Positive and Negative Aspects of Sodium Intake in Dialysis and Non-Dialysis CKD Patients

Sodium intake theoretically has dual effects on both non-dialysis chronic kidney disease (CKD) patients and dialysis patients. One negatively affects mortality by increasing proteinuria and blood pressure. The other positively affects mortality by ameliorating nutritional status through appetite induced by salt intake and the amount of food itself, which is proportional to the amount of salt under the same salty taste. Sodium restriction with enough water intake easily causes hyponatremia in CKD and dialysis patients. Moreover, the balance of these dual effects in dialysis patients is likely different from their balance in non-dialysis CKD patients because dialysis patients lose kidney function. Sodium intake is strongly related to water intake via the thirst center. Therefore, sodium intake is strongly related to extracellular fluid volume, blood pressure, appetite, nutritional status, and mortality. To decrease mortality in both non-dialysis and dialysis CKD patients, sodium restriction is an essential and important factor that can be changed by the patients themselves. However, under sodium restriction, it is important to maintain the balance of negative and positive effects from sodium intake not only in dialysis and non-dialysis CKD patients but also in the general population.