Prevalence, predictive factor, and clinical significance of white-coat hypertension and masked hypertension in Korean hypertensive patients.
BACKGROUND
The prevalence and clinical significance of white-coat hypertension (WCHT) and masked hypertension (MHT) are unknown in Koreans. Here we measure the frequency of WCHT and MHT in hypertensive subjects and identify the epidemiologic and/or clinical factors that predict it in Korean subjects.


METHODS
This study is a retrospective analysis of a random sample from February 2004 to October 2005. All patients had measurements of blood pressure (BP) in the clinic and 24-hour ambulatory blood pressure monitoring (ABPM). Subjects were classified into four groups on the basis of daytime ambulatory BP and clinic BP level: 1) Normotension (NT), 2) MHT, 3) WCHT, and 4) sustained hypertension (SHT).


RESULTS
For all 967 patients, the mean clinic BP was 157.7 +/- 22.0/ 95.3 +/- 13.1 mmHg, and the mean daytime ambulatory BP was 136.4 +/- 15.0/ 86.2 +/- 10.7 mmHg. The NT, MHT, WCHT, and SHT groups consisted of 51 (5.3%), 55 (5.7%), 273 (28.2%), and 588 (60.8%) subjects, respectively. The left ventricular mass index was significantly higher in SHT than in the other groups, and was positively correlated with BP, especially ABPM. Compared with NT, the factors associated with MHT were younger age, male gender, higher BMI, clinic BP > or = 130 mmHg, and alcohol consumption. Compared with SHT, the factors associated with WCHT were female gender, lower BMI, and clinic BP < 150 mmHg.


CONCLUSIONS
WCHT and MHT were prevalent in the hypertensive population. ABPM was more predictive of target organ damage than clinic BP, and could be useful in identifying subjects at risk for WCHT and MHT.
Hwang
Eui-Seock
ES
Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
Choi
Kee-Joon
KJ
Kang
Duk-Hyun
DH
Nam
Gi-Byoung
GB
Jang
Jae-Sik
JS
Jeong
Young-Hoon
YH
Lee
Chang-Hoon
CH
Lee
Ji-Young
JY
Park
Hyun-Koo
HK
Park
Chong-Hun
CH
D018660:Blood Pressure Monitoring, Ambulatory; D005260:Female; D006305:Health Status Indicators; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D006973:Hypertension / Q000000981:diagnostic imaging / Q000453:epidemiology*; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging / Q000503:physiopathology*; D007723:Korea / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012189:Retrospective Studies; D012307:Risk Factors; D014463:Ultrasonography