LAUSR

Frailty is a known risk factor for chronic disease and mortality. However, the association between frailty assessed by hand grip strength (HGS) and chronic kidney disease (CKD) among adults has not been elucidated. This study evaluated the association between muscle strength and the risk of CKD. Data were retrieved from a nationwide cohort study (Korean National Health and Nutrition Examination Surveys VI-VII, 2014-2017) and participants aged 40 to 80 years were included in the study analysis (male=6,660, female=8,195). HGS was measured using digital hand dynamometer and normalized to body mass index (BMI). The association between the risk of CKD (estimated glomerular filtration rate [eGFR] <60 mL/min/1.73 m2 or the presence of proteinuria) and quartile of HGS per BMI was evaluated among male and female subjects. The mean age was 58.8 ± 11.6 years and mean eGFR level was 88.2 ± 18.7 mL/min/1.73 m2. The mean levels of HGS per BMI were 1.5 ± 0.3 and 0.9 ± 0.2 in male and female subjects, respectively. Those in higher quartile of HGS per BMI showed lower prevalences of advanced CKD stages than lowest quartile among both male and female subjects. When univariable logistic regression analysis for the risk of CKD was performed, higher quartile of HGS per BMI was significantly associated with lower risk of CKD in both male and female subjects. After adjustment for confounding factors including age, systolic blood pressure, smoking and alcohol intake, education and income levels, history of hypertension, diabetes, or arthritis, physical activity, baseline eGFR, total cholesterol, hemoglobin, and daily protein intake, the higher quartile of HGS per BMI were associated with lower risk of CKD in both male and female subjects (odds ratio [OR], 0.66; 95% confidence interval [CI], 0.49-0.88 in Q4; OR, 0.64; 95% CI 0.49-0.83 in Q3 in male; OR, 0.59; 95% CI, 0.43-0.81 in Q4; OR, 0.61; 95% CI, 0.47-0.80 in Q3; OR, 0.70;95% CI, 0.55-0.90 in Q2 in female, Q1 as reference group). These associations were consistent when the HGS per BMI was treated as continuous variable that 34% and 54% of risk was reduced as 1 m2 increase in male and female subjects. Greater muscle strength normalized to BMI is associated with lower risk of CKD in adults. These findings suggest that frailty in adults is an important risk factor for CKD development.