Metabolic alkalosis is commonly associated with which electrolyte disturbance?

• A. Hyperkalemia
• B. Hyponatremia
• C. Hypokalemia
• D. Hypercalcemia

Answer: (C)

Potassium balance and acid–base status are closely linked. In metabolic alkalosis, a common accompanying change is low potassium (hypokalemia). Loss of hydrogen ions or gain of bicarbonate often occurs with volume depletion (for example, from vomiting or diuretics). The kidneys respond by increasing sodium reabsorption, and potassium (and hydrogen) are secreted in the distal nephron under aldosterone influence. This renal potassium loss, along with the tendency for potassium to shift into cells at higher pH, lowers serum potassium. So hypokalemia is the typical electrolyte disturbance seen with metabolic alkalosis, while hyperkalemia, hyponatremia, or hypercalcemia are not characteristic associations.