Abstract 98: Effect of teriparatide, zolendronate or denosumab on HR-Pqct parameters in postmenopausal women with T2DM at high risk of fragility fractures: intrim analysis of an open label RCT

Background: There is an increased risk of fragility fractures in patients with type 2 diabetes mellitus (T2DM). Bone mineral density (BMD) as measured by DEXAmay be increased despite poor quality of bone and thus FRAX may underestimate the risk of fractures in this population. HR-pQCT is a non-invasive imaging modality for assessment of volumetric BMD (vBMD) and microarchitecture of cancellous and cortical bones. Also the available data regarding the choice of anti-osteoporotic therapy in T2DM are based on either preclinical studies or posthoc/subgroup analysis of randomized controlled trials (RCTs) with no head-to-head comparison. We aim to compare the efficacy of the three most commonly used anti-osteoporotic medications, namely, teriparatide, zoledronate and denosumab, in a cohort of postmenopausal women with T2DM at a high risk of incident fragility fractures. Methods: Here we present the interim analysis after 6 months of an open-labelled randomised control trial of 120 postmenopausal women with T2DM enrolled for 18 months follow-up. Patients were randomised into 4 groups in 1:1:1:1 ratio, with group Areceiving teriparatide, group B receiving zoledronate, Group C receiving denosumab each along with calcium and vitamin D supplements and group D receiving only calcium and vitamin D supplements. The objective was to determine the effects of the anti-osteoporotic drugs on HR-pQCT parameters at the end of 6 months compared to at the time of enrolment. Results: 31 patients who completed their 6 months follow-up were included in the analysis, 8 in group A, 7 in group B and D and 9 in group C. There were no significant change in the vBMD amongst the groups at 6 months at both tibia (p = 0.075) and radius (p = 0.067). There was a decrease in the total vBMD in all the 4 groups at tibia. However at the radius, total vBMD increased in group B and decreased in the rest, however the intra-group changes were not significant. There was a statistically significant difference in trabecular spacing at tibia between group A (increased) and group C (decreased) (p = 0.031). There were no significant changes in other bone microarchitecture parameters. Conclusion: At the end of 6 months, there were no significant changes in volumetric BMD and bone microarchitecture at both tibia and radius amongst the groups except for trabecular spacing. Larger number of patients with longer follow-up would help in further understanding.