PAPER DETAILS

Context
Diabetes mellitus (DM) is associated with an increased risk of fractures. However, the impact of glycemic control on the risk of fracture is not well understood.

Objective
To evaluate the association between the level of glycemic control and the risk of low-trauma fractures in patients with type 1 (T1DM) and type 2 (T2DM) diabetes mellitus.

Design
Nested case-control analysis.

Setting
UK-based Clinical Practice Research Datalink.

Patients or other participants
The study population consisted of patients whose T1DM or T2DM was newly diagnosed between 1995 and 2015. Cases were patients with a low-trauma fracture after DM onset. We matched 4 controls to each case on age, sex, general practice, fracture date, and diabetes type and duration.

Statistical analysis
Conditional logistic regression analyses adjusted for covariates including BMI, smoking, diabetes complications and medications.

Results
The study population consisted of 3,329 T1DM and 44,275 T2DM patients. Median duration between diabetes onset and fracture date was 4.5 years for both, T1DM and T2DM. The risk of fracture was increased in T1DM patients with mean HbA1c >8.0% (aOR 1.39, 95% CI 1.06-1.83) compared to T1DM patients with mean HbA1c values ≤7.0%. There was no such effect in T2DM patients. Independently of glycemic control, the risk of fracture was elevated in patients with T2DM and current use of rosiglitazone and pioglitazone.

Conclusions
The impact of glycemic control on the risk of low-trauma fracture differs between T1DM and T2DM patients. Poor glycemic control increased the risk of fracture in T1DM but not in T2DM patients.