Diabetes Mellitus and the Risk of Fracture

Cho, Dong Hyeok; Chung, Jin Ook; Chung, Min Young; Chung, Dong Jin

Abstract

The bone mass is known to be decreased in patients with type 1 diabetes, and this is primarily due to osteoblastic dysfunction. A number of epidemiologic studies have consistently shown a significantly higher risk of fractures in type 1 diabetic patients as compared to that of healthy subjects. The data on bone mineral density (BMD) in patients with type 2 diabetes has been inconsistent. However, many recent epidemiologic studies have shown that the osteoporotic fracture risk, and especially at the hip, is also increased in patients with type 2 diabetes, and even in patients with normal or higher BMD. Meanwhile, several studies have shown higher bone mass and a lower fracture risk in subjects with recent onset type 2 diabetes or impaired glucose tolerance with hyperinsulinemia. Poor bone quality and an increased risk of falling are thought to be important contributing factors for the higher fracture risk in patients with type 2 diabetes. Collagen overglycosylation by accumulation of advanced glycation end products (AGE) is thought to be one of the possible mechanisms underlying poor bone quality. The risk of falling in patients with diabetes is increased due to hypoglycemia, visual impairment from retinopathy and cataracts, altered balance, gait problems due to neuropathy and foot ulcers, associated cardiovascular diseases and medication use. Insulin-sensitizing agents, such as thiazolidinediones, are also associated with a higher fracture risk through an increase in bone marrow adiposity and a decrease in osteoblastogenesis. Because diabetes and osteoporosis are highly prevalent chronic diseases in the aging population and the incidences are increasing worldwide, understanding the risk factors that predispose patients to such conditions is very important. On considering the potential mechanisms associated with bone metabolism, adequate glycemic control while minimizing the episodes of hypoglycemia is the most important first step in the medical management to prevent osteoporotic fractures in patients with diabetes.