Effect of oral hypoglycaemic agents on bone metabolism in patients with type 2 diabetes mellitus

Diabetes mellitus (DM) and osteoporosis are the two important public health problems in India. The burden of both these conditions is expected to increase in the near future in view of changing lifestyle habits and ageing population. Indians are at risk of osteoporosis due to their low body mass index (BMI), genetic predisposition and nutritional factors. The diseases type 1 DM and type 2 DM (T2DM) are associated with increased fracture risk in the disease population, in spite of difference in the bone mineral density (BMD). An increase in fracture risk is also reported among older patients with T2DM despite frequently reported normal or increased BMD. Administration of insulin stimulates osteoblast activity and bone mineral apposition rates. The impact of endogenous insulin production, insulin sensitivity, and exogenous insulin administration as an anabolic agent for bone in T2DM has not been clarified. Biguanides and sulphonylureas do not appear to have adverse effects on BMD. Preclinical evidence suggests that incretin-based drugs may be beneficial for bone, but clinical evidence to support this hypothesis is not yet available. Thiazolidinedione (TZD) group of agents have been implicated in causing osteoporosis in various animal studies and some human studies available till date. The debate regarding this is issue is still ongoing. Randomized controlled studies with larger sample size preferably involving multiple centres, multiple ethnicities are required to answer these queries.