Patients whose blood pressure readings are elevated when measured in a clinical setting but are within normal range in nonmedical environments are considered to have “white coat,” or transient, hypertension. Although it traditionally has been regarded as a benign condition, recent studies have revealed correlations between white coat hypertension and unfavorable risk factors in young adults. Muscholl and colleagues studied left ventricular structure and function in patients with white coat hypertension.
During the community-based study, data were collected, and echocardiographic studies were performed on 845 men and 832 women who were 25 to 74 years of age. Repeated blood pressure readings were taken by technicians, using standardized protocols. The technicians did not wear white coats, and the environment was structured to appear informal and nonclinical. Patients were not told their blood pressure levels until three readings had been taken. Within 60 minutes of the technicians' readings, blood pressure levels were measured by a physician wearing a white coat who was introduced as a cardiologist. Echocardiography was performed immediately before the blood pressure measurement was taken by the physician.
Patients meeting the criteria for white coat hypertension had blood pressure readings that were normal (less than 140/90 mm Hg) when taken by a technician but reached hypertensive levels (160/95 mm Hg or higher) when recorded by a physician. The prevalence of white coat hypertension was higher in men (10.9 percent) than in women (8.2 percent); overall, 10 percent of the study population displayed the condition.
Even after adjusting for age, sex and body mass index, patients with white coat hypertension had significantly increased left ventricular mass indexes. The increased cardiac mass was due to increased thickness of the posterior wall and the septum of the left ventricle. Patients with white coat hypertension did not show abnormal systolic function of the left ventricle and had no abnormalities of diastolic filling or left atrial size.
The authors conclude that white coat hypertension is a common condition that can no longer be dismissed as benign or as having no consequence. They believe the finding is related to an increased risk of left ventricular hypertrophy and cardiac remodeling. They advocate more intense monitoring and control of cardiovascular risk factors in adults found to have elevated blood pressure readings exclusively in clinical settings.