Renin-angiotensin-aldosterone and endothelin-1 systems in primary hyperparathyroidism associated with arterial hypertension

Aim of the study was to investigate the role of renin-angiotensin-aldosterone system (RAAS) and endothelin-1 (ET-1) in the pathogenesis of arterial hypertension in primary hyperparathyroidism (PHP). Methods. We studied 44 PHP patients (37 females, 7 males; mean age 55±13 yrs) divided into 2 groups: 25 (57%) normotensive and 19 (43%) hypertensive patients; 25 healthy subjects (NS: 13 males, 12 females; mean age 48±10 yrs) and 32 patients with essential hypertension (EH: 18 female, 14 males; mean age 52±11 yrs). In all groups we measured calcium-phosphorus metabolism and plasma renin activity (PRA), aldosterone (PAC) and ET-1 concentrations. Results. Results did not demonstrate significant differences in mineral metabolism parameters (Ca, Ca++, P, creatinine, ALP, iPTH) between normotensive and hypertensive PHP patients. In hypertensive PHP patients positive correlation between plasma iPTH and systolic (S) (r=0.517; p=0.023) and diastolic (D) blood pressure (BP) (r=0.586, p<0.001) and heart rate (HR), (r=0.485, p=0.043) was found. In hypertensive PHP patients PRA and PAC concentrations were significantly higher than in NS and normotensive PHP patients. Positive correlation in hypertensive PHP between iPTH and PRA (r=0.566, p=0.009) and PAC (r=0.684, p<0.001) was also found. No significant correlation was seen in normotensive PHP patients. In PHP patients with arterial hypertension, plasma ET-1 levels were significantly higher than in NS, normotensive PHP and EH patients. In these patients iPTH and ET-1 concentrations (r=0.554, p<0.019) were positively correlated as well as ET-1 and DBP (r=0.456, p<0.05). Conclusions. These results seem to indicate a pathogenetic role of renin-angiotensin-aldosterone system and endothelin-1 in hypertensive PHP patients.