Body composition and weakness of hand grip strength and pinch strength in patients with chronic kidney disease from different ethnic backgrounds

Background Chronic kidney disease (CKD) patients commonly report muscle weakness and fatigue. Losing muscle mass increases mortality. Accordingly, we aimed to determine the main factors associated with loss of muscle mass and muscle weakness. Methods Anthropometric measurements were made in CKD patients attending a specialised clinic, along with hand grip strength (HGS), pinch strength (PS) and body composition (muscle mass and fat mass), using segmental bioimpedance assessment. Results We reviewed the results of 161 CKD patients; 105 male (65.2%), mean (SD) age 70.3 (15) years, body mass index (BMI) 28.8 (6.7) kg m(-2). In multivariable models, both HGS and PS were independently negatively associated with age [standardised beta (St beta) = 0.35; 95% confidence limits (CL) = -0.32 to -0.14; St beta = 0.38; 95% CL = -0.65 to -0.02;P < 0.001, respectively] and positively with appendicular muscle in the arm tested [St beta = 0.34; 95% CL = 2.5-6.3; St beta = 0.24; 95% CL = 0.17-0.98;P P = 0.006, respectively]. In addition, HGS was associated with male gender (St beta = 0.19; 95% CL = 0.7-7.5;P = 0.019] and negatively with percentage body fat (St beta = 0.22; 95% CL = -0.36 to -0.07;P = 0.003]. There were 47 (29.2%) Asian patients who had lower total skeletal muscle mass/height ratio and appendicular muscle mass/BMI ratio compared to other ethnicities [9.6 (1.8) versus 10.5 (1.6) kg m(-2),P < 0.01; 0.73 (0.23) versus 0.83 (0.33) m(2);P < 0.01). Conclusions In CKD patients, we found that muscle weakness measured by HGS and PS was associated with increasing age and loss of appendicular muscle mass. HGS was also weaker with increasing fat mass and female gender, whereas PS was weaker in patients of Asian ethnicity.