Arterial disease in dipper and nondipper hypertensive patients

Carotid artery and small vessel structural changes were evaluated in 45 dipper and 45 nondipper hypertensive subjects matched for sex, age, body mass index, smoking habit, and serum lipids. Patients underwent carotid ultrasonography to evaluate lumen diameter, intima-media thickness, cross-sectional area, and atherosclerotic plaques, and plethysmographic examination to record minimum forearm vascular resistance. In the whole study population, carotid cross-sectional area and prevalence of atherosclerotic plaques tended to be higher in nondippers than in dippers (19.9 +/- 6.0 v 17.5 +/- 6.1 mm2, P = .07, and 40% v 26%, P = .18), whereas intima-media thickness and minimum forearm vascular resistance were significantly higher in nondippers than in dippers (0.89 +/- 0.12 v 0.8 +/- 0.15 mm, P < .02, and 2.53 +/- 0.3 v 2.34 +/- 0.3 arbitrary resistance units (RU), P < .02). When gender was taken into account, different results were obtained in men and women. In men, vascular characteristics were not significantly different between dippers and nondippers. In women, carotid cross-sectional area and prevalence of atherosclerotic plaques tended to be higher in nondippers than in dippers (18.3 +/- 4.9 v 15.5 +/- 4.5 mm2, P = .06, and 40% v 15%, P = .15), and intima-media thickness and minimum forearm vascular resistance were significantly higher in nondippers than in dippers both before (0.84 +/- 0.1 v 0.73 +/- 0.1 mm, P < .01, and 2.38 +/- 0.3 v 2.16 +/- 0.2 RU, P < .01) and after adjustment for 24-h blood pressure. In conclusion, our data suggest that the progression of vascular disease may be differently affected in the two sexes by a different circadian blood pressure profile.