Trends in Urinary Sodium-to-Potassium Ratios in Koreans: Analysis of KNHANES 2016–2023 Data

Figures

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  Figure 1. Urinary sodium, potassium, and their ratio (Na/K ratio) in KNHANES 2016–2023. (a) Kernel density plots of urinary sodium (top), urinary potassium (middle) (b), and urine Na/K ratio (bottom) (c). Each KNHANES phase was represented using a consistent color hue, with darker shades indicating more recent survey years within the same phase. KNHANES Phase VII (2016–2018) was depicted in shades of red, Phase VIII (2019–2021) in shades of green, and Phase IX (2022–2023) in shades of blue.

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  Figure 2. Annual trends in the number and mean age of participants, mean and median urine Na/K ratio, and the prevalence of urine Na/K ratio <1, <2, and <4 (mmol/mmol) from 2016 to 2023.

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  Figure 3. Median urinary sodium (Na), potassium (K), and Na/K ratio, along with the number of participants by sex, age group, and year. (a) Median urinary sodium concentration; (b) median urinary potassium concentration; and (c) median urinary Na/K ratio. Line graphs represent the median urinary Na, K, and Na/K ratio stratified by sex and age group for each year from 2016 to 2023 (males in the top panels, females in the bottom). Bar graphs in the background indicate the number of participants (n) in each corresponding age group and year.

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  Figure 4. Prevalence of urinary sodium-to-potassium (Na/K) ratios <1, <2, and <4 by age group, sex, and survey year with participant counts. Bar graphs in the background indicate the number of participants (n) in each corresponding age group and year, with darker colors corresponding to more recent survey years within each KNHANES phase. The line graphs are shown as a reference for Na/K thresholds in 2016: dark for <1 (bottom), medium for <2 (middle), and light for <4 (top), illustrating the relative intensity used for all survey years. Bar graphs in the background show the number of participants in each age group and year (left y-axis).

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  Figure 5. Prevalence of urinary sodium-to-potassium (Na/K) ratios ≥ 4 (top) and ≥ 2 (bottom) by age group and survey year with participant counts in male (a) and female (b) subjects. Bar graphs in the background indicate the number of participants (n) in each corresponding age group and year (left y-axis).

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  Figure 6. Multiple logistic regression analysis for factors associated with urinary sodium-to-potassium (Na/K) ratios ≥ 4. This forest plot illustrates the adjusted odds ratios and 95% confidence intervals (CIs) for predictors of having sodium-to-potassium (Na/K) ratios ≥ 4, based on a generalized linear model for complex surveys. The size of each square corresponds to the absolute value of the logarithmic odds ratio, indicating the relative weight of each variable in the model.