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

UNLABELLED: 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.