The assessment of trabecular bone score to improve the sensitivity of FRAX in patients with type 2 diabetes mellitus
Aim. To estimate the trabecular bone score (TBS) for evaluation of fracture probability in order to make decisions about starting osteoporosis treatment in patients with type 2 diabetes mellitus (T2DM). Materials and methods. We obtained the bone mineral density (BMD) and trabecular bone score (TBS) using dual energy X-ray absorptiometry (iDXA) in patients with T2DM (with and without a history of osteoporotic fractures) versus the control group. Before and after TBS measurements we assessed the ten-year probability of fracture using the Fracture Risk Assessment Tool (FRAX). Results. We enrolled 48 patients with T2DM, including 17 with a history of low-traumatic fracture, 31 patients without fractures and 29 subjects of a control group. BMD was higher in patients with T2DM compared to the control group at L1-L4 (mean T-score 0.44, 95% CI -3.2 - 4.9 vs mean T-score 0.33, 95% CI -2.9 - 3.0 in a control group p=0.052) and Total Hip (mean T-score 0.51, 95% CI -2.1 - 3.0 vs mean T-score -0.03, 95% CI -1.4 - 1.2 in a control group p=0,025). The TBS and 10-year probability of fracture (FRAX) was not different in patients with T2DM versus the control group. However, when the TBS was entered as an additional risk factor, the 10-year probability of fracture became higher in patients with T2DM (10-year probability of fracture in T2DM- 8.68, 95% CI 0.3-25.0 versus 6.68, 95% CI 0.4-15.0 in control group, p=0.04). Among patients with diabetes with and without fractures the FRAX score was higher in subjects with fractures, but no difference was found in regards to BMD or TBS. Entering BMD and TBS values into the FRAX tool in subjects with diabetes and fractures decreased the FRAX score. However, patients with low-traumatic fractures should be treated for osteoporosis without a BMD, TBS or FRAX assessment. Conclusion. TBS improves the results of FRAX assessment in patients with T2DM and should be entered while evaluating FRAX in patients with T2DM. However, additional research is needed to develop a more sensitive tool to evaluate fracture risk in patients with T2DM.