# Age-period-cohort analysis of dietary sodium, potassium, and sodium-to-potassium ratio in Korea

## TL;DR

This study examines trends in sodium and potassium intake in Korea over 16 years and finds that higher sodium-to-potassium ratios are linked to increased blood pressure and hypertension risk.

## Contribution

The study provides novel insights into age-period-cohort trends of dietary sodium, potassium, and their ratio in Korea and their associations with blood pressure and hypertension.

## Key findings

- Sodium intake decreased across all age groups, but remains excessive relative to recommendations.
- A higher sodium-to-potassium ratio was strongly associated with elevated systolic and diastolic blood pressure and increased odds of hypertension.
- Potassium intake increased slightly in recent years but remains suboptimal, particularly in younger adults.

## Abstract

Excessive sodium and insufficient potassium consumption are major dietary contributors to hypertension (HTN) and cardiovascular diseases. The sodium-to-potassium ratio is a known predictor of blood pressure (BP) and HTN. This study evaluated 16-year-trends in dietary sodium, potassium, and the sodium-to-potassium ratio, and their associations with BP and HTN in Korea.

Data from 76,484 participants aged 19-79 years were obtained from the Korea National Health and Nutrition Examination Survey conducted in 2007-2022. Sodium and potassium intake were assessed using 24-hour recalls, and the sodium- to-potassium ratio was calculated. All values were energy-adjusted using the residual method. Age-period-cohort (APC) models were used to analyze temporal trends. Associations with BP and HTN were examined using multivariate linear and logistic regression models, adjusting for confounders.

Energy-adjusted sodium intake decreased across all age groups, and potassium slightly increased in the recent 5 years, though both remained suboptimal relative to recommendations. APC analyses showed increasing potassium intake with age and a reversed U-shape cohort pattern. The sodium-to-potassium ratio decreased with age and calendar year but increased in recent cohorts. A higher sodium-to-potassium ratio was strongly associated with elevated systolic (β=0.028, p<0.001) and diastolic BP (β=0.036, p<0.001), and increased odds of HTN (odds ratio, 1.19; 95% confidence interval, 1.07 to 1.33). A linear association appeared when the sodium-to-potassium ratio exceeded 1.00 in the spline model.

Despite improvements, sodium intake remains excessive, and potassium insufficient, particularly in younger adults and recent cohorts. Public health interventions should prioritize reducing sodium and promoting potassium-rich foods to reduce cardiovascular risk.