8312 Predictors of Mortality in Primary Hyperparathyroidism: Long-Term Follow Up

Abstract Disclosure: F.W. Gibb: None. J.R. Seckl: None. L. Reid: None. M.J. Lyall: None. Background: Primary hyperparathyroidism has been associated with an increased risk of death and cardiovascular disease in observational studies. We have previously published associations between PTH concentration (and other potential explanatory variables) and mortality risk and now present results based on longer follow up duration. Methods: Retrospective cohort study of individuals (n = 611) presenting with PHPT between 2006 and 2014 to a University teaching hospital. Predictors of mortality were assessed by the Cox proportional hazard model. Results: Median age was 68 years (IQR 58 – 77) and 503/611 (82%) were female. Parathyroid surgery was performed in 274 (45%). Median duration of follow up was 12 years over which time 38% of the cohort died (n = 230). Results are subsequently presented for the total cohort and the subgroup (n = 337, 55%) who did not have parathyroid surgery. Total cohort Higher age at diagnosis (HR 1.09 per year, p <0.001), lower BMI (HR 0.97 per kg/m2, p = 0.037), greater socioeconomic deprivation (HR 0.6 for least deprived quintile, p = 0.01), higher serum creatinine (HR 1.01 per μM, p <0.001) and vitamin D deficiency (HR 1.58, p = 0.005) were all associated with mortality in univariate analysis. Adjusted calcium (HR 1.5 per mM, p = 0.101) and PTH at diagnosis (HR 1.002 per pM, p = 0.415) were not significantly associated with subsequent mortality. However, in a multivariate model, adjusted calcium was independently associated with mortality (HR 9.0 per mM, p < 0.001) whilst higher PTH was associated with a lower risk of death (HR 0.98 per pM, p = 0.012). No surgery cohort Adjusted calcium (HR 13.3 per mM, p < 0.001), PTH (HR 1.04 per pM, p <0.001), higher age at diagnosis (HR 1.07 per year, p <0.001), lower BMI (HR 0.96 per kg/m2, p = 0.012) and vitamin D deficiency (HR 1.4, p = 0.047) were all associated with mortality in univariate analysis. Socioeconomic deprivation (p = 0.218) and creatinine (p = 0.105) were not associated with mortality in the non-surgical subgroup. In multivariate analysis, higher age (p <0.001), higher adjusted calcium (p <0.001), lower BMI (p = 0.025) and socioeconomic deprivation (p = 0.049) were all independently associated with mortality but PTH was not (p = 0.745). Conclusions PTH concentration does not appear to be independently associated with mortality risk in people with PHPT. Plasma calcium concentration appears to be a more important association but can be affected by many factors which are independent of PHPT (e.g. concomitant medications, hydration status, delay in seeking medical attention etc.) Presentation: 6/2/2024