Parathyroid hormone, aldosterone-to-renin ratio and fibroblast growth factor-23 as determinants of nocturnal blood pressure in primary hyperparathyroidism: The eplerenone in primary hyperparathyroidism trial

Objectives: The high prevalence of arterial hypertension in primary hyperparathyroidism (pHPT) is largely unexplained. Apart from parathyroid hormone (PTH), the mineral hormones fibroblast growth factor (FGF)-23 and aldosterone-to-renin ratio (ARR) are upregulated in pHPT. We aimed to determine whether nocturnal blood pressure (BP) is related with PTH, FGF-23 or ARR in a relatively large sample of pHPT patients. Methods: Cross-sectional data of the single-center \u2018\u2018Eplerenone in Primary Hyperparathyroidism\u2019\u2019 trial were used. All patients with a biochemical diagnosis of pHPT who had both available 24-h ambulatory BP monitoring and valid laboratory data were included. Results: Full data were available in 136 patients (mean age 6710 years, 78% women). Median PTH was 99 (interquartile range: 82\u2013124) pg/ml and mean calcium was 2.630.15mmol/l. ARR, but not PTH or FGF-23, was significantly and directly related with nocturnal SBP (Pearson\u2019s r\ubc0.241, P<0.01) and DBP (r\ubc0.328, P<0.01). In multivariate regression analyses, with adjustment for age, sex, PTH, FGF-23, traditional cardiovascular risk factors, antihypertensive medication and parameters of calcium metabolism ARR remained significantly and directly related with nocturnal BP (SBP: adjusted b-coefficient\ubc0.289, P<0.01; DBP: b\ubc0.399, P