Twenty-four hour ambulatory blood pressure monitoring in general practice.

OBJECTIVES To assess the role of ambulatory blood pressure (BP) monitoring in the diagnosis of hypertension in general practice. BACKGROUND Hypertension is usually diagnosed by means of casual office BP readings. However, ambulatory BP monitoring has shown that a significant proportion of patients diagnosed as hypertensive do not in fact have hypertension. METHOD Sixty-four Indian patients diagnosed as having mild to moderate hypertension by means of casual measurements were subjected to 24-hour ambulatory blood pressure monitoring (ABPM). A BP load of > 35% was classified as true hypertension and < 35% as 'white coat' hypertension. White coat hypertensives were compared with the true hypertensive group with regard to various demographic characteristics, as well as to correlate ABPM and casual BP readings. RESULTS A 23.44% prevalence of white coat hypertension was found. In addition, the demographic profile of such patients showed a preponderance of non-obese females (73.33%), the majority of whom were on concomitant medication (60%). A poor correlation was found between the casual office BP readings and the 24-hour ambulatory BP readings in the white coat hypertensive group compared with the true hypertensive group. CONCLUSION White coat hypertension is common in patients diagnosed as having mild to moderate hypertension by means of casual BP readings. There are no reliable clinical indicators to identify patients with white coat hypertension. ABPM has been shown to be a useful method for differentiating white coat hypertensive groups from true hypertensive groups.