Sex Differences in Handgrip Strength in Nondialysis-Dependent CKD

Background: Handgrip strength (HGS) is a simple, reliable measure of skeletal muscle function and a surrogate marker of protein-energy status and functional status in patients with chronic kidney disease (CKD). We assessed HGS using the NIH Toolbox grip strength test in CKD patients. Methods: We studied 105 individuals (49.5% women) with CKD stage 3b-4 (eGFR 15-44 ml/min/1.73m2). HGS was measured using the NIH Toolbox grip strength test, a standardized and validated test in the US population, with the Jamar Plus Digital dynamometer. Results: The mean (SD) age and eGFR were 61 ± 12 years and 34.9 ± 9.8 mL/min/1.73m2. When compared to the NIH Toolbox reference population, CKD participants scored, on average, below the 50th percentile on HGS in both the dominant and nondominant hand. Women scored in a significantly lower percentile than men, p<0.0001. When adjusted for age, sex, race/ethnicity, and education level, women had a higher dominant mean grip strength score than men but this was not statistically significant. There were no significant differences in HGS between participants with CKD stage 3b or 4. Conclusion: Participants with CKD have lower HGS when compared to the general population, with women scoring in a significantly lower percentile than men. Women tended to have greater dominant grip strength compared to men, but this was not statistically significant. Further studies are needed to study sex differences in skeletal muscle function in CKD. Funding: Other NIH Support - NHLBI - MenAdjusted Score Men Percentile WomenAdjusted Score WomenPercentile p-valueAdjusted Score p-valuePercentile Grip Strength (pounds) Dominant hand 43.3 ± 13.9 64.2 ± 26.4 47.5 ± 9.5 28.2 ± 18.1 0.08 <0.001 Nondominant hand 43.9 ± 11.8 65.4 ± 24.6 46.1 ± 8.4 25.2 ± 17.5 0.29 <0.001 CKD stage 3bAdjusted Score CKD stage 3bPercentile CKD stage 4Adjusted Score CKD stage 4 Percentile p-valueAdjusted Score p-valuePercentile Grip Strength (pounds) Dominant hand 46.5 ± 11.3 49.4 ± 29.5 43.0 ± 13.5 42.1 ± 29.4 0.16 0.23 Nondominant hand 45.5 ± 10.4 47.7 ± 28.8 43.9 ± 10.3 42.9 ± 30.6 0.45 0.44 Mean (SD) Adjusted score: adjusted for age, sex, race/ethnicity and education level