P196 Predictors of fracture in patients with primary hyperparathyroidism

Abstract

Abstract Background Primary hyperparathyroidism (PHPT) is a recognised risk factor for fractures as the persistently elevated parathyroid hormone levels are associated with lower bone mineral density (BMD). In early osteoporosis (<65 years), there is mainly trabecular bone loss while with increasing age, the largest loss of absolute bone mass occurs in cortical sites. Our aim was to compare cortical versus trabecular bone sites to determine which sites better predict fracture in PHPT patients referred for dual-energy X-ray absorptiometry (DEXA) scan in an observational cohort. Methods 508 patients with PHPT referred for DEXA scan at Royal Lancaster Infirmary (UK) between 2006-2016 were included in a retrospective data analysis. Data collected included femoral and lumbar BMD, age, gender, height, weight, BMI, rheumatoid arthritis, smoking, alcohol, family history of fractures, secondary osteoporosis and long-term steroid use and was used to look at predictors of fractures using BMD at different sites. Simple statistics using independent t-tests and chi-squared tests were initially used and subsequently, logistic models were fitted unadjusted and adjusted confounding variables. Results 97 males (19%) and 411 females (81%) were included, with 111 patients sustaining at least one fracture (21.9%). Mean age was 65 years (SD 0.55). Advanced age, female gender and a reduced BMD were all statistically significant factors associated with an increased risk of fractures. Smoking and long-term steroid use were also shown to increase risk of fracture however these were non-statistically significant. Adjusting for age and gender, a reduced L4 BMD was the strongest statistically significant predictor of fracture (OR 0.139, 95% CI: 0.112-0.782). Multivariate analysis revealed that a reduced L3 BMD was the strongest statistically significant predictor of fracture (OR 0.170, 95% CI: 0.071-0.72). Conclusion Overall, our study suggests that a reduced BMD at trabecular sites is a stronger predictor of fracture compared to cortical sites [Table 1]. Older age and female gender significantly increased the risk of fracture in PHPT patients. To the best of our knowledge, this is the first study looking at specific bone sites as independent predictors of fracture in PHPT patients. This analysis should be repeated using a larger cohort to validate our results. Disclosures D. Mariannis None. M. Bukhari None.