Increased risks of hip fracture in diabetic patients of Taiwan

OBJECTIVE - Using Taiwan's National Health Insurance claim data, we evaluated the age-, sex-, and urbanization-specific incidence density and relative risks of hip fracture in the diabetic population. RESEARCH DESIGN AND METHODS - Diabetic patients (n = 500,868) and an age-and sex-matched control group (n = 500,248) were linked to inpatient claims (1997-2002) to identify hospitalizations for nontransport accident hip fracture. The person-year approach with Poisson assumption and Kaplan-Meier analysis were used to estimate the incidence and the cumulative event rates. We also assessed the age-, sex-, and urbanization-specific relative risks of hip fracture in relation to diabetes with the Cox proportional hazard regression model. RESULTS - The overall incidences of hip fracture for diabetic men and women, respectively, were 3.01 and 6.75/1,000 person-years, which were higher than those for control men and women. There were significant interactions of diabetes and age and diabetes and urbanization statuses. Hazard ratios (HRs) of diabetic patients aged 35-44 years (men 2.45 [95% CI 1.65-3.64]; women 3.19 [1.39-7.33]) were higher than those of diabetic patients aged 55-64 years (men 1.90; women 2.81), but in diabetic men aged > 74 years and diabetic women aged > 84 years, the HRs were compared with null statistically (HRs 0.98 and 0.91, respectively). Diabetic patients living in rural areas tended to have higher HRs of hip fracture. CONCLUSIONS - In Taiwan, diabetes increased the risk of hip fracture in both sexes in all age-groups except in diabetic men aged > 74 years and diabetic women aged > 84 years. Higher HRs of hip fracture were disproportionately observed in younger diabetic patients and in those living in rural areas.