Based on HbA1c Analysis: Bone Mineral Density and Osteoporosis Risk in Postmenopausal Female with T2DM

Introduction: This study aims to investigate association between glycosylated hemoglobin (HbA1c) with bone mineral density (BMD) and osteoporosis-risk in postmenopausal female with type 2 diabetes mellitus (T2DM). Methodology: HbA1c values, BMD of L3 vertebra and basic clinical data of 152 postmenopausal females with T2DM and 326 postmenopausal females without T2DM were retrospectively analyzed. The propensity score matching was used to match the T2DM and the non-T2DM group at a ratio of 1:1. Restricted cubic spline (RCS) analysis and piecewise linear regression were used to evaluate the relationship between HbA1c and BMD. Univariable and multivariable logistic regression were utilized to evaluate the effect of HbA1c on the risk of osteoporosis in matched diabetes population. Results: After matching, the BMD (66.60 (46.58, 93.23) vs. 63.50 (36.70, 83.33), P < 0.05), HbA1c value (7.50 (6.72, 8.80) vs 5.30 (5.14, 5.50), P  <  0.05) in the T2DM group were significantly higher than that of non-T2DM group. We found a nonlinear relation between HbA1c value and BMD, which showing a U-shaped curve with the cutoff value around 7.5 % (P_overall < 0.001, P_nonliearity < 0.05). The prevalence of osteoporosis in T2DM group was similar to that in controls (64.9 % vs 73.6 %, P = 0.102). Age-adjusted HbA1c value was not risk factor of osteoporosis in postmenopausal females with T2DM. Conclusion: In postmenopausal females with T2DM, high BMD and similar risk of osteoporosis were confirmed; HbA1c was a contributing factor to BMD when values exceed 7.5 %. However, HbA1c does not seem to be associated with osteoporosis risk.