Relationship between sodium intake and blood pressure according to metabolic syndrome status in the Korean National Health and Nutrition Examination Survey

Abstract

Objectives The relationship between sodium intake and blood pressure (BP) in population studies varies depending on the dietary habit and the characteristics of the population studied. Asian dietary patterns and salt sensitivity have been suggested to explain this association. Aging and metabolic syndrome (MS) are the most common reasons for salt sensitivity in populations. Participants and methods We therefore examined the dietary patterns in the Korean National Health and Nutrition Examination Survey. Results In a multiple regression model for 3757 patients, age, antihypertensive medication, BMI, family history of hypertension, and MS were positively associated with systolic BP, whereas female sex, income, educational status, and fruit intake were negatively associated with systolic BP. Fruit intake was the only dietary factor that was negatively associated with systolic BP (P = 0.017). In MS (n = 712), sodium and fruit intake was independently positively and negatively associated with systolic BP, respectively, discounting age and medication. In contrast, in normal individuals (n = 3045), diet was not related to systolic BP. The relationship between diet and systolic BP is more clear-cut in MS. Conclusion Dietary pattern and salt sensitivity at the population level could be a cause of the relationship between sodium intake and BP.