8749 Skeletal effects among pre and postmenopausal women with hypoparathyroidism (HypoPT); data from the Canadian National Hypoparathyroidism Registry (CNHR)

Abstract Disclosure: H. AbuAlrob: None. S. Hussein: None. H. Afifi: None. D.S. Ali: None. A. Almoulia: None. D. Bole: None. M. Braga: None. P. Chandra: None. A. Cheng: None. R. Cheung: None. J.E. Young: None. J. Hetal: None. S. Khan: None. T.S. Khan: None. J. Malhem: None. H. Malik: None. S. Mehmood: None. A. Millar: None. E. Morgante: None. F. Naveed: None. H. Niazi: None. T.L. Paul: None. A. Prebtani: None. Z. Punthakee: None. J.A. Shaban: None. R. Shah: None. M. Shrayyef: None. M. Shaikh: None. C. Tagra: None. S.R. Teschke: None. I.T. Tauqir: None. S. Van Uum: None. W. Robert: None. M. Ovize: Employee; Self; Amolyt. A.A. Khan: Research Investigator; Self; Amolyt, Ascend Therapeutics (A Besins Healthcare company), Takeda. Introduction: the CNHR registry was established in 2014 with the objectives of identifying the etiology, presentation, natural history and current treatment of hypoPT[1]. Methods: 101 patients with hypoPT were included in this prospective study. Patients completed baseline assessments including 3 site bone mineral density (BMD), trabecular bone score (TBS), fracture risk assessments, and bone biomarkers. Baseline data is presented. Results: A total of 101 participants were enrolled, 83 (82%) were female, and 18 (18%) were male. There were 35 (42%) premenopausal females and 48 (58%) postmenopausal females (PMF). Only PMF were on antiresorptive therapy. Seven (7/8) were on bisphosphonate therapy (i.e., alendronate), and 3 females were on denosumab. Among premenopausal females the average corrected calcium (Ca) was 2.03 mmol/L (SD=0.26), calcium phosphate product (Ca PO4) was 2.75 (SD=0.62), and the eGFR 94.63 mL/min (SD=18.08). The average bone turnover markers among premenopausal women for the Telopeptide-C (CTX) was 242.4 ng/L (SD=209.4) (CTX within the reference range (WRR) 136-689 ng/L) while the Propeptide 1 Collagen (P1NP) was 37.6 ug/L (SD=39.2) (P1NP WRR 19-83 ug/L). Among PMF, the average corrected Ca was 2.22 mmol/L (SD=0.18), Ca PO4 was 2.14 (SD=0.17), and the eGFR 73.9 mL/min (SD=23.0). The average bone turnover markers among PMF for CTX was 346.1 ng/L (SD=488.4) (WRR 177-1015 ng/L) while P1NP was 47.1 ug/L (SD=33.1) (WRR 16-98 ug/L). Among premenopausal women (n=35), the mean total hip Z-score was 0.87 (SD=1.29), L1-L4 Z-score 0.98 (SD=1.19), FN Z-score 0.59(SD=1.17), and 1/3R Z-score -0.04 (SD=0.77). Among PMF (n=48) the mean total hip T-score was -0.20 (SD=1.65), L1-L4 T-score -0.24 (SD=1.88), FN T-score -0.43(SD=1.59), and 1/3R T-score -0.94(SD=1.23).TBS scores in premenopausal women were normal (TBS=1.41 (SD=0.10)) however the TBS was partially degraded among PMF (TBS= 1.28(SD=0.15)). Fracture data has previously been reported3. Conclusion: The effects of hypoPT on bone strength needs further study2. Our data suggests that bone quality maybe impaired in PMF with hypoPT as noted by the presence of degraded TBS scores and the presence of fragility fracture in this population. Reference 1.Khan AA et al Canadian national hypoparathyroidism registry: an overview of hypoparathyroidism in Canada. Endocrine 2021. 2.Khan AA et al JBMR 2022 Evaluation and Management of Hypoparathyroidism Summary Statement and Guidelines from the Second International Workshop3.Hussein S et al. Skeletal effects of hypoparathyroidism (HypoPT); data from the Canadian National Hypoparathyroidism Registry (CNHR). Available here: https://amolytpharma.com/wp-content/uploads/2023/10/ASBMR-CNHR_FINAL.pdf Presentation: 6/2/2024