Continuous glucose monitoring-derived glycemic variability and low skeletal muscle mass in middle-aged and older adults with type 2 diabetes mellitus: an analysis using AWGS 2025 criteria.

BACKGROUND

The impact of glycemic variability (GV) on muscle mass in type 2 diabetes mellitus (T2DM) remains unclear under the updated Asian Working Group for Sarcopenia (AWGS) 2025 criteria. We investigated the association between continuous glucose monitoring (CGM)-derived GV and low skeletal muscle mass (LSMM).

METHODS

This cross-sectional study included 614 hospitalized T2DM patients aged ≥ 50 years. GV metrics (SD, MODD, LAGE, and CV) were derived from 7-day CGM data. LSMM was identified using bioelectrical impedance analysis based on age-specific AWGS 2025 thresholds. Multivariate logistic regression, restricted cubic splines (RCS), subgroup, and mediation analyses were performed.

RESULTS

Patients with LSMM exhibited significantly higher GV. In fully adjusted models, higher SD (OR = 1.36), MODD (OR = 1.38), and LAGE (OR = 1.08) were independently associated with increased LSMM risk (all p < 0.05). RCS analysis revealed a linear dose-response relationship between GV and LSMM. Subgroup analyses demonstrated consistent associations across BMI, eGFR, sex, age and HbA1c categories (all p for interaction > 0.05). Mediation analysis indicated that insulin sensitivity-related indices (HOMA2-IR) partially mediated the GV-LSMM relationship.

CONCLUSIONS

Elevated GV is independently associated with LSMM in middle-aged and older adults with T2DM, showing a linear dose-response pattern consistent across diverse clinical profiles. Strategies targeting glucose fluctuations may be crucial for preserving muscle mass in this population.