Morning blood pressure surge in young black and white adults: The African-PREDICT Study.

An exaggerated morning blood pressure surge (MBPS) has independent predictive value for cardiovascular mortality and is suggested to be prevalent in elderly hypertensive patients: men and white populations. To better understand the MBPS profile in a young and normotensive population, we evaluated the MBPS in young adults and explored associations with demographic, cardiovascular and health behaviour measurements. We included 845 black (n = 439) and white (n = 406) men and women aged between 20 and 30 years. We calculated the sleep-trough and dynamic morning surge, and compared demographic data, health behaviours and ambulatory blood pressure according to MBPS quartiles. In the total group, higher waist circumference, socioeconomic score, lean mass, ambulatory blood pressure (24-h, daytime blood pressure) and increased night-time dipping (all p < 0.05) were found in the highest sleep-trough and dynamic morning surge quartiles. In the total white group, particularly men, both sleep-trough and dynamic morning surge were higher than the black group (all p < 0.013). More black participants were non-dippers than whites (44% vs 34%; p = 0.004). In multivariable adjusted regression in the total group, we found no consistent associations of MBPS with demographic and health behaviour measurements. MBPS related independently and positively with night-time percentage dipping in all ethnic groups (all p < 0.01). Ethnic differences in MBPS is evident in young adults, with a higher, but normal MBPS in white men. A non-dipping night-time pattern in young black adults (with reduced MBPS) and a higher MBPS (observed in dippers) may serve as potential risk factors for cardiovascular disease.