title: Prevalence and determinants of white coat effect in a large UK hypertension clinic population.
abstract: White coat hypertension (WCH) is common and termed white coat effect (WCE) in those on treatment for hypertension. The UK guideline suggests that all patients in stage 1 and 2 hypertension, but not stage 3 hypertension, should have ambulatory blood pressure monitoring (ABPM) performed before commencing treatment. The relationship between office blood pressure (BP) and ABPM and the factors that influence the WCE were examined in a large British cohort (n=2056) from 2 hypertension clinics (1998-2011). Data were collected prospectively: the median age was 56 years: 53% were female, 76% Caucasian, 9% African Caribbean, 15% South Asian and 86% taking antihypertensives. Fifty-one percent had WCE and differences between clinic BP and ABPM measurements increased with the stage of hypertension varying from 2/4 (normotensive), 13/10 (stage 1 hypertension), 24/14 (stage 2) and 40/20 mm Hg (stage 3). The degree of difference is greater in this study than described in other populations. A positive correlation was found between clinic systolic and diastolic BP and the WCE (r=0.74 and r=0.56, respectively, P<0.0001). Significant (P<0.05) independent associations of systolic WCE were clinic systolic BP (β=0.707), Caucasian ethnicity (South Asian β=-0.06; African Caribbean β=-0.043), female gender (male β=-0.047), nonsmoking status (smoker β=-0.100) and reduced renal function (estimated glomerular filtration rate β=-0.036). Significant independent associations of diastolic WCH were clinic diastolic BP (β=0.624), age (β=0.207), female gender (male β=-0.104), Caucasian ethnicity (South Asian β=-0.052, African Caribbean β=-0.079) and being a nonsmoker (β=-0.082) or ex-smoker (β=0.046). The results support current UK guidelines but suggest those with stage 3 hypertension would also benefit from ABPM.
authors.affiliation: Renal Unit, Heart of England NHS Foundation Trust, Birmingham, UK.
authors.forename: O
authors.initials: O
authors.lastname: Thomas
authors.affiliation: Renal Unit, Heart of England NHS Foundation Trust, Birmingham, UK.
authors.forename: K E
authors.initials: KE
authors.lastname: Shipman
authors.affiliation: Renal Unit, Heart of England NHS Foundation Trust, Birmingham, UK.
authors.forename: K
authors.initials: K
authors.lastname: Day
authors.affiliation: Renal Unit, Heart of England NHS Foundation Trust, Birmingham, UK.
authors.forename: M
authors.initials: M
authors.lastname: Thomas
authors.affiliation: Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, UK.
authors.forename: U
authors.initials: U
authors.lastname: Martin
authors.affiliation: Renal Unit, Heart of England NHS Foundation Trust, Birmingham, UK.
authors.forename: I
authors.initials: I
authors.lastname: Dasgupta
mesh_terms: D000328:Adult; D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects; D018660:Blood Pressure Monitoring, Ambulatory; D004739:England / Q000453:epidemiology; D005260:Female; D006784:Hospitals, Teaching; D006801:Humans; D008297:Male; D008875:Middle Aged; D010044:Outpatient Clinics, Hospital; D011237:Predictive Value of Tests; D015995:Prevalence; D044469:Racial Groups; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D059466:White Coat Hypertension / Q000175:diagnosis / Q000188:drug therapy / Q000208:ethnology* / Q000503:physiopathology
chemical_list: D000959:Antihypertensive Agents