Association between relative handgrip strength and insulin resistance using the triglyceride-glucose index in adults without diabetes: a cross-sectional study in Korea

Low handgrip strength is associated with increased insulin resistance (IR). However, few studies have comprehensively examined the association between handgrip strength and IR among Korean adults without diabetes. This study aimed to investigate the association between relative handgrip strength and IR and to identify factors associated with IR by age group and sex using nationally representative data from Korean adults without diabetes. This cross-sectional study included 2,929 adults who participated in the 2022 Korea National Health and Nutrition Examination Survey. Relative handgrip strength was defined as the mean of two measurements obtained from the dominant hand divided by body mass index (BMI). IR was estimated using the triglyceride-glucose (TyG) index. Relative handgrip strength was categorised into quartiles, with the highest quartile (Q4) as the reference group. Participants in the upper quartile of the TyG index were classified as having high IR. Multivariate logistic regression analyses were performed, and subgroup analyses were stratified by age group and sex. In the total sample, the adjusted odds ratios (aORs) for high IR were 1.659 (95% confidence interval [CI]: 1.065–2.586), 1.540 (95% CI: 1.088–2.180), and 1.368 (95% CI: 1.012–1.849) in Q1, Q2, and Q3, respectively. In the age-stratified analyses, this pattern was most pronounced among middle-aged adults (40–64 years), with aORs (95% CI) for high IR of 3.727 (1.789–7.764), 2.469 (1.350–4.515), and 1.683 (1.070–2.646) in Q1, Q2, and Q3, respectively, compared to Q4. Sex-stratified analyses were consistent with the overall findings. Abdominal obesity, smoking, and muscle-strengthening exercise were identified as modifiable factors for IR. Low relative handgrip strength was associated with high IR in Korean adults without diabetes, particularly among middle-aged adults (40–64 years). Relative handgrip strength may be a useful indicator of insulin resistance risk. Targeted strategies to reduce abdominal obesity, promote smoking cessation, and encourage muscle-strengthening exercise may help prevent insulin resistance. Not applicable