White coat hypertension and carotid atherosclerosis

To investigate further the relationship between atherosclerotic vascular di sease and blood pressure, and the phenomenon of white coat hypertension, we performed a cross-sectional study of patients referred for carotid Doppler scanning, to determine the relationship between ambulatory blood pressure monitoring (ABPM) and carotid atherosclerosis. We studied 79 patients (51 m en, 28 women) undergoing Doppler ultrasound examination of the carotid arte ries: 44 (56%) had evidence of carotid atherosclerosis on Doppler ultrasoun d examination ("disease group"), whilst 35 (44%) had normal carotid arterie s ("controls"). "Adequate" ABPM recordings, defined by > 90% of recordings over the 24 h, were available in 51 patients (30 positive, 21 negative). Th ere were no significant differences in mean daytime, mean night-time or mea n 24 h ABPM recordings between those with and without carotid atheroscleros is. Mean manual clinic systolic blood pressure was significantly greater in those with carotid atherosclerosis than in controls (146.7 +/- 25.2 vs 131 .1 +/- 35 mmHg, p < 0.005). In patients with carotid atherosclerosis, the f irst systolic blood pressure ABPM recording was not significantly different from the mean manual clinic recording (mean difference -1.5 mmHg, 95% conf idence interval (CI) -7.9 to 4.8 mmHg). The initial diastolic blood pressur e ABPM recording was significantly higher than the mean manual recording. C arotid atherosclerosis was identified in 53% of normotensive controls compa red with 56% of white coat hypertensives and 75% of persistent hypertensive s. One-third (9/27) of the patients with normal carotid arteries did not ha ve nocturnal dipping ("non-dippers") compared with 50% (12/24) of the ather osclerotic patients. This study suggests that carotid atherosclerosis may b e associated with white coat hypertension. Our study adds to the body of ev idence that white coat hypertension is associated with end-organ damage and is not simply a benign disease. Such patients should be screened for other cardiovascular risk factors and should be monitored for the development of persistent hypertension.