Relationship between Dietary Sodium to Potassium Ratio and Systolic Blood Pressure among US Adults Accordant and Non-Accordant with the Dietary Approach to Stop Hypertension (DASH) Diet, NHANES, 2009-2018

Abstract

Sodium (Na+) and potassium (K+) intake is a modifiable risk factor for hypertension. Recent studies show a strong association between the Na+/K+ ratio and blood pressure versus Na+ or K+ independently. The US guidelines recommend adherence to the DASH diet for controlling hypertension and cardiovascular diseases. Therefore, the study's aim is to examine the relationship between the Na+/K+ ratio and SBP in DASH diet accordant and non-accordant individuals. We performed secondary data analysis of the National Health and Nutrition Examination Survey (NHANES) 2009-2018, including 12,260 nonpregnant individuals ≥20 years-of-age. The DASH diet adherence score was dichotomized: ≥4.5 considered accordant; <4.5 considered non-accordant. Bivariate and multivariable linear regression analyses were used to examine the association between the Na+/K+ ratio and SBP in accordant and non- accordant participants, using SAS software 9.4. The age-adjusted Na+/K+ ratio was 1.09 (1.07, 1.11) and 1.43 (1.41, 1.44) in accordant and non-accordant individuals, respectively. SBP increased with Na/K ratio, 0.82 mmHg (0.08, 1.55), was higher in lower SES, Non-Hispanic Black males, and who reported heavy alcohol use, but lower in DASH accordant subjects with increasing age. In subpopulation analysis by DASH accordance, SBP increased with Na+/K+ ratio, 0.89 mmHg (0.06, 1.71) in non-accordant, but was not associated in accordant subjects. In conclusion, the ratio of dietary Na+/K+ is an important predictor of SBP. Adherence to the DASH diet reduces the association between the Na+/K+ ratio and SBP, suggesting that various nutrients in the DASH diet can contribute to the regulation of electrolyte excretion and SBP.