title: Detecting sodium-sensitivity in hypertensive patients: information from 24-hour ambulatory blood pressure monitoring.
abstract: Sodium sensitivity is an important cardiovascular risk factor for which a diagnosis requires a time-consuming protocol, the implementation of which is often challenging for patients and physicians. Our aim was to assess the reliability of an easier approach based on data from 24-hour ambulatory blood pressure monitoring performed in hypertensive subjects during daily-life conditions and habitual diet. We enrolled 46 mild to moderate hypertensive subjects who underwent 24-hour ambulatory blood pressure monitoring during usual sodium intake. Patients were divided into 3 classes of sodium sensitivity risk on the basis of ambulatory blood pressure monitoring data: low risk if dippers and a 24-hour heart rate ≤ 70 bpm; high risk if nondippers and a 24-hour heart rate of > 70 bpm; intermediate risk with the remaining combinations (dippers with heart rate > 70 bpm or nondippers with heart rate ≤ 70 bpm). Then patients underwent a traditional sodium sensitivity test for the dichotomous classification as sodium sensitive or sodium resistant and for evaluating the sodium sensitivity index. Prevalence of sodium-sensitive patients and mean value of sodium sensitivity index were calculated in the 3 risk classes. The sodium sensitivity index markedly and significantly increased from the low-risk to the high-risk class, being equal to 19.9 ± 14.4, 37.8 ± 8.3, and 68.3 ± 17.0 mm Hg/(mol/day) in the low-risk, intermediate-risk, and high-risk classes, respectively (M ± SEM). Also, the prevalence of sodium-sensitive patients increased significantly from the low-risk class (25%) to the intermediate-risk (40%) and high-risk (70%) classes. Thus, performance of 24-hour ambulatory blood pressure monitoring in daily-life conditions and habitual diet may give useful information on the sodium sensitivity condition of hypertensive subjects in an easier manner than with the traditional sodium sensitivity test approach.
authors.affiliation: Department of Cardiology, Ospedale San Luca, Istituto Auxologico Italiano, Milan, Italy. gianfranco.parati@unimib.it
authors.forename: Paolo
authors.initials: P
authors.lastname: Castiglioni
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Parati
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Brambilla
authors.forename: Valerio
authors.initials: V
authors.lastname: Brambilla
authors.forename: Massimo
authors.initials: M
authors.lastname: Gualerzi
authors.forename: Marco
authors.initials: M
authors.lastname: Di Rienzo
authors.forename: Paolo
authors.initials: P
authors.lastname: Coruzzi
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000187:drug effects*; D018660:Blood Pressure Monitoring, Ambulatory / Q000379:methods*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D017673:Sodium Chloride, Dietary / Q000008:administration & dosage*
chemical_list: D017673:Sodium Chloride, Dietary