Thiazolidinediones and Their Effect on Bone Metabolism: A Review

Thiazolidinediones (TZDs) are a class of antihyperglycemic agents commonly used in the treatment of type 2 diabetes mellitus. It is accepted that through activation of peroxisome proliferator-activated receptor (PPAR) gamma, TZDs have an effect on bone metabolism. People with diabetes are already at an increased risk of fractures due to multiple factors, but recent incidental findings in A Diabetes Outcome Progression Trial (ADOPT) have introduced the idea that TZD use may increase fracture risk in women. This review article will summarize the current evidence regarding the effect of TZDs on bone metabolism in vitro and in animal and human studies, with an emphasis on their effects on bone mineral density and changes in bone turnover markers. The available but limited evidence investigating the relationship between TZD use and fracture risk will also be addressed.