Association between diabetes of different durations and hip fracture in middle-aged and older people: a stratified cohort study from CHARLS 2011-2020

Background The effect of the duration of diabetes on hip fracture is inconsistent. The aim of this study was to analyze the association between different durations of diabetes and hip fracture. Methods This cohort study included participants from the China Health and Retirement Longitudinal Study (CHARLS) 2011-2020. Diabetes was defined as glycated hemoglobin A1c >= 6.5%, fasting blood glucose >= 126 mg/dL, random blood glucose >= 200 mg/dL, or previous diagnosis of diabetes. Participants were stratified according to diabetes duration, and information was collected on their first hip fracture. The association between diabetes of different durations and hip fracture was assessed using Cox proportional risk models and Kaplan-Meier curves. Results A total of 9,927 participants with a mean age of 58.4 +/- 8.7 and 54.3% female were included, and 574 participants suffered a hip fracture. Compared with no diabetes, the associations between overall diabetes, newly diagnosed diabetes, diabetes with a duration of < 6 years, and hip fracture were all not significant, all P > 0.05. Known diabetes and diabetes of duration >= 6 years significantly increased the risk of hip fracture, with hazard ratios (HRs) and 95% confidence intervals (CIs) of 1.69 (1.19 similar to 2.4), P = 0.003, and 2.2 (1.34 similar to 3.61), P = 0.002. Conclusions Neither newly diagnosed diabetes nor diabetes with a disease duration of < 6 years was associated with hip fracture compared with no diabetes people. When the duration of diabetes is >= 6 years, the risk of hip fracture is significantly increased, and appropriate preventive measures are recommended.