The kidneys are responsible for filtering potassium, and certain kidney diseases and treatments can have a direct effect on potassium levels. Potassium is needed for muscle contractions and regulating heartbeat; critically low levels can be a medical emergency and even result in death. Symptoms of low potassium include nausea, vomiting, constipation, numbness, tingling, fainting and mental disturbances. If you are suffering from kidney disease, it is important to pay attention to the signs and symptoms of low potassium.
Renal Tubular Acidosis
Low potassium is called hypokalemia and refers to serum potassium below 3.5 milliequivalents per liter of blood. Major functions of the kidneys include reabsorbtion of potassium and performing compensatory mechanisms to sustain acid-base balance in the body. In renal tubular acidosis, the kidneys attempt to correct for an acidic environment, and, as a result, excess potassium is excreted into the urine. If hypokalemia results, treatment includes administering sodium bicarbonate or sodium citrate to correct acidosis.
Potassium-Depleting Diuretics
Fluid retention is a common problem in kidney disease. If potassium-depleting diuretics are used to remove excess fluid, however, at any stage of kidney disease, low potassium can occur. Potassium-depleting diuretics include chlorthizasde and hydrochlorithizide, and are collectively referred to as thiazide diuretics. Hypokalemia is not common in patients with late stages of kidney disease; potassium-depleting diuretics are not commonly prescribed.
Hormonal Causes of Low Potassium
Aldosterone is a hormone secreted by the adrenal glands, which are located on top of the kidneys. This hormone acts on the kidneys to increase sodium and water reabsorption into the body and to increase potassium secretion into the urine. Hyperaldosteronism, defined as overproduction of aldosterone by the adrenal glands, increases aldosterone production, which leads to low serum potassium due to increased excretion in the urine. This could result in hypokalemia.
Managing Kidney Disease and Potassium
Supplementation with potassium or increasing intake of high potassium fruits can correct hypokalemia. However, compromised kidney function is a serious medical condition, and trying to correct levels on your own could be detrimental to your health. Management of kidney disease and potassium levels should only be done by a qualified physician, such as a board-certified nephrologist.
References
- "Archives of Internal Medicine"; "Diuretic Regimens in Essential Hypertension"; J. Licht et al; September 1983
- "Nutrition Therapy and Pathology"; Marcia Nelms et al; 2007
- National Kidney Foundation: K/DOQI Clinical Practice Guidelines on Hypertension and Antihypertensive Agents in Chronic Kidney Disease
