IS THE ABSENCE OF A NORMAL NOCTURNAL FALL IN BLOOD-PRESSURE (NONDIPPING) ASSOCIATED WITH CARDIOVASCULAR TARGET ORGAN DAMAGE

Objective To determine whether the failure to decrease blood pressure normally during sleep is associated with more prominent target organ d amage. Methods Cardiac and vascular structure and function were charac terized in 183 asymptomatic, unmedicated hypertensive patients and com pared with their ambulatory blood pressures. Results The 104 patients with a normal (>10%) nocturnal fall in systolic blood pressure (dipper s) were similar to the 79 patients with an abnormal fall (nondippers) in sex, race, body size, smoking history, and average awake ambulatory blood pressure. Nondippers tended to be older (57 versus 54 years, P= 0.06). The supine blood pressure upon completion of the ultrasound st udies was higher in the nondippers (156/93 versus 146/89 mmHg, P< 0.00 5) as was the variability of the awake diastolic blood pressure, There were no differences between dippers and nondippers in left ventricula r mass (170 versus 172 g), mass index (90 versus 91 gm/m2), prevalence of abnormal ventricular geometry, common carotid artery diameter (5.7 4 versus 5.75 mm), and vascular strain. Although nondippers were more likely to have carotid artery plaque (41 versus 27%, P= 0.053) and an increased intimal-medial thickness (0.84 versus 0.79 mm, P < 0.05), ad justment for age rendered the differences insignificant. There were no differences in the relation of awake and steeping systolic pressures to the left ventricular mass (r = 0.36 and 0.35, respectively, both P < 0.005) or to the carotid wall thickness (r = 0.28 and 0.29, respecti vely, both P< 0.005). When the 114 men and 69 women were considered se parately, similar findings were obtained. When the 109 whites and 56 b lacks (African-Americans and Afro-Caribbeans) were considered separate ly, there were no differences in left ventricular structure in either group, and differences in vascular structure were confined to the whit e subgroup. Conclusion The lack of a normal nocturnal tall in blood pr essure is not associated with an increase in left Ventricular mass or in arterial disease independently of age. Age-related changes in carot id artery wall thickness and plaque among nondippers may reflect a con tribution of an altered baroreceptor function to the lack of normal no cturnal and supine blood pressure decreases.