Association of glycemic coefficient of variation with reduced appendicular skeletal muscle mass index among patients with type 2 diabetes mellitus: a cross‑sectional study

Objective The coefficient of variation (CV) of glycemia, calculated from continuous glucose monitoring (CGM) data, quantifies intraday glycemic variability. However, its association with reduced appendicular skeletal muscle mass in patients with type 2 diabetes mellitus (T2DM) remains unclear. This study aimed to investigate the association between glycemic CV and reduced ASMI. Methods This retrospective cross-sectional study enrolled 1453 hospitalized T2DM patients aged ≥18 years who required intensive insulin pump therapy. Baseline clinical and laboratory data were collected, and glycemic CV was computed from CGM records. ASMI was measured using bioelectrical impedance analysis. Participants were categorized into the reduced ASMI group (n = 341) and normal muscle mass group (n = 1112) according to ASMI values, and further stratified by quartiles of glycemic CV. Multivariable logistic regression was performed to examine the independent association between glycemic CV and reduced ASMI. Restricted cubic spline (RCS) models were constructed to characterize the shape of this association. Subgroup analyses and multiple sensitivity analyses were conducted to verify the robustness of findings. Results Glycemic CV was significantly higher in participants with reduced ASMI. In the fully adjusted multivariable model, elevated glycemic CV was independently associated with increased odds of reduced ASMI (OR = 1.17, 95% CI: 1.04–1.31, P = 0.008). RCS analysis indicated a statistically significant overall association, with no statistically significant nonlinearity (P = 0.148). Subgroup analyses revealed no significant interactions across strata of age, diabetes duration, gender, HbA1c, and visceral fat area. Sensitivity analysis demonstrated that the association between glycemic CV and reduced ASMI disappeared after additional adjustment for BMI (OR = 0.96, 95% CI: 0.52–1.82, P = 0.902), suggesting that the association was sensitive to adjustment for BMI. Conclusions In hospitalized patients with type 2 diabetes receiving intensive insulin pump therapy, elevated glycemic variability was associated with reduced ASMI in the primary model; however, this association was no longer statistically significant after additional adjustment for BMI, indicating that the association was sensitive to adjustment for BMI. Intra-day glycemic variability may provide clues for exploring the mechanisms underlying skeletal muscle mass maintenance in this population.