Association of handgrip strength and CT-derived body composition with insulin resistance in women with prediabetes and newly diagnosed type 2 diabetes.

OBJECTIVE: To examine the associations of handgrip strength and CT-derived muscle and visceral fat indices with insulin resistance in middle-aged women with prediabetes and newly diagnosed type 2 diabetes. SUBJECTS AND METHODS: This cross-sectional study included 44 women aged 40-60 years attending a tertiary endocrinology clinic. Participants were classified according to the American Diabetes Association (ADA, 2022) criteria as having prediabetes (n = 29) or newly diagnosed type 2 diabetes (n = 15). All participants underwent anthropometric assessment, biochemical testing, L3-level CT imaging for visceral adipose tissue (VAT) and psoas muscle measurements, and handgrip strength evaluation using a digital dynamometer. Insulin resistance was assessed using the homeostatic model assessment for insulin resistance (HOMA-IR). Multivariable linear regression analysis was performed to identify independent factors associated with HOMA-IR. RESULTS: Dominant-hand grip strength demonstrated an inverse association with HOMA-IR (β = -0.297, p = 0.033). VAT volume and BMI were not significantly associated with HOMA-IR after adjustment (p > 0.75). The overall model explained 28% of the variance in HOMA-IR (R2 = 0.28; adjusted R2 = 0.14). Psoas muscle thickness showed a borderline inverse relationship with HOMA-IR (p = 0.079). CONCLUSION: In this cohort of women with early glucose dysregulation, handgrip strength was independently associated with insulin resistance, whereas visceral adiposity was not. These findings suggest that muscle performance may represent a clinically relevant correlation of early metabolic impairment. Longitudinal studies are needed to clarify the temporal relationships.