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.
|Number of pages||6|
|Journal||Journal of Human Hypertension|
|Early online date||17 Sept 2015|
|Publication status||Published - Jun 2016|