Fractures in type 2 diabetes confer excess mortality: The Dubbo osteoporosis epidemiology study

Abstract

Purpose: Diabetes and fractures are both associated with increased mortality, however the effect of the combination is not well-established. We examined the mortality risk following all types of fractures in type 2 diabetes (T2D).

Methods: In the Dubbo Osteoporosis Epidemiology Study (1989-2017), participants were grouped according to T2D and/or incident fracture. Study outcome was all-cause mortality. First incident radiological fragility fracture and incident T2D diagnosis were time-dependent variables. Cox's proportional hazards models quantified mortality risk associated with T2D and incident fracture overall, as well as by fracture site, T2D duration and T2D medication type.

Results: In 3618 participants (62% women), 272 had baseline and 179 developed T2D over median 13.0 years (IQR 8.2-19.6). 796 women (56 with T2D) and 240 men (25 with T2D) sustained a fracture. Compared to those without T2D or fracture, mortality risk increased progressively, in T2D without fracture, then no T2D with fracture, and was highest in those with T2D with fracture (adjusted hazard ratio (aHR) (95% CI) for women 2.62 (1.75-3.93) and men 2.61 (1.42-4.81)). Within T2D participants, incident fracture was associated with increased mortality (aHR for women 1.87 (1.10-3.16) and men 2.83 (1.41-5.68)), especially following hip/vertebral fractures in men (aHR 2.97 (1.29-6.83)) and non-hip non-vertebral fractures in women (aHR 2.42 (1.24-4.75)), and in T2D duration >5 years.

Conclusion: Any fracture in T2D conferred significant excess mortality. Individuals with T2D should be carefully monitored post-fracture, especially if T2D >5 years. Optimising fracture prevention and post-fracture management in T2D is critical and warrants further studies.

Keywords: Bone; Diabetes; Fractures; Mortality; Osteoporosis.