LAUSR

BACKGROUND The DASH diet lowers blood pressure (BP) more effectively in Blacks compared to other US racial subgroups. Considering chronic kidney disease (CKD) raises BP through complex mechanisms, DASH may affect BP differently among Blacks with and without CKD. We compared the association of DASH accordance to BP and prevalent hypertension among Blacks with and without CKD. METHODS Our study involved 3135 Black Americans enrolled in the Jackson Heart Study (2000-2004) with diet and office BP data. Using linear models adjusted for demographics, health behaviors, and clinical factors, we determined the association of a modified-DASH score (excluding sodium intake, ranging from 0-8 with increasing DASH accordance) with BP. We performed tests for interaction between DASH score and CKD status. RESULTS Among participants (mean age: 55 years; hypertension: 60%; CKD: 19%), the median DASH score was similar among participants with and without CKD (1.0 [IQR: 0.5-2] and 1.0 [IQR: 0.5-1.5]). CKD status modified the association of the DASH score with systolic BP (SBP) and diastolic BP (DBP) (p-interactions were 0.06 and <0.01). Among participants without CKD, SBP and DBP were not associated with the DASH score (-0.4 [95% confidence interval: -1.0, 0.1] mmHg and -0.1 [-0.4, 0.2] mmHg per one unit higher DASH score). Among participants with CKD, one unit higher DASH score was associated with lower SBP by 1.6 (0.5, 2.6) mmHg and lower DBP by 0.9 (0.3, 1.5) mmHg. CONCLUSIONS Despite low DASH scores overall, better DASH accordance was associated with lower BP among Black Americans with CKD.