Metformin in Elderly Patients With Type 2 Diabetes and Muscle Strength, Muscle Mass, and Physical Function: Positive or Negative Correlation?

This study aimed to explore the association between long-term use of metformin and muscle strength, muscle mass, and physical function, providing a basis for rational use of glucose-lowering drugs in elderly patients with Type 2 diabetes. A total of 290 elderly patients were enrolled. Patients were screened using propensity score matching, resulting in 132 matched individuals, 66 in the metformin group (Group A) and 66 in the nonmetformin group (Group B). Group comparisons assessed the correlation between metformin and muscle strength, muscle mass, and physical function, with further stratification by glycated hemoglobin (HbA1c). Statistical methods included t-tests, nonparametric tests, chi-square tests, and logistic regression analyses. Results obtained are as follows: (1) The difference in the proportion of low grip strength between Groups A and B was statistically significant (48.5% vs. 19.7%, p < 0.001). (2) In HbA1c-stratified analysis, when 7.8% ≤ HbA1c < 9.4%, Groups A and B showed statistically significant differences in skeletal muscle mass (17.2 ± 3.0 vs. 19.9 ± 4.5 kg, p = 0.049), relative skeletal muscle mass (6.5 ± 0.8 vs. 7.2 ± 1.1 kg/m2, p = 0.03), proportion of low grip strength (57.1% vs. 13.6%, p = 0.013), and proportion of low gait speed (71.4% vs. 40.9%, p = 0.039); when HbA1c ≥ 9.4%, significant difference in proportion of low grip strength (41.2% vs. 5.9%, p = 0.033) was observed between groups. This study found that long-term metformin use in elderly patients with Type 2 diabetes is positively associated with a higher proportion of low grip strength. Particularly in patients with poor glycemic control, metformin constitutes an unfavorable factor for sarcopenia. Trial Registration: ClinicalTrials.gov identifier: NCT07788378.