Abstract: Objectives To investigate the correlation between serum 25 hydroxyvitamin D [25(OH)D] level and handgrip strength (HGS) and pinch strength (PS) in maintenance hemodialysis (MHD) patients.  Method  This was a single-center and cross-sectional study. Patients undergoing MHD in the month of March 2021 in our Hemodialysis Center were enrolled in this study. Demographic data of the patients were collected. Routine blood counts, serum biochemical parameters and 25(OH)D levels (by electrochemiluminescence immunoassay) were determined before dialysis. HGS and PS were measured using a dynamometer. Patients were categorized into 25(OH)D normal, 25(OH)D insufficient, and 25(OH)D deficient groups based on 25(OH)D levels. Differences in these indexes were compared among the 3 groups. Spearman correlation analysis and linear regression were applied to evaluate the correlation between 25(OH)D level and HGS and PS.  Results  A total of 126 MHD patients were included in this study; 28 patients (22.22%) in the normal 25(OH)D group, 42 patients (33.33%) in the insufficient group, and 56 patients (44.44%) in the deficient group. Spearman correlation analysis suggested that serum 25(OH)D level was positively correlated with HGS (r=0.289, P=0.001) and PS (r=0.289, P=0.001). After adjusting for relevant confounders, multivariate linear regression showed that lower serum 25(OH)D level was independently associated with lower HGS (β=0.199, 95% CI:0.058～0.341, P=0.006) and PS (β=0.052, 95% CI：0.017～0.087, P=0.004).   Conclusion  Reduced serum 25(OH)D level was an independent factor for reduced HGS and PS in MHD patients.

Key words: 25(OH)D, Handgrip strength, Pinch strength, Muscle health, Maintenance hemodialysis