In a patient with marked hyperglycemia, after insulin therapy and normalization of glucose, which potassium level is most expected?

In a patient with marked hyperglycemia, after insulin therapy and normalization of glucose, which potassium level is most expected?

• A. 4.8 mmol/L
• B. 4.6 mmol/L
• C. 4.4 mmol/L
• D. 4.2 mmol/L

Answer: (D)

Insulin drives potassium into cells, so correcting hyperglycemia with insulin causes the extracellular potassium to fall. Even though total body potassium is often depleted, the serum level shifts downward as K moves intracellularly. After glucose normalizes, you typically see a fall toward the low end of the normal range, which is why the option reflecting the lowest value here (4.2 mmol/L) is most expected. In clinical practice, this means closely monitoring potassium and providing replacement as needed to prevent hypokalemia and related complications.

Insulin drives potassium into cells, so correcting hyperglycemia with insulin causes the extracellular potassium to fall. Even though total body potassium is often depleted, the serum level shifts downward as K moves intracellularly. After glucose normalizes, you typically see a fall toward the low end of the normal range, which is why the option reflecting the lowest value here (4.2 mmol/L) is most expected. In clinical practice, this means closely monitoring potassium and providing replacement as needed to prevent hypokalemia and related complications.