Association between High Blood Pressure and Intakes of Sodium and Potassium among Korean Adults: Korean National Health and Nutrition Examination Survey, 2007-2012

Abstract

BackgroundThe association between dietary sodium and potassium, the ratio of sodium to potassium, and blood pressure remains unclear. ObjectiveWe evaluated the associations between blood pressure and dietary sodium and potassium intake in terms of the amount and ratio in Korean adults. DesignThis cross-sectional study was based on data from the fourth and fifth Korean National Health and Nutrition Examination Survey, 2007-2012. Participants/settingA total of 24,096 adults (aged ≥19 years) without history of antihypertensive medication use were selected. The 24-hour recall method was used for dietary assessment. We categorized the subjects into four groups using median intakes of sodium and potassium, and defined the low sodium/high potassium intake group as the reference group. Main outcome measuresHigh blood pressure (HBP) was defined as mean systolic or diastolic blood pressures of ≥140 or ≥90 mm Hg, respectively. Statistical analyses performedMultivariate logistic regression was performed to estimate the odds ratio and 95% CI to investigate the association between the four groups of sodium and potassium intakes and HBP. ResultsSodium intake was positively associated with diastolic blood pressure, with an increase of 0.21 mm Hg per 1 mg/kcal increase in sodium (P<0.001). In contrast, potassium intake was negatively associated with systolic blood pressure, with a decrease of 1.01 mm Hg per 1 mg/kcal increase in potassium (P<0.001). After adjusting for confounders, the high sodium/low potassium (odds ratio 1.21, 95% CI 1.02 to 1.44) and low sodium/low potassium intake groups (odds ratio 1.19, 95% CI 1.01 to 1.40) were at higher risk of HBP than the reference group. The risk of HBP in the high sodium/high potassium group did not differ from that in the reference group. ConclusionsLow potassium intake was associated with an increased risk of hypertension. These results suggest that increasing potassium intake might be beneficial for hypertension control among populations with low-potassium diets.