1. ¹Department of Clinical Science, University of Rome 'La Sapienza', Rome, Italy
2. ²Day Hospital of Internal Medicine and Arterial Hypertension, University of Rome 'La Sapienza', Rome, Italy

Correspondence: Professor C Letizia, Department of Clinical Science, Policlinico Umberto I, Viale del Policlinico 155, 00156 Rome, Italy. E-mail: claudio.letizia@uniroma1.it

Received 11 September 2004; Revised 20 May 2005; Accepted 20 May 2005; Published online 7 July 2005.

Abstract

The purpose of our study was to evaluate the behaviour of blood pressure (BP) by ambulatory monitoring of blood pressure (AMBP) in 53 patients with primary hyperparathyroidism (PHPT) compared to 100 essential hypertensive (EH) and 31 healthy subjects (HS). The correlations between calcium–phosphorus metabolism and haemodynamic parameters in all groups are included in the study. AMBP was performed using the oscillometric technique (Space-Labs, 90207, Redmond, WA, USA) and the following AMBP parameters were evaluated: average day time systolic (S) and diastolic (D) blood pressure (BP) and heart rate (HR) (when awake), average night time SBP, DBP and HR (when asleep) and average 24-h-SBP, DBP and HR. The definition of 'dipper' or 'non-dipper' subjects was established if night time SBP and DBP fall was >10% and <10%, respectively. In total, 25 PHPT patients (47.2%) were hypertensive (HT-PHPT) and 28 PHPT (52.8%) were normotensive (NT-PHPT). Mean 24-h-SBP and DBP obtained by AMBP was higher in HT-PHPT (P<0.05) and EH (P<0.05) than in NT-PHPT and HS. The multiple linear regression has shown that in PHPT-HT patients ionized calcium is an independent factor for the rise of 24-h-DBP values (r: 0.497; P<0.05) and daytime DBP values (r: 0.497; P<0.05). In 56% of HT-PHPT patients there is an absence of physiological BP nocturnal fall ('non-dipper'), which is statistically significant (P<0.05) compared with 'non-dipper' EH patients (30%). In conclusion, in our study the prevalence of hypertension in PHPT was 47%. AMBP revealed that the 'non-dipping 'pattern was much higher in HT-PHPT patients in respect to EH patients.