SUN-LB68 Advanced Glycation Endproducts Are Associated With Worse Bone Material Strength in Older Adults With and Without Type 2 Diabetes

Abstract

Patients with Type 2 Diabetes (T2D) are at increased fracture risk despite having relatively normal or even increased BMD by DXA. The critical aspect of bone quality deterioration in T2D patients could explain this clinically important discrepancy. Material composition is a component of bone quality that has emerged as a potential factor contributing to fragility fractures in T2D patients. However, there is sparse evidence regarding whether T2D patients have decreased bone material properties compared with non-diabetic controls. We hypothesized that increased production of advanced glycation endproducts (AGEs) has an important role in reducing bone material strength in patients with and without diabetes. Thus, we used the OsteoProbe®, a bone microindentation device that provides an index of cortical bone material properties (Bone Material Strength index – BMSi) in men with T2D age ≥ 50 yrs or postmenopausal women with T2D and nondiabetic controls. We also utilized a non-invasive measure of skin AGEs (AGE Reader®) to evaluate AGEs accumulation through skin autofluorescence. Linear regression models were used to assess group differences with and without adjusting for age, Body Mass Index (BMI), and sex. Relationships between variables were assessed using adjusted Pearson correlations. A total of 152 T2D patients (mean age 68.5 ±7.6 yrs.; 59.2% men; HbA1C=7.7 ±1.0%; mean diabetes duration 15.5 yrs.) and 105 non-diabetic controls (mean age 67.2±8.8 yrs.; 41.0% men; HbA1C =5.4 ±0.3%) were recruited to the study. Overall, there was no difference in BMSi between T2DM and control subjects: unadjusted (p= 0.636); adjusted (p= 0.695). However, skin AGEs were negatively correlated with BMSi (r= -0.23, p <0.001). In subgroup analyses, skin AGEs were also negatively associated with BMSi in both T2DM (r= -0.23, p=0.004) and control (r= -0.21, p=0.033) subjects. In conclusion, these findings demonstrate that a higher burden of AGEs is associated with worse bone quality. Our findings may explain the conflicting findings regarding reductions in BMSi in T2D because only T2D patients with a high level of AGEs accumulation have impaired BMSi. Moreover, the association of skin AGEs with BMSi in non-diabetic subjects emphasizes the important role of AGEs in decreasing bone quality and potentially contributing to fracture risk. Collectively, our data indicate that non-invasive skin AGEs measurement could be used as a tool to evaluate bone quality in patients with T2D as well as in the non-diabetic population.