Abbreviations and Acronyms:ASDN (aldosterone-sensitive distal nephron), CKD (chronic kidney disease), DCT (distal convoluted tubule), DCT1 (proximal portion of the distal convoluted tubule), DCT2 (distal portion of the distal convoluted tubule), ENaC (epithelial Na+ channel), KS (kidney specific), NCC (NaCl cotransporter), NHANES (National Health and Nutrition Examination Survey), RAAS (renin-angiotensin-aldosterone system), ROMK (renal outer medullary K+), WNK (with no lysine family of kinases), WNK1 (WNK lysine-deficient protein kinase 1), WNK4 (WNK lysine-deficient protein kinase 4)
- ▪Over several million years, physiology and metabolism of humans evolved to retain Na+ and excrete K+ in response to a diet that was low in Na+ and high in K+. With the onset of agriculture and industrialization, there has been a precipitous drop in dietary K+ consumption and an equal rise in dietary salt consumption, contributing to disease onset. This is further supported by the fact that the newest Dietary Guidelines for Americans have listed K+ as a “nutrient of public health concern” because of its inadequate consumption. Low K+ intake is then implicated in various chronic diseases including hypertension, cardiovascular disease, osteoporosis, and nephrolithiasis.
- ▪The ability to maintain K+ homeostasis in the setting of high dietary intake is regulated by the normal kidney. In addition to the well-recognized role of aldosterone in renal K+ secretion, recent findings have identified the presence of an enteric K+ sensing mechanism that can initiate the renal secretory process upon K+ entry into the gastrointestinal tract. In addition, the distal convoluted tubule has been identified as a K+ sensor capable of initiating K+ exertion independent of mineralocorticoid activity.
- ▪Increased dietary K+ intake has been linked to various health benefits including decreased blood pressure, reduced risk of stroke, improved bone health, and a reduction in the risk of renal stone disease. At the same time, drugs used to treat hypertension result in increased K+ concentrations, requiring dietary restriction of K+-enriched foods.
- ▪A plant-based (K+-enriched) diet offers benefits that include reduced phosphorus absorption and improvement in metabolic acidosis. A limitation of such a diet can be the development of hyperkalemia in patients with impaired renal K+ excretion.
- ▪New drugs designed to bind K+ in the gastrointestinal tract are now available. These drugs have been shown to be effective in maintaining normokalemia in the setting of ongoing use of blockers of the renin-angiotensin-aldosterone system in patients previously intolerant of these drugs due to hyperkalemia. These drugs may allow patients to liberalize their diets so as to receive the benefits of a K+-enriched diet without development of hyperkalemia.
Overview of Renal K+ Handling
Distal Tubule as a K+ Sensor
Enteric Sensing of K+ Intake
Clinical Benefits of K+ Supplementation
Use of K+-Enriched Diet in Chronic Kidney Disease
Control of Metabolic Acidosis
Management of Hyperkalemia
- Bakris G.L.
- Pitt B.
- Weir M.R.
- et al.
Effect of patiromer on serum potassium level in patients with hyperkalemia and diabetic kidney disease: the AMETHYST-DN randomized clinical trial.
- Kosiborod M.
- Rasmussen H.S.
- Lavin P.
- et al.
Implementation of K+-Enriched Diets in Patients at Risk for Hyperkalemia
Supplemental Online Material
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