LAUSR

Diet therapy for hyperkalemia in chronic kidney disease (CKD) is at a crossroads: many researchers and clinicians are no longer recommending the low-potassium diet, which has defined practice for the last half century, and instead are favoring a high-potassium, plant-rich diet. Central to this shift is the observation that reported dietary potassium intake is not associated with plasma potassium concentrations. However, kinetic studies using potassium salts indicate that people with CKD have impaired potassium tolerance that may make them susceptible to transient increases in plasma potassium levels from dietary potassium (postprandial hyperkalemia). Observational studies generally measure plasma potassium in the fasting state and before hemodialysis treatment, and therefore may not detect the acute effects of dietary potassium on plasma potassium concentrations. Differences between the acute and chronic effects of dietary potassium on plasma potassium levels may help explain clinical experiences and case studies attributing hyperkalemic episodes in patients with CKD to intakes of high-potassium foods despite their apparent lack of association. To reconcile these findings, an etiology-based approach to managing hyperkalemia is proposed in this review. The approach combines key elements of the low-potassium and plant-rich diets, and adds new features of meal planning to lower the risk of postprandial hyperkalemia.