Assessment of fracture risk by the FRAX algorithm in men and women with and without type 2 diabetes mellitus: a cross-sectional study.

Background: The FRAX algorithm is a diffuse tool to assess fracture risk, but it has not been clinically applied in European patients with diabetes. We investigated FRAX-estimated fracture risk in patients with type 2 diabetes mellitus (DM), compared with concomitantly enrolled control subjects.

Methods: In our multicentric cross-sectional study, we assessed the FRAX scores of 974 DM and 777 control subjects from three Italian diabetes outpatient clinics, and in DM. We tested the association between parameters and complications of the disease and FRAX scores.

Results: DM had significantly lower FRAX-estimated probability of both major osteoporotic fracture (MOF) and hip fracture (HF) than control subjects (6.35 ± 5.07% versus 7.75 ± 6.93%, p < 0.001, and 2.17 ± 3.07% versus 2.91 ± 4.56%, p = 0.023, respectively). When grouping by gender, such differences were found only in men. In DM, the frequency of previous fracture was higher than in control subjects (29.88% versus 20.46%, p < 0.001). In diabetic patients, age, sex, body mass index, HbA1c and hypoglycaemia are significantly associated with FRAX scores; gender-specific regression models differed. Among DM, the tree-based regression (classification and regression tree (CART)) analysis identified groups of patients with different mean FRAX scores. In female DM aged > 65 years with or without obesity, MOF > 20% was found in 5.66% and 13.53% and H  > 3% in 40.57% and 63.91% of patients, respectively.

Conclusions: Patients with DM had mean FRAX scores lower than control subjects, despite the higher number of previous fractures. Some features and complications of DM did associate with FRAX scores. Among DM patients, the CART analysis identified subgroups with higher FRAX scores. However, despite its potential utility, concerns still remain for using FRAX in DM patients.