Investigating the risk of bone fractures in elderly patients with type 2 diabetes mellitus: a retrospective study

BACKGROUND: Elderly patients with type 2 diabetes mellitus (T2DM) experience fractures more frequently than elderly individuals without diabetes. Fractures requiring hospitalization greatly affect quality of life, and although elderly patients with T2DM have several risk factors associated with fractures, only a few studies have evaluated these in detail in the Asian population. We conducted a retrospective study of elderly patients with T2DM for evaluating factors associated with fracture risk. METHODS: We conducted a retrospective study using electronic medical records (EMR) of patients aged ≥65 years with T2DM who were admitted to a public general medical institute in central Tokyo, Japan. We evaluated factors associated with fractures necessitating hospitalization in elderly patients with T2DM characteristics and hypoglycemic agent use. Factors associated with fracture risk were identified using multivariable logistic regression analysis. RESULTS: A total of 2,112 elderly patients (age ≥ 65 years) with T2DM were analyzed. Among them, 69 (3.3%) patients had been hospitalized for fractures. Factors associated with fractures were female sex (OR, 3.46), eGFR < 60 ml / min / 1.73 m(2) (OR, 0.55), and thiazolidine use (OR, 4.28). Further, a separate analysis based on sex revealed that the use of thiazolidines was significantly associated with fracture risk in both sexes. CONCLUSIONS: In elderly patients with T2DM, the key factor associated with fractures was the use of thiazolidines in both males and females. In this study, the use of thiazolidines was newly identified as a factor which increased the risk of fractures requiring hospitalization in elderly males. The study findings should be considered when hypoglycemic agents are selected for treating elderly patients with T2DM. Information bias, selection bias, and the effect of concomitant drugs may be the underlying reasons for why eGFR < 60 mL / min / 1.73 m(2) reduced the fracture risk. However, details are unknown, and additional investigations are needed.