Abstract P036: Parathyroid Hormone is Associated with All-Cause and Cardiovascular Mortality: The Hoorn Study

Introduction Higher parathyroid hormone (PTH) concentrations have been associated with increased cardiovascular disease (CVD) mortality, although data in the general population are scarce. Hypothesis We hypothesize that higher serum PTH concentrations are associated with all-cause and CVD mortality in a prospective, population-based cohort of older men and women. Methods We included 633 participants of the Hoorn Study, a population-based cohort with oversampling of subjects with impaired glucose regulation; mean age 70.1±6.6 years, 50.7% female. Serum intact PTH concentrations were measured using a 2-site immunoassay. Outcomes were all-cause and CVD mortality based on clinical files and coded according to the ICD-9. We used Cox-regression to estimate survival curves and hazard ratios (HR 95% CI) for all-cause and CVD mortality adjusted for potential confounders using season-specific PTH quartiles. Results During a median follow-up of 7.8 years, 112 participants died, of which 26 deaths (23%) were due to CVD. Survival curves showed an impaired survival for all-cause (Log-rank p=0.054) and CVD mortality (Log-rank p=0.022) for people in the highest PTH quartile (Figure 1). In a multivariate model adjusted for age, sex, smoking, education level, BMI, glucose status, systolic blood pressure, anti-hypertensive drug use, the highest PTH quartile was associated with higher all-cause mortality; HR 1.98 (1.08, 3.64). Kidney function (estimated glomerular filtration rate and micro-albuminuria) attenuated the PTH risk association, but risk persisted; HR 1.93 (95% CI 1.04, 3.58). The results for CVD mortality showed a similar pattern, although the association was only significant in a threshold model (Quartile 4 vs. Quartile 1-3) HR 2.56 (1.11, 5.94). Conclusion In conclusion, among older men and women, higher PTH concentrations are associated with higher mortality risk. We suggest to evaluate whether individuals with high PTH concentrations benefit from therapeutic approaches targeted to decrease PTH concentrations.