A case of hypokalemic perodic paralysis induced by hyperinsulinemia / 대한내과학회지

ABSTRACT

Hypokalemia periodic paralysis, a clinical syndrome characterised by systemic weakness and low serum potassium, is a rare but treatable cause of acute weakness. Attacks of flaccid paralysis can be associated with hypokalemia triggered by insulin. Insulin reduce the conductance of the inward rectifier K+ channel for outward-flowing currents. Therefore, insulin potentiates depolarization of hypokalmeic periodic paralysis. We have experienced a case of hypokalemic periodic paralysis induced by hyperinsulinemia in 38-year old man, with complaint of intermittent paralysis of extremities. On admission, serum K+ was 2.1 mEq/L. He was no family history of muscle weakness. Thyroid function was normal. Serum levels of aldosterone, renin and cortisol were normal. Random plasma glucose level was 129 mg/dL and serum insulin was 131 uIU/mL. Shortly after intravenous supplementation of potassium, muscle weakness was improved. Oral glucose tolerance test revealed impaired glucose tolerance and hyperresponse of insulin and phosphate.