title: A comparison between sphygmomanometer-based and ambulatory blood pressure monitoring in acute salt loading and depletion protocol.
abstract: BACKGROUND
  Ambulatory blood pressure monitors have been used in salt loading and depletion protocols. However, the agreement between measurements made using ambulatory blood pressure monitors and those made with the sphygmomanometer has not been evaluated.
  
  
  OBJECTIVE
  The objective of this study was to compare the concordance of the two methods of blood pressure measurements in protocols of acute salt loading and depletion.
  
  
  METHODS
  Systolic blood pressure was measured using a sphygmomanometer at the completion of salt infusion (2 L NaCl 0.9%, 4 h) and salt depletion (furosemide, 120 mg/day, p.o.) in 18 volunteers. Using the Pearson correlation coefficient (ρ), these readings were compared with the mean systolic blood pressure measured using the ambulatory blood pressure monitoring device during the following periods: 4 h of saline infusion and 12 h of salt depletion; 4 h of saline infusion and the last 6 h of salt depletion; 12 h of salt loading and the last 6 h of depletion; 12 h of salt loading and 12 h of depletion. Salt sensitivity was defined by a difference in the systolic blood pressure between salt loading and salt depletion greater than 10 mmHg when measured with the sphygmomanometer, and the Kappa analysis of concordance (K) was used with a significance level of P<0.05.
  
  
  RESULTS
  Only the blood pressure readings obtained using the ambulatory blood pressure device during 4 h of intravenous NaCl and during 12 h of salt depletion showed a high correlation with the variation in the systolic blood pressure measured by the sphygmomanometer, with a full agreement with the salt sensitivity classification (p = 0.71; P = 0.001 and K=1).
  
  
  CONCLUSIONS
  In acute salt loading and depletion protocols, an ambulatory blood pressure monitoring device should be used to record the blood pressure during the 4-h interval of salt infusion and 12-h interval of salt depletion.
authors.affiliation: Departamento de Clínica Medica, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Brazil.
authors.forename: Carlos Eduardo
authors.initials: CE
authors.lastname: Paiva
authors.forename: Andréia Fernanda Carvalho Leone
authors.initials: AF
authors.lastname: Aguiar
authors.forename: Fernando
authors.initials: F
authors.lastname: Nobre
authors.forename: Eduardo Barbosa
authors.initials: EB
authors.lastname: Coelho
mesh_terms: D000293:Adolescent; D000328:Adult; D000450:Aldosterone / Q000097:blood; D018660:Blood Pressure Monitoring, Ambulatory / Q000295:instrumentation / Q000379:methods*; D004232:Diuretics / Q000008:administration & dosage; D005260:Female; D005665:Furosemide / Q000008:administration & dosage; D006801:Humans; D006973:Hypertension / Q000175:diagnosis*; D008297:Male; D012083:Renin / Q000097:blood; D015203:Reproducibility of Results; D012964:Sodium / Q000652:urine; D012982:Sodium, Dietary / Q000008:administration & dosage*; D019722:Sphygmomanometers; D055815:Young Adult
chemical_list: D004232:Diuretics; D012982:Sodium, Dietary; D000450:Aldosterone; D005665:Furosemide; D012964:Sodium; D012083:Renin