Association between Dietary Sodium and Potassium Intake with Chronic Kidney Disease in US Adults: A Cross-Sectional Study

Abstract

Background/Aims: Clinical guidelines recommend a diet low in sodium and high in potassium to reduce blood pressure and cardiovascular events. Little is known about the relationship between dietary sodium and potassium intake and chronic kidney disease (CKD). Methods: 13,917 participants from the National Health and Nutrition Examination Survey (2001-2006) were examined. Sodium and potassium intake were calculated from 24-hour recall and evaluated in quartiles. CKD was defined as estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m² or eGFR ≥60 ml/min/1.73 m² with albuminuria (>30 mg/g creatinine). Results: The mean (SE) age and eGFR of participants were 45.0 ± 0.4 years and 88.0 ± 0.60 ml/min/1.73 m², respectively. 2,333 (14.2%) had CKD: 1,146 (7.3%) had an eGFR <60 ml/min/1.73 m² and 1,514 (8.4%) had an eGFR ≥60 ml/min/1.73 m² and albuminuria. After adjustment for age, sex, race, BMI, diabetes, hypertension, cardiovascular disease and congestive heart failure, subjects in the highest quartile of sodium intake had lower odds of CKD compared to subjects in the lowest quartile (adjusted OR: 0.79; 95% CI: 0.66-0.96; p < 0.016). Compared to the highest quartile, the odds of CKD increased 44% for participants in the lowest quartile of potassium intake (adjusted OR: 1.44; 95% CI: 1.16-1.79; p = 0.0011). Conclusions: Higher intake of sodium and potassium is associated with lower odds of CKD among US adults. These results should be corroborated through longitudinal studies and clinical trials designed specifically to examine the effects of dietary sodium and potassium intake on kidney disease and its progression.