Nocturnal Non-dipping Blood Pressure Profile in Black Normotensives Is Associated with Cardiac Target Organ Damage.

PURPOSE: A non-dipping pattern of nocturnal blood pressure in hypertensive patients is an established predictor of cardiovascular risk, especially in Blacks. However, data on non-dipping normotensives and cardiovascular risk in this population is sparse. In this study, we aim to determine if a non-dipping profile in a cohort of Black normotensives is associated with cardiac target organ damage.

METHODS: We studied ambulatory blood pressure patterns in 43 normotensive Black patients of Caribbean origin and classified their profiles as dippers (DP) and non-dippers (NDP) based on their nocturnal blood pressure profiles. Cardiac target organ damage was estimated from 2-D echocardiogram.

RESULTS: The mean age of the cohort was 52 years. Both groups were similar with respect to baseline age, sex, weight, height, body mass index and daytime ambulatory BP. There was a statistically significant difference in nocturnal blood pressure between DP and NDP groups (112 ± 7/64 ± 2 mm Hg vs 117 ± 3/69 ± 2 mm Hg, P=.004). The NDP cohort showed evidence of cardiovascular target damage on echocardiography with a significantly increased relative wall thickness (.35 ± .07 cm vs .42 ± .05 cm, P=.001), left ventricular mass index (95 ± 14 vs 105 ± 14 g/m(2), P=.018) and left atrial volume index (26 ± 3.5 vs. 30 ± 3.4, P=.001). Left ventricular geometry in the non-dippers also showed increased concentric remodeling, concentric and eccentric hypertrophy.

CONCLUSIONS: Our study demonstrates that nocturnal non-dipping of blood pressure in normotensive Blacks of Caribbean origin may be associated with cardiovascular end organ damage thereby providing new surveillance and therapeutic targets.