Sex-specific associations between grip strength and metabolic syndrome in Korean adults: a nationally representative cross-sectional study

Objective This study examined whether the association between grip strength and metabolic syndrome differs by sex and how it is influenced by body mass index (BMI). Methods We analyzed nationally representative cross-sectional data from Korean adults aged ≥40 years who participated in the 2022–2024 Korea National Health and Nutrition Examination Survey. Grip strength was categorized into sex-specific tertiles. Metabolic syndrome was defined according to modified ATP III criteria using Korean-specific waist circumference thresholds. Survey-weighted logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) using sequential adjustment models. Results In men, the association between grip strength and metabolic syndrome observed in minimally adjusted models was markedly attenuated after BMI adjustment. In women, low grip strength was associated with higher odds of metabolic syndrome, and this association became stronger after BMI adjustment. Compared with women in the highest tertile, those in the lowest tertile had higher odds of metabolic syndrome (OR 1.54, 95% CI 1.21, 1.96). A significant interaction between grip strength and sex was observed. Conclusions BMI substantially influenced the association between grip strength and metabolic syndrome, particularly in men. Grip strength may provide additional information on metabolic risk beyond BMI, especially among women.