Sarcopenia is increasingly recognized as a prevalent and underdiagnosed complication among patients with type 2 diabetes mellitus (T2DM), leading to greater risk of falls, disability, hospitalization, and mortality. Handgrip strength (HGS), a simple and validated proxy for global muscle function, is a useful early indicator of sarcopenia. However, the multifactorial determinants of HGS decline in T2DM, particularly involving abdominal obesity and renal dysfunction, remain incompletely understood in Asian populations. Our aim is to investigate the independent predictors of HGS decline in patients with T2DM, with a focus on waist-to-height ratio (WHtR), renal function, and their interactions across different BMI categories.

This retrospective cross-sectional study included 1,468 adult T2DM patients who underwent HGS measurement at Kaohsiung Chang Gung Memorial Hospital. Clinical data were retrieved from electronic health records and outpatient databases, encompassing demographic, anthropometric, biochemical, behavioral, and comorbidity profiles. Univariate and multivariate logistic regression analyses were conducted to identify independent factors associated with declined HGS. Subgroup analyses explored the joint effects of BMI and WHtR on muscle strength.

Participants with declined HGS were significantly older and had longer diabetes duration, lower BMI, higher WHtR (>0.5), higher urinary albumin-to-creatinine ratio (Ln-ACR), and a higher prevalence of advanced chronic kidney disease (CKD stage ≥3). In multivariate models, WHtR >0.5 (adjusted OR 1.809; p = 0.002), Ln-ACR (adjusted OR 1.127; p = 0.003), and advanced CKD (adjusted OR 1.834; p = 0.002) remained independent predictors of HGS decline, while BMI ≥24 was inversely associated (adjusted OR 0.516; p < 0.001). Subgroup analysis showed that patients with BMI <24 and WHtR ≥0.5 had the highest risk of muscle weakness (OR = 1.90; p = 0.002).

Abdominal obesity and renal dysfunction are independent and complementary risk factors for HGS decline in patients with T2DM. WHtR >0.5 identifies high-risk individuals even in those with normal BMI, underscoring its clinical utility as a practical screening tool in Asian populations. Routine assessment of WHtR and renal markers may enhance early detection of sarcopenia risk and guide targeted interventions in diabetes care.