White coat hypertension in a general practice: Prevalence, cardiovascular risk factors and clinical implications

Abstract

Objective - To examine the prevalence of white coat hypertension (WCH) and white coat effect (WCE) in a general practice. Background and biochemical characteristics, triglycerides, total cholesterol, HDL cholesterol, fasting blood glucose, microalbuminuria, ECG, smoking habits, height and weight of patients with white coat hypertension were compared to patients with sustained hypertension. Design - Blood pressure measurements among mild hypertensives in clinic visits by doctor and at home by the patients.Setting - A primary health centre in Oslo, Norway. Subjects - Sixty-eight patients with mild hypertension (41 females and 27 males) aged 20-75 years. Main outcome measures - Patients had their blood pressure measured in clinic visits by general practitioners and by themselves at home to study the prevalence of WCH and the WCE. WCH was defined as a consistently increased blood pressure in the clinic and a normal home-measured blood pressure. WCE was defined as a difference in mean systolic blood pressure measured by physician and patients of 10 mmHg, or more. An individual risk score for myocardial infarction was calculated. Subjects with and without WCH/WCE were compared in relation to background characteristics and biochemical differences. Results - Fourteen patients (21%) were found with WCH, while 25 (37%) had WCE. Patients with WCH differed significantly from hypertensives in age, total cholesterol, and heart rate. In multivariate analysis, increasing age and heart rate were significant negative predictors for WHC. Conclusion - WCH may be a significant clinical challenge in general practice, especially among younger patients.