Elevated Hip Fracture Risk in Type 1 Diabetic Patients

Elevated Hip Fracture Risk in Type 1 Diabetic Patients A Population-Based Cohort Study in Sweden Junmei Miao , MD, MSC 1 , Kerstin Brismar , MD, PHD 2 , Olof Nyrén , MD, PHD 1 , Anna Ugarph-Morawski , MD 2 and Weimin Ye , MD, PHD 1 1 Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden 2 Department of Molecular Medicine, Karolinska Hospital, Stockholm, Sweden Address correspondence and reprint requests to Weimin Ye, MD, PhD, Assistant Professor, Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Box 281, SE 171 77, Stockholm, Sweden. E-mail: weimin.ye{at}meb.ki.se Abstract OBJECTIVE —Patients with type 1 diabetes often have low bone mineral density, but epidemiological data on fracture risk are sparse and imprecise, particularly for men. RESEARCH DESIGN AND METHODS —In the Swedish Inpatient Register, we identified a population-based cohort of 24,605 patients (12,551 men and 12,054 women) who were hospitalized for diabetes before age 31 years during 1975 through 1998. Follow-up for hip fracture was accomplished through cross-linkage in the Inpatient Register until the end of 1998. Censoring information was obtained from the registers of Death and Migration. Using the Kaplan-Meier method, we calculated the cumulative probability of getting a hip fracture. Standardized hospitalization ratios and their 95% CIs estimated relative risks with the age-, sex-, and calendar period–matched Swedish general population as reference. RESULTS —In total, 70 and 51 first hip fractures were ascertained in men and women, respectively, corresponding to a cumulative probability (both sexes) of 65.8/1,000 until age 65 years. Markedly elevated risks were observed in both men and women (standardized hospitalization ratios = 7.6 [95% CI 5.9–9.6] and 9.8 [7.3–12.9], respectively), increasing with follow-up time. Ophthalmic, nephropathic, neurological, and cardiovascular complications were indicators of particularly high risks. CONCLUSIONS —Both male and female type 1 diabetic patients are at increased risk for hip fracture. Although optimal preventive measures still need to be defined, the co-occurrence with other diabetes complications suggests that tighter metabolic control might reduce the risk. SHR, standardized hospitalization ratio Footnotes A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances. Accepted September 11, 2005. Received J