Chronic Hyperkaliemia in Chronic Kidney Disease: An Old Concern with New Answers

Abstract

Increasing potassium intake ameliorates blood pressure (BP) and cardiovascular (CV) prognoses in the general population; therefore the World Health Organization recommends a high-potassium diet (90-120 mEq/day). Hyperkalaemia is a rare condition in healthy individuals due to the ability of the kidneys to effectively excrete dietary potassium load in urine, while an increase in serum K⁺ is prevalent in patients with chronic kidney disease (CKD). Hyperkalaemia prevalence increases in more advanced CKD stages, and is associated with a poor prognosis. This scenario generates controversy on the correct nutritional approach to hyperkalaemia in CKD patients, considering the unproven link between potassium intake and serum K⁺ levels. Another concern is that drug-induced hyperkalaemia leads to the down-titration or withdrawal of renin-angiotensin system inhibitors (RASI) and mineralocorticoids receptors antagonists (MRA) in patients with CKD, depriving these patients of central therapeutic interventions aimed at delaying CKD progression and decreasing CV mortality. The new K⁺-binder drugs (Patiromer and Sodium-Zirconium Cyclosilicate) have proven to be adequate and safe therapeutic options to control serum K⁺ in CKD patients, enabling RASI and MRA therapy, and possibly, a more liberal intake of fruit and vegetables.

Keywords: chronic kidney disease; end-stage kidney disease; potassium.

Figure 1

Potassium intake recommended by guidelines (blue box) and body potassium distribution between intracellular (grey box) and extracellular fluid (green box). Graph illustrates internal (dashed blue box) and external (dashed orange box) potassium homeostasis. Colored boxes’ sizes are proportionate to potassium content.

Figure 2

Possible positive effects on serum K⁺ related to plant-dominant diet.