Hypokalemic paralysis in a professional bodybuilder.

Severe hypokalemia is a potentially life-threatening disorder and is associated with variable degrees of skeletal muscle weakness, even to the point of paralysis. On rare occasions, diaphragmatic paralysis from hypokalemia can lead to respiratory arrest. There may also be decreased motility of smooth muscle, manifesting with ileus or urinary retention. Rarely, severe hypokalemia may result in rhabdomyolysis. Other manifestations of severe hypokalemia include alteration of cardiac tissue excitability and conduction. Hypokalemia can produce electrocardiographic changes such as U waves, T-wave flattening, and arrhythmias, especially if the patient is taking digoxin. Common causes of hypokalemia include extrarenal potassium losses (vomiting and diarrhea) and renal potassium losses (eg, hyperaldosteronism, renal tubular acidosis, severe hyperglycemia, potassium-depleting diuretics) as well as hypokalemia due to potassium shifts (eg, insulin administration, catecholamine excess, familial periodic hypokalemic paralysis, thyrotoxic hypokalemic paralysis). Although the extent of diuretic misuse in professional bodybuilding is unknown, it may be regarded as substantial. Hence, diuretics must always be considered as a cause of hypokalemic paralysis in bodybuilders.