J Korean Med Sci.  2014 Sep;29(Suppl 2):S109-S116. 10.3346/jkms.2014.29.S2.S109.

Estimated 24-Hour Urine Sodium Excretion Is Correlated with Blood Pressure in Korean Population: 2009-2011 Korean National Health and Nutritional Examination Survey

• Oh J
• Lee J
• Koo HS
• Kim S
• Chin HJ

• KMID: 2069801
• DOI: http://doi.org/10.3346/jkms.2014.29.S2.S109

Abstract

No large-scale studies have investigated the association between salt intake and hypertension in Korean population. To investigate the relationship of blood pressure to salt consumption, we analyzed data from 19,476 participants in the 2009-2011 Korean National Health and Nutritional Examination Survey (KNHANES). Urinary sodium excretion over 24-hr (24HUNa) was estimated from spot urine tests using Tanaka's equation. The study subjects were stratified into hypertensive and normotensive groups. Hypertensive participants (n=6,552, 33.6%) had higher estimated 24HUNa, 150.4+/-38.8 mEq/day, than normotensive participants, 140.5+/-34.6 mEq/day (P<0.001). The association between 24HUNa and blood pressure outcomes was not affected by adjustment for other risk factors for hypertension (odds ratio 0.001; 95% confidence interval 0.001-0.003; P<0.001). Increases in 24HUNa of 100 mEq/day were associated with a 6.1+/-0.3/2.9+/-0.2 mmHg increase in systolic/diastolic blood pressure in all participants. This effect was stronger in hypertensive participants (increase of 8.1+/-0.5/3.4+/-0.3 mmHg per 100 mEq/day) and smaller in normotensive participants (2.9+/-0.3/1.3+/-0.2 mmHg). These results support recommendations for low salt intake in Korean population to prevent and control adverse blood pressure levels.

Keyword

Hypertension; Blood Pressure; Sodium

MeSH Terms

Adult
Algorithms
Asian Continental Ancestry Group
Blood Pressure/*physiology
Demography
Female
Humans
Hypertension/epidemiology/*urine
Logistic Models
Male
Middle Aged
Nutrition Surveys
Prevalence
Republic of Korea/epidemiology
Risk Factors
Sodium, Dietary/*urine
Urine Specimen Collection
Sodium, Dietary

Figure

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  Fig. 1 Prevalence of hypertension among men and women; KNHANES, 2009-2011.

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  Fig. 2 Participants with hypertension had higher estimated 24-hr urinary sodium excretion than normotensive participants. The midline of the boxes represents the median and the lower and upper margins represent the 25th and 75th percentiles, respectively. The lower and upper ends represent the minimum and maximum values, respectively.

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  Fig. 3 Upper panels, mean systolic (solid lines) and diastolic (dotted lines) blood pressure of HTN group (black line) and NBP group (gray line) in relation to the age group by gender. Vertical lines denote the standard deviation of the mean; lower panels, mean 24-hr urine Na excretion (calculated by the Tanaka equation) of HTN group (black bar) and NBP group (gray bar) in relation to the age group by gender among the KNHANES 2009-2011. Error bars represent the standard deviation of the mean; *Denotes P < 0.05.

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