Potassium and the kidney

In the past decade, understanding of the mechanisms by which the kidneys sense dietary potassium imbalance and affect the cardiorenal system has substantially advanced. These mechanisms explain why low-potassium diets promote salt-sensitive hypertension, whereas potassium-rich diets enhance natriuresis and lower blood pressure. Increasing dietary potassium may therefore be an effective strategy to reduce cardiovascular disease risk. Clinical trials have shown that replacing regular salt with potassium-enriched substitutes lowers blood pressure and reduces cardiovascular events and mortality. Emerging evidence suggests that low dietary potassium intake contributes to kidney injury, and low urinary potassium excretion is associated with accelerated chronic kidney disease (CKD) progression. However, whether the cardiorenal benefits of adequate potassium intake in CKD outweigh the risk of hyperkalaemia remains uncertain. A clearer understanding of the relationship between dietary potassium intake and blood potassium levels, as well as the optimal blood potassium range for kidney and cardiovascular health, is needed to resolve this question. New strategies to mitigate hyperkalaemia, including use of potassium binders and various kidney-protective drugs, could enable people with CKD to safely consume a potassium-rich diet and avoid the need to discontinue use of medications that increase the risk of hyperkalaemia, such as renin–angiotensin–aldosterone inhibitors and mineralocorticoid receptor antagonists.