OBJECTIVE To investigate trends in incidence rates (IRs) at various fracture sites for patients with type 1 diabetes and type 2 diabetes compared with patients without diabetes in Denmark in 1997–2017. RESEARCH DESIGN AND METHODS Patients aged ≥18 years with a vertebral, hip, humerus, forearm, foot, or ankle fracture between 1997 and 2017 were identified from Danish hospital discharge data. IRs per 10,000 person-years were calculated over the study period. Median IRs for the first (1997–2001) and the last (2013–2017) 5 years were compared. We used Poisson models to estimate age-adjusted IR ratios (IRRs) of fractures among patients with type 1 and type 2 diabetes versus patients without diabetes. RESULTS Except for foot fractures, fracture IRs were higher in patients with type 1 or type 2 diabetes compared with patients without diabetes. Hip fracture IRs declined between the first and last 5 years by 35.2%, 47.0%, and 23.4% among patients with type 1, type 2, and without diabetes, respectively. By contrast, vertebral fracture IRs increased 14.8%, 18.5%, 38.9%, respectively. While age-adjusted IRRs remained elevated in patients with type 1 diabetes compared with patients without diabetes, IRRs in patients with type 2 diabetes converged with those observed in patients without diabetes. CONCLUSIONS Unadjusted fracture rates are higher in patients with diabetes but have decreased between 1997 and 2017 except for vertebral fractures, which increased in all groups. Fracture rates change after age adjustment.

Context Bone turnover markers (BTMs) are lower in type 2 diabetes (T2D). The relationships between bone turnover, β-cell function, and insulin sensitivity in T2D are uncertain. Objective To investigate if fasting levels of BTMs in persons with T2D are associated with β-cell function or insulin sensitivity. Methods We defined three T2D phenotypes: the insulinopenic (low β-cell function, high insulin sensitivity), the classical (low β-cell function, low insulin sensitivity) and the hyperinsulinemic (high β-cell function, low insulin sensitivity) phenotypes, in the Danish Centre for Strategic Research in T2D cohort, using the homeostatic assessment model. We selected age and gender matched subgroups to represent the three T2D phenotypes, yielding 326 glucose-lowering treatment naïve persons with T2D. Median values of BTMs between the three T2D phenotypes were compared. Regression models were applied to assess the association between BTMs, β-cell function and insulin sensitivity, adjusted for potential confounders. Results Median serum levels of procollagen type I N-terminal propeptide, C-terminal telopeptide of type I collagen and osteocalcin were higher in the insulinopenic phenotype (52.3 (μg/L) IQR [41.6, 63.3], 259.4 (ng/L) [163.4, 347.7], 18.0 (μg/L) [14.4, 25.2], respectively) compared to the classical (41.4 [31.0, 51.4], 150.4 [103.5, 265.1], 13.1 [10.0, 17.6], respectively) and the hyperinsulinemic (43.7 [32.3, 57.3], 163.3 [98.9, 273.1], 15.7 [10.2, 20.8], respectively) phenotypes (all p < 0.01). These differences persisted after adjustment for age, sex, waist-to-hip ratio, or fasting plasma glucose (p < 0.01). Conclusion BTMs are lower in newly diagnosed persons with T2D characterized by low insulin sensitivity.