Relative Handgrip Strength and Lower-Body Fat-Free Mass Are More Strongly Associated with Diabetes Mellitus than Absolute Strength and Total Fat-Free Mass: A KNHANES 2022-2023 Study

This study examines whether handgrip strength (absolute handgrip strength [AHGS] or relative to body weight handgrip strength [RHGS]) and total and lower-body fat-free mass (FFM) are associated with the prevalence of diabetes mellitus (DM) and compares the relative explanatory value of these indices overall and by sex. METHODS:We analyzed 4,767 adults (men: 2,319; women: 2,448) from the 2022-2023 Korea National Health and Nutrition Examination Survey.AHGS was the maximum value from four trials; RHGS was AHGS divided by body weight.Total and lower-body FFM were obtained via bioelectrical impedance analysis (InBody 970).DM was defined as fasting glucose 126 mg/dL, HbA1c 6.5%, or physician diagnosis/treatment.Each exposure was categorized into sex-specific tertiles.Logistic regression estimated odds ratios (ORs) and 95% confidence intervals (CIs).RESULTS: Model 1 was adjusted for sex, age, height, education, income, marital status, and occupation; Model 2 was additionally adjusted for smoking status, alcohol consumption, and weekly physical activity.Compared with the lowest RHGS tertile (T1: 42.66%), the highest tertile (T3: 53.26%) showed 61% lower odds of DM (95% CI: 0.28-0.53).For lower-body FFM, T3 (15.32kg) versus T1 (12.10 kg) was associated with 43% lower odds (95% CI: 0.33-0.99).Among men, participants in the highest RHGS tertile (T3: 59.62%) had 58% lower odds of DM compared with those in the lowest tertile (T1: 50.77%) (95% CI: 0.30-0.59).Among women, the highest RHGS tertile (T3: 45.65%) was associated with 45% lower odds compared with the lowest tertile (T1: 38.34%) (95% CI: 0.37-0.82),and the highest lower-body FFM tertile (T3: 12.30kg) was associated with 64% lower odds compared with the lowest tertile (T1: 10.87 kg) (95% CI: 0.18-0.70). CONCLUSIONS:Relative handgrip strength and lower-body fat-free mass were more consistently associated with lower odds of diabetes mellitus than absolute strength and total fat-free mass.