Abstract 15844: Plasma Parathyroid Hormone is Independently Related to 24-Hour Pulse Wave Velocity in Patients With Primary Hyperparathyroidism - Insights fFom The EPATH Study

Abstract

Introduction: Accumulating evidence indicated that high parathyroid hormone (PTH) is associated with increased cardiovascular risk. The impact of PTH on vascular structure and function is, however, still unclear. We evaluated the relationship between pulse wave velocity (PWV) as a novel index of arterial stiffness and circulating levels of PTH in patients with PTH-excess (primary hyperparathyroidism (pHPT)). Methods and Results: We analyzed baseline data of the ongoing randomized, double-blind, placebo-controlled “Effect of Eplerenone on Parathyroid Hormone Levels in Patients with Primary Hyperparathyroidism” (EPATH) study. Inclusion criteria were age of at least 18 years and a diagnosis of pHPT according to international guidelines. Standardized blood sampling was performed after an overnight fast and 24h PWV was measured by a validated non-invasive device for ambulatory hemodynamic monitoring (Mobil O Graph, I.E.M., Stolberg, Germany). Our analysis comprised 92 pHPT patients with a mean age of 68.5 +/- 9.7 years (71 % females) and a median PTH of 102 (IQR 81 - 132) pg/ml. Mean 24h PWV was 9.8 +/- 1.8 m/s, mean daytime and mean nighttime PWV were 10.0 +/- 1.7 m/s and 9.6 +/- 1.8 m/s, respectively. In multivariate linear regression analyses adjusted for age, sex, body mass index, smoking status, mean systolic and mean diastolic 24h blood pressure, antihypertensive medication, type 2 diabetes, 25-hydroxyvitamin D, serum calcium, intake of cinacalcet and fasting serum cholesterol PTH emerged as a strong predictor of mean 24h PWV (ß=0.30, p=0.012), daytime PWV and nighttime PWV (ß=0.30, p=0.011 and ß=0.30, p=0.019, respectively). Conclusion: In a selective cohort of patients with pHPT plasma PTH was strongly related to 24h PWV. These data strengthen the notion that PTH may impact on vascular function. Interventional and mechanistic trials are needed to evaluate modulatory effects on vasculature in patients with high PTH.