The association between grip strength and kidney stones: A National Health and Nutrition Examination Survey and...

The formation of kidney stones is influenced by multiple factors, including physical health indicators such as grip strength (GS), which reflects overall muscle health. This study aimed to investigate the relationship between GS and the risk of developing kidney stones.

Data from the National Health and Nutrition Examination Survey between 2011 and 2014 were analyzed. The maximum value of six GS measurements was selected as the definitive value. Relative grip strength (rGS) was calculated to adjust for body size differences. Chi-square tests and t-tests were employed for categorical and continuous variables, respectively. Logistic regression models were used to evaluate the relationships of GS and rGS with the prevalence of kidney stones. Two-sample Mendelian randomization using the inverse-variance weighted method verified the causal association.

The study included 9306 participants, with 302 having kidney stones. Participants with kidney stones had lower mean GS (32.0 kg vs. 37.3 kg, p<0.001) and rGS (1.12 vs. 1.34, p<0.001). Logistic regression showed that higher GS and rGS (divided into quartiles Q1-Q4) were associated with a reduced risk of kidney stones (GS: Q4 vs. Q1, odds ratio 0.32, 95% confidence interval 0.20-0.51, p<0.001; rGS: Q4 vs. Q1, odds ratio 0.45, 95% confidence interval 0.28-0.71, p<0.001). Two-sample Mendelian randomization results confirmed a negative association between right-hand GS and the risk of kidney stones.

Lower GS is linked to a higher risk of kidney stones, highlighting the importance of muscle health in the prevention of kidney stones.