Utility of diffusion tensor imaging for assessing bone quality in type 2 diabetes: correlation with bone turnover biomarkers.

We examined type 2 diabetic patients by diffusion tensor imaging, an advanced magnetic resonance technique, and found significant differences than healthy subjects that correlated with markers of bone turnover. This could help in assessment of bone quality in diabetics where bone density often appears normal despite high fracture risk. INTRODUCTION: Type 2 diabetes (T2DM) induced bone fragility is mainly due to alteration of bone quality rather than a decline in bone mineral density. The aim of the present study was to assess the ability of diffusion tensor imaging (DTI) to assess bone quality in T2DM. METHODS: A total of 68 patients with T2DM were enrolled and stratified into two groups: those with microvascular complications (n = 38) and those without (n = 30). Additionally, 30 age- and sex-matched healthy controls were included. All participants underwent DTI of the lumbosacral spines and both hips, dual-energy X-ray absorptiometry (DEXA) scanning, and assessment of bone turnover biomarkers, including C-terminal telopeptide of type I collagen (CTX) and procollagen type I N-terminal propeptide (P1NP). RESULTS: DTI parameters-fractional anisotropy (FA) and apparent diffusion coefficient (ADC)-differed between patients and controls. FA values for the spine and hips were lower, while ADC values for the hips were higher in both diabetic patient groups compared to control subjects. ADC values for the spine were higher in diabetic patients with complications than in controls. A significant positive correlation was observed between FA and CTX levels in patients with complications. No significant differences were found in DEXA scan results between patients and controls. FA and ADC values for the hips showed the highest area under the curve (AUC) values (0.868 and 0.818, respectively), followed by FA and ADC for the spine (0.779 and 0.721), according to ROC curve analysis. The optimal cutoffs yielding the best sensitivity and specificity were observed for FA over ADC. CONCLUSION: DTI can provide information about the microstructural changes associated with the development of a low bone turnover state in type 2 diabetes mellitus, where bone mineral density typically remains within the normal range.