Race and sex differences in asleep blood pressure: The Coronary Artery Risk Development in Young Adults (CARDIA) study

Nocturnal hypertension and non-dipping blood pressure are each associated with increased risk of cardiovascular disease. We determined differences in nocturnal hypertension and non-dipping systolic/diastolic blood pressure among black and white men and women who underwent 24-hour ambulatory blood pressure monitoring at the Coronary Artery Risk Development in Young Adults study Year 30 Exam in 2015-2016. Asleep and awake periods were determined from actigraphy complemented by sleep diaries. Nocturnal hypertension was defined as mean asleep systolic/diastolic blood pressure ≥ 120/70 mm Hg. Non-dipping systolic and diastolic blood pressure, separately, were defined as a decline in awake-to-asleep blood pressure < 10%. Among 767 participants, the prevalence of nocturnal hypertension was 18.4% and 44.4% in white and black women, respectively, and 36.4% and 59.9% in white and black men, respectively. After multivariable adjustment and compared with white women, the prevalence ratio (95% confidence interval) for nocturnal hypertension was 1.65 (1.18-2.32) for black women, 1.63 (1.14-2.33) for white men, and 2.01 (1.43-2.82) for black men. The prevalence of non-dipping systolic blood pressure was 21.5% and 41.0% in white and black women, respectively, and 20.2% and 37.9% in white and black men, respectively. Compared with white women, the multivariable-adjusted prevalence ratio (95% confidence interval) for non-dipping systolic blood pressure was 1.66 (1.18-2.32), 0.91 (0.58-1.42) and 1.66 (1.15-2.39) among black women, white men, and black men, respectively. Non-dipping diastolic blood pressure did not differ by race-sex groups following multivariable adjustment. In conclusion, black women and men have a high prevalence of nocturnal hypertension and non-dipping systolic blood pressure.