ORIGINAL ARTICLE Ambulatory monitoring of blood pressure (AMBP) in patients with primary hyperparathyroidism C Letizia 1,2 , P Ferrari 1,2 , D Cotesta 1,2 , C Caliumi 1,2 , R Cianci 1 , S Cerci 1 , L Petramala 1,2 , M Celi 1,2 , S Minisola 1 , E D’Erasmo 1,2 and GF Mazzuoli 1 1 Department of Clinical Science, University of Rome ‘La Sapienza’, Rome, Italy; 2 Day Hospital of Internal Medicine and Arterial Hypertension, University of Rome ‘La Sapienza’, Rome, Italy 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 in- cluded 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 410% and o10%, respec- tively. In total, 25 PHPT patients (47.2%) were hyperten- sive (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 (Po0.05) and EH (Po0.05) 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; Po0.05) and daytime DBP values (r : 0.497; Po0.05). In 56% of HT-PHPT patients there is an absence of physiological BP nocturnal fall (‘non-dipper’), which is statistically significant (Po0.05) 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. Journal of Human Hypertension (2005) 19, 901–906. doi:10.1038/sj.jhh.1001907; published online 7 July 2005 Keywords: blood pressure; ambulatory monitoring blood pressure; essential hypertension; primary hyperparathyroid- ism; dipper and non-dipper Introduction Primary hyperparathyroidism (PHPT) is a patholo- gical condition characterized by excessive secretion of the parathyroid hormone (PTH) from one or more parathyroid glands, not related to homeostatic requirements and associated with hypercalcaemia. 1 PHPT is more prevalent in women over 50 years and in most cases is due to adenoma (80–85%), hyperplasia (15–20%), multiple adenoma (4–5%) and carcinoma (1%). 2 In the literature, there is evidence, which shows that PHPT is associated with an increase in cardiovascular risk. An association between PHPT and hypertension has been accepted for 40 years, with a prevalence of the latter that varies between 20 and 80%. 3–5 In some studies, most patients with PHPT and hypertension have blood pressure (BP) values that significantly decrease after parathyroidectomy. 6 That allows these patients to reduce antihyperten- sive treatment or even to stop it definitively. 3,7–9 Ambulatory monitoring of blood pressure (AMBP), using either invasive or noninvasive recorders, has shown that BP tends to be higher during the day and lower at night in normotensive subjects. 10–14 In particular, some hypertensive patients do not exhibit the normal nocturnal BP fall, and they have been called ‘non-dippers’, whereas those with normal circadian rhythm have been called ‘dippers’. 15–18 Moreover, studies that used AMBP showed that the reduction in night time BP seems to lower in secondary forms of hypertension. 17–21 The aim of our study was to assess the behaviour of BP by ABPM in patients with PHPT, evaluating Received 11 September 2004; revised and accepted 20 May 2005; published online 7 July 2005 Correspondence: Professor C Letizia, Department of Clinical Science, Policlinico Umberto I, Viale del Policlinico 155, 00156 Rome, Italy. E-mail: claudio.letizia@uniroma1.it Journal of Human Hypertension (2005) 19, 901–906 & 2005 Nature Publishing Group All rights reserved 0950-9240/05 $30.00 www.nature.com/jhh