Individual and combined effects of muscle strength and visceral adiposity on incident prediabetes and type 2 diabetes in a longitudinal cohort of midlife Asian women

Aim: To investigate the independent and combined effects of muscle strength and visceral adiposity on prediabetes and type 2 diabetes incidence among midlife women. Materials and Methods: In this prospective study of midlife women (mean age 56.4 years), visceral adiposity, defined as visceral adipose tissue (VAT) >131 cm2 measured by dual energy X-ray absorptiometry, and poor combined muscle strength, defined as handgrip strength <18 kg and/or five-time repeated chair stand test performance >= 12 s, were determined at baseline between 2014 and 2016. After 6.6 years, the effects of VAT and muscle strength on risk of incident prediabetes (fasting blood glucose 5.6-6.9 mmol/L) and type 2 diabetes (fasting blood glucose levels >= 7 mmol/L, medication use, or physician diagnosis) were examined using modified Poisson regression analysis. Results: Among the 733 initially normoglycaemic participants, 150 (20.5%) developed prediabetes or type 2 diabetes. Women with both poor combined muscle strength and high VAT had the highest risk for both prediabetes and type 2 diabetes (adjusted relative risk [aRR] 2.63, 95% confidence interval [CI] 1.81-3.82). In comparison, high VAT alone increased risk by 1.78-fold (95% CI 1.12-2.84). Stratification analyses showed that among women with low muscle strength, high VAT demonstrated increased risks of prediabetes and type 2 diabetes (aRR 2.84, 95% CI 1.95-4.14) compared to those with normal strength (aRR 1.66, 95% CI 1.04-2.65). Conclusions: Low combined muscle strength with high VAT poses a greater risk for the development of prediabetes and type 2 diabetes than high VAT alone. Muscle strengthening should be promoted alongside weight loss in diabetes prevention.