Sitagliptin and risk of fractures in type 2 diabetes: Results from the TECOS trial

Aim: To examine fracture incidence among participants in the Trial Evaluating Cardiovascular Outcomes with Sitagliptin (TECOS). Research design and methods: We used data from 14 671 participants in the TECOS study who were randomized double-blind to sitagliptin (n = 7332) or placebo (n = 7339). Cumulative fracture incidence rates were calculated and their association with study treatment assignment was examined using multivariable Cox proportional hazards regression. Results: The baseline mean (standard deviation) participant age was 65.5 (8.0) years, diabetes duration was 11.6 (8.1) years and glycated haemoglobin level was 7.2 (0.5)% [55.2 (5.5) mmol/mol], and 29.3% of participants were women and 32.1% were non-white. During 43 222 person-years’ follow-up, 375 (2.6%; 8.7 per 1000 person-years) had a fracture; 146 were major osteoporotic fractures (hip, n = 34; upper extremity, n = 81; and clinical spine, n = 31). Adjusted analyses showed fracture risk increased independently with older age (P <.001), female sex (P <.001), white race (P <.001), lower diastolic blood pressure (P <.001) and diabetic neuropathy (P =.003). Sitagliptin, compared with placebo, was not associated with a higher fracture risk [189 vs 186 incident fractures: unadjusted hazard ratio (HR) 1.01, 95% confidence interval (CI) 0.82 to 1.23, P =.944; adjusted HR 1.03, P =.745], major osteoporotic fractures (P =.673) or hip fractures (P =.761). Insulin therapy was associated with a higher fracture risk (HR 1.40, 95% CI 1.02-1.91; P =.035), and metformin with a lower risk (HR 0.76, 95% CI 0.59-0.98; P =.035). Conclusion: Fractures were common among people with diabetes in the TECOS study, but were not related to sitagliptin therapy. Insulin and metformin treatment were associated with higher and lower fracture risks, respectively.