ABSTRACT
OBJECTIVES: To determine whether tight glycemic control is associated with greater risk of hip fractures in individuals being treated for type 2 diabetes mellitus. DESIGN: Case-control study. SETTING: Tertiary hospital. PARTICIPANTS: Cases were selected from all individuals with diabetes mellitus admitted between 2005 and 2010 to Changi General Hospital for hip fracture (N = 932). Cases were included if their glycosylated hemoglobin (HbA1c) had been measured within 3 months of the fracture and they were undergoing treatment with oral hypoglycemic medications or insulin. Each case was matched with one control for sex, age, race, duration of diabetes mellitus, and comorbidities. MEASUREMENTS: Information on baseline characteristics, HbA1c, and use of diabetic medications was obtained. The likelihood of hip fracture was determined comparing four different values of HbA1c [<6%, 6.1-7.0%, 7.1-8.0%, >8% (reference group)] and use of diabetic medications. RESULTS: The mean age of cases was 77.3 ± 7.7, and 73.3% were female. After adjusting for age, sex, race, comorbidities, and other covariates, participants with tighter glycemic control (HbA1c < 6% and 6.1-7.0%) were more likely to have a hip fracture than those with HbA1c >8% (odds ratio (OR) = 3.01, 95% confidence interval (CI) = 2.01-4.51, P < .001; and OR = 2.34, 95% CI=1.71-3.22, P < .001, respectively). The use of insulin and sulfonylurea was similar between cases and controls. CONCLUSION: The present study found an association between tight glycemic control (when HbA1c < 7%) and greater risk of hip fracture in individuals being treated for type 2 diabetes mellitus. Greater caution needs to be exercised in treating older patients with diabetes mellitus.
