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Insulin Potassium Effect — FRCA Primary MCQ

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HardPhysiology - Endocrine & MetabolicInsulin Potassium EffectFRCA Primary

Insulin–glucose therapy is given for hyperkalaemia. Which observation most accurately describes the effect on total-body potassium?

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Correct answer: C — Plasma potassium falls through cellular redistribution without net potassium removal

The best answer is “Plasma potassium falls through cellular redistribution without net potassium removal”. Insulin stimulates Na+/K+-ATPase activity, especially in muscle, shifting potassium into cells and lowering plasma concentration within minutes. It does not remove potassium from the body, so definitive treatment may require renal excretion, gastrointestinal removal or dialysis. The effect is temporary and must be monitored alongside glucose administration.

Reference: RCoA, Primary FRCA syllabus: https://www.rcoa.ac.uk/sites/default/files/documents/2026-01/Primary-FRCA-Syllabus.pdf; Canonical and alternative pathways of GLUT4 recruitment: https://pmc.ncbi.nlm.nih.gov/articles/PMC13116035/