Abstract
BACKGROUND: On average, Black adults compared to White adults have higher ambulatory blood pressure (ABP), particularly during sleep.
METHODS: Participants were randomly assigned to eat a control diet or the DASH diet (n = 335 with ABP, 58% self-reported Black). On their assigned diet, participants had three, randomly ordered, 30-day feeding periods with different sodium levels (low, intermediate, and high). ABP was obtained at the end of each period.
RESULTS: Compared to the control diet with high sodium (reference), reducing sodium and consuming the DASH diet, alone or combined, significantly lowered 24-hour, awake, and asleep systolic and diastolic ABP in Black and Non-Black participants. The DASH diet with low sodium reduced mean (95%CI) awake SBP by 9.0mmHg (6.4, 11.7) in Black participants and 7.5mmHg (4.5, 10.6) in Non-Black participants, and mean asleep SBP by 8.0mmHg (4.8, 11.2) in Black participants and 7.4mmHg (3.9,11.0) in Non-Black participants in comparison to the reference (each P < .05). Despite reductions in asleep ABP from the DASH diet and sodium reduction, significant differences by race persisted in achieved ABP, consistently so for asleep ABP. Mean±SE achieved levels of asleep SBP on the control diet with high sodium were 124.1 ± 0.6mmHg in Black participants and 120.2 ± 0.7mmHg in Non-Black participants (P < .005), while on the DASH diet with low sodium, achieved levels were 115.2 ± 0.5mmHg in Black participants and 112.5 ± 0.7mmHg in Non-Black participants (P < .005).
CONCLUSIONS: Despite clinically relevant reductions in ABP from sodium reduction and the DASH diet in both Black and Non-Black participants, racial differences in achieved levels of asleep ABP persisted.
