title: Relationship between Joint National Committee-VI classification of hypertension and ambulatory blood pressure in patients with hypertension diagnosed by casual blood pressure.
abstract: BACKGROUND
  White-coat hypertension has been diagnosed arbitrarily based on different criteria. In 1997, the Joint National Committee-VI (JNC-VI) reported a new classification of hypertension and strongly emphasized the importance of ambulatory blood pressure (ABP) monitoring. The report pronounced normal ABP values for the first time.
  
  
  OBJECTIVE
  The study's aim was to clarify the relationship between casual blood pressure (BP) and ABP of patients with essential hypertension in each stage of JNC-VI classification, and the prevalence of white-coat hypertension diagnosed by using JNC-VI normal ABP criteria.
  
  
  METHODS
  Ambulatory blood pressure was monitored non-invasively in 232 patients with essential hypertension whose casual BP was > or = 140/90 mmHg. The patients were classified according to JNC-VI classification, and their casual BP was compared with ABP. The criterion of white-coat hypertension was defined as casual BP > or = 140/90 mmHg with normal ABP according to JNC-VI criteria (< 135/85 during daytime and < 120/75 during nighttime).
  
  
  RESULTS
  Mean ABP increased as the stage advanced, and the differences between casual BP and ABP also increased. There were considerable overlaps in the distribution of ABP among stages. The prevalence of white-coat hypertension was 13% overall: 30% of the patients with isolated systolic hypertension, 19% of those in stage 1, 10% in stage 2, and 4% in stage 3.
  
  
  CONCLUSIONS
  Classification of hypertension based on casual BP may not always correspond in severity to that based on ABP. Ambulatory blood pressure monitoring recommended by JNC-VI is very useful for the evaluation of hypertension to differentiate white-coat hypertension from true hypertension.
authors.affiliation: First Department of Internal Medicine, Nagoya University School of Medicine, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Inden
authors.forename: M
authors.initials: M
authors.lastname: Tsuda
authors.forename: H
authors.initials: H
authors.lastname: Hayashi
authors.forename: H
authors.initials: H
authors.lastname: Takezawa
authors.forename: S
authors.initials: S
authors.lastname: Iino
authors.forename: T
authors.initials: T
authors.lastname: Kondo
authors.forename: Y
authors.initials: Y
authors.lastname: Yoshida
authors.forename: M
authors.initials: M
authors.lastname: Akahoshi
authors.forename: M
authors.initials: M
authors.lastname: Terasawa
authors.forename: T
authors.initials: T
authors.lastname: Itoh
authors.forename: H
authors.initials: H
authors.lastname: Saito
authors.forename: M
authors.initials: M
authors.lastname: Hirai
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001795:Blood Pressure Determination; D018660:Blood Pressure Monitoring, Ambulatory; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D006973:Hypertension / Q000145:classification* / Q000175:diagnosis* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged