Association of Sodium and Potassium Intake and Blood Pressure in US Children

Background: The prevalence of hypertension in children continues to rise in the United States. While multifactorial, major contributing factors include changes in lifestyle and dietary trends. Traditional management of hypertension with sodium reduction is well accepted in practice, although newer data suggests high potassium intake may play a larger role. Nevertheless, previous studies have been limited to the adolescent population, utilizing outdated hypertension guidelines for children. Methods: We conducted a cross-sectional analysis of children using data from eight National Health and Nutrition Examination Survey (NHANES) cycles (2003–2004 to 2017-March 2020) who had blood pressure data available. Individuals on low-sodium/potassium or renal diets were excluded. Multiple linear regression models were used to assess associations of systolic and diastolic blood pressure indexes with dietary potassium intake and the sodium-to-potassium intake (Na/K) ratio. Logistic regression models were used to evaluate associations with hypertension status. All models were adjusted for age, sex, race/ethnicity, BMI percentile, and mean intakes of total sugar, fiber, and fat based on two consecutive 24-hour dietary recalls. Results: The study population included 15,689 participants aged 8–18 years. Among the children, 49.8% were female, 28.6% were non-Hispanic white, and 27.6% were non-Hispanic Black. Approximately 3% of the cohort met pediatric criteria for hypertension. Regression analysis found a significant association between increased potassium intake and lower diastolic blood pressure index (p-value: < 2.2e-16). The effect size was small, with a 50% increase in dietary potassium intake associated with a 0.01 (0.8 mmHg for adolescents) decrease in diastolic blood pressure index. Na/K was not associated with blood pressure index. Neither potassium intake nor Na/K was associated with hypertension. Conclusion: We find that higher potassium intake is associated with a lower diastolic blood pressure index, with a small effect size and unclear clinical significance. Neither potassium intake nor Na/K was associated with hypertension, potentially related to the rarity of hypertension in the cohort. Further evaluation with rigorous nutritional intake capture and serial blood pressure evaluation is needed to determine if lifestyle modification with increased potassium intake would be clinically actionable.