Epidemiology and correlates of osteoporotic fractures among type 2 diabetic patients.

This study analyzed data on 87,224 osteoporotic patients with up to 18 years of computerized medical history. Patients with osteoporosis and type 2 diabetes had higher bone density yet more fractures than non-diabetic osteoporotic patients. Fracture incidence among the diabetic patients was associated with retinopathy and cardiovascular disease, but not with diabetes duration.

PURPOSE: Little is known about the association between type 2 diabetes mellitus (T2DM) and fragility fractures or the mechanism(s) involved. We examined fracture correlates among T2DM patients with osteoporosis.

METHODS: We used electronic health records of an osteoporosis (OP) registry cross-linked with a diabetes registry of a large payer provider healthcare organization in Israel. A cross-sectional analysis compared osteoporosis patients with and without T2DM, and a longitudinal Cox proportional hazard regression was used to identify incident fracture correlates.

RESULTS: As of December 2015 a total of 87,224 current OP patients were identified, of whom 15,700 (18%) had T2DM. The T2DM OP patients were characterized by older age (mean 74.6 vs. 69.5), more males (20.3 vs. 14.0%), and a higher rate of chronic comorbidities compared to OP without diabetes. All major OP fractures (hip, spine, humerus, and forearm) were significantly more prevalent among T2DM OP patients (44 vs. 32%), with an overall age-standardized ratio of 1.22 (95% CI 1.19 to 1.25) and 1.15 (95% CI 1.10 to 1.21) for females and males respectively. The average T-scores were higher (femur neck - 1.8 vs. - 1.9, total hip - 1.2 vs. - 1.6, and vertebrae - 1.3 vs. - 1.7) for the T2DM OP patients compared to the non-T2DM OP patients. Among women with coexisting T2DM and osteoporosis (n = 10,812), fracture incidence was significantly associated with retinopathy (HR = 1.24, 95% CI 1.05 to 1.47) and cardiovascular disease (HR = 1.22, 95% CI 1.10 to 1.36) after controlling for age, bone mineral density T-score, rheumatoid arthritis, glucocorticoids, alcohol, and smoking).

CONCLUSION: This large population-based study confirms the higher fracture risk of osteoporotic patients with T2DM, as compared to osteoporotic patients without T2DM, despite higher bone mineral density levels. The presence of micro- and macrovascular disease appears to increase this risk.