Body composition in adults with newly diagnosed type 2 diabetes: effects of metformin

BACKGROUND: The aim of this study was to measure the body composition in adults with newly diagnosed type 2 diabetes mellitus and to explore the effect of metformin therapy on the various components of body composition, insulin sensitivity, and glucose homeostasis. METHODS: This was an observational study consisted of 51 newly diagnosed people with type 2 diabetes on 1000 mg metformin twice daily for 6 months. The body composition of each subject was measured by dual energy X-ray absorptiometry at enrollment and 24 weeks after metformin mono-therapy. Sarcopenia was defined and compared based on the ratio of appendicular skeletal muscle and height squared, skeletal muscle index and residual methods. Homeostasis model assessment-insulin resistance and Quantitative Insulin Sensitivity Check Index were used for estimating insulin sensitivity. The level of physical activity was assessed using self-administered International physical Activity questionnaire. RESULTS: Forty one subjects (80.4%) completed the study. The mean age of the participants was 52.67 ± 10.43 years. Metformin treatment was associated with a significant decrease in total fat mass (−1.6 kg, P = 0.000). By week 24, the lean to fat ratio increased (P = 0.04) with men showing greater significant changes. Twenty percent of the female participants were detected to have sarcopenia. In addition, there was a significant improvement of glucose homeostasis and insulin sensitivity. CONCLUSIONS: Metformin therapy results in significant improvement in body composition and insulin sensitivity of adults with newly diagnosed type 2 diabetes. Furthermore, sarcopenia begins in women with diabetes much earlier than expected as an age related phenomenon.