Diabetes and Its Complications and Their Relationship with Risk of Fractures in Type 1 and 2 Diabetes

This case-control study sought to assess the effects of diabetes and its complications on the risk of fractures. There were 124,655 fracture cases and 373,962 age- and sex-matched controls. The main exposure was diabetes and its complications, and the main confounders were use of insulin and oral antidiabetic agents, presence of cardiovascular disease, and use of drugs for cardiovascular disease, along with a number of other confounders. In the crude analysis, diabetes and all complications was associated with a statistically significantly increased overall risk of fractures. The increase in risk of fractures was higher in type 1 diabetes (T1D) than in type 2 diabetes (T2D). However, after adjustment for confounders, the difference between T1D and T2D disappeared, and only diabetic kidney disease in T1D retained a significantly increased risk of fractures. There was a time dependency in the risk of fractures with an early increase at <2.5 years after diagnosis. followed by a decrease to the level of the background population from 2.5 to 5 years after diagnosis, and a limited increase in T1D but not T2D at >5 years after diagnosis. We conclude that diabetes, whether T1D or T2D, seems to carry an increased risk of fractures, and complications to diabetes except for diabetic kidney disease add little to the overall risk of fracture, perhaps pointing at a common risk factor linked to the high blood glucose levels, which may weaken bone strength.