Effect of diabetes on BMD and TBS values as determinants of bone health in the elderly : Bushehr Elderly health program

Background: Considering the aging population associated with higher osteoporotic fracture risk, high prevalence of diabetes and its effect on bone health along with lack of information on bone quality using common methods (BMD) the aim of present study was to determine the association between trabecular bone score (TBS) and diabetes in an elderly population participating in Bushehr Elderly Health (BEH) program. Materials and methods: This cross-sectional study was performed on data collected during the BEH Program, stage II. Anthropometric indices were measured based on NHANES III protocol. Diabetes and pre-diabetes were defined according to ADA Guideline 2018. Bone density was measured using DXA method (DXA, Discovery WI, Hologic Inc., USA). A software installed on the same device (TBS iNsight® software) was applied to assess TBS values. Variables related to bone health were compared based on their glycemic status (participants with diabetes, participants with prediabetes, and normoglycemic) using analysis of variance. Univariate and multivariate linear and logistic regression models were used to determine the association between TBS values and bone density in different glycemic states. Results: The data of 2263 participant aged 60 years and over were analyzed. Mean TBS values were significantly different between participants with diabetes, participants with prediabetes, and normoglycemic groups (P = 0.004;, however, P trend was not significant (0.400)). Mean BMD values at femoral neck and lumbar spine were significantly higher in diabetics compared with those diagnosed with pre-diabetes; the latter also had higher bone density compared with normoglycemic individuals (both P ANOVA test and P trends for means were < 0.01]. In univariate linear regression model, TBS values were negatively associated with pre-diabetes (β = −0.070; P < 0.001) but not with diabetes (β = −0.002, P = 0.915). This significant relationship disappeared when the results were adjusted for BMI. In fully adjusted multivariate logistic regression models, odds ratio linking pre-diabetes and diabetes with spinal osteoporosis was 0.861 (CI 95% 0.670–1.105) and 0.525 (CI 95% 0.392–0.701), respectively. As for femoral osteoporosis, odds ratio was 0.615 (CI 95% 0.407–0.928) and 0.968 (CI 95% 0.629–1.489), correspondingly. Moreover, for cumulative osteoporosis, the odds were 0.843 (CI 95% 0.676–1.106) and 0.551 (CI 95% 0.415–0.732), respectively. Conclusion: Our findings suggest that subjects with pre-diabetes and diabetes have higher bone mineral density than normoglycemic subjects; the quality of bone, however, was not different between them. The discordance between BMD and TBS values in participants with diabetes suggest that although these patients have higher BMD values, their quality of bone microarchitecture may not be better than normoglycemic subjects