Which electrolyte abnormality is typical in primary adrenal insufficiency?

Which electrolyte abnormality is typical in primary adrenal insufficiency?

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

Answer: (A)

In primary adrenal insufficiency, there is a deficiency of aldosterone as well as cortisol. Aldosterone normally promotes sodium reabsorption and potassium excretion in the distal nephron. When aldosterone is deficient, the kidney wastes sodium, leading to low serum sodium and volume depletion. Cortisol deficiency can drive increased ADH release, causing more water reabsorption and a dilutional drop in sodium. The net result is hyponatremia, which is a typical electrolyte pattern in this condition. Hyperkalemia can occur because potassium excretion is impaired, but hyponatremia is the most consistently observed abnormality. Hypernatremia would be unlikely due to sodium loss, and hypokalemia would contradict the expected effect of aldosterone deficiency.

In primary adrenal insufficiency, there is a deficiency of aldosterone as well as cortisol. Aldosterone normally promotes sodium reabsorption and potassium excretion in the distal nephron. When aldosterone is deficient, the kidney wastes sodium, leading to low serum sodium and volume depletion. Cortisol deficiency can drive increased ADH release, causing more water reabsorption and a dilutional drop in sodium. The net result is hyponatremia, which is a typical electrolyte pattern in this condition. Hyperkalemia can occur because potassium excretion is impaired, but hyponatremia is the most consistently observed abnormality. Hypernatremia would be unlikely due to sodium loss, and hypokalemia would contradict the expected effect of aldosterone deficiency.