The skeletal effects of thiazolidinedione and metformin on insulin-resistant mice.

To explore the skeletal effects and the potential underlying mechanisms of treatment with two thiazolidinediones (rosiglitazone and pioglitazone) or metformin in insulin-resistant mice, 24 female, 12-week-old C57BL6J ob/ob mice were evaluated according to the following treatment groups for 6 weeks: placebo group, pioglitazone group (Pio), rosiglitazone group (Rosi), and metformin group (Met). Bone mineral density (BMD), bone microarchitecture, bone histomorphometry, and expression of three phenotype-specific gene markers, including bone morphogenetic protein 2 (Bmp2), runt-related transcription factor 2 (Runx2), and fatty acid-binding protein 4 (Fabp4), were compared across the four groups. At the femur, the Met group had the highest BMD (0.