammation confirmed by plasma CRP >50 mg /L. Blood was collected before and after hemodialysis during the inflammation, and before hemodialysis after the resolution of inflammation Results Mean CRP in study group was 105.9±73.9 mg/l. The mean period between blood sampling during inflammation and resolution of inflammation was 15±7.9 days. Statistically significant increase of plasma cFGF-23 concentration was observed after hemodialysis. Its median concentration increased from 1992.8 RU/ml; IQR = [1350; 4320 RU/ml] before hemodialysis to 2421.3 RU/ml IQR = [1351; 7348 RU/ml] after HD (p = 0.001). Significant increase of sclerostin was observed after hemodialysis. Serum sclerostin increased from 1346.2 pg/ml IQR = [1034; 2243 pg/ml] before HD to 1583.8 pg/ml IQR = [1198; 2559 pg/ml] after HD (p = 0.002). Follistatin concentration increased from 2669 pg/ml IQR = [2129; 5702 pg/ml] before HD to 4220.5 pg/ml IQR = [2583; 6727 pg/ml] (p = 0.009). Hemodialysis had no significant effect on plasma Klotho protein, iFGF-23, FGF-21, and myostatin. After the resolution of inflammation there was statistically significant decrease in FGF-21 from 3591.4 pg/ml. IQR = [1174.3; 6,537.3 pg/ml] to 2454 pg/ml IQR = [1221.1; 3448.4 pg/ml] p = 0.006). There were significant changes of the concentration of Klotho protein, cFGF-23, iFGF-23, sclerostin, myostatin, follistatin after the resolution of inflammation vs. baseline. Conclusion Hemodialysis modulates the concentration of factors involved in regulation of calcium-phosphate metabolism, bone turnover and muscle growth and strength. The resolution of inflammation in hemodialysis patients leads to the decrease of plasma FGF-21 concentration.