THE MEASUREMENT of serum enzyme activities, particularly those of creatine phosphokinase (CPK), aldolase, and glutamic oxaloacetic transaminase (SGOT), is an important adjunct in the diagnosis of primary muscle disease.1-4 Elevations have been found in patients with muscular dystrophy and polymyositis,5-7 whereas patients with neurogenic atrophy generally have had normal levels.8
Altered potassium metabolism has long been associated with muscle dysfunction,9 but only a few references have appeared linking hypokalemia, myopathy, and serum enzyme elevation.10-12 Three patients with hypokalemia and severe muscle weakness were studied; all had marked alterations in their serum enzymes, particularly CPK.
Methods
Creatine phosphokinase determinations were done using the method of Nielsen and Ludvigsen.13 The normal range is 0μU to 18μU per milliliter.Glutamic oxaloacetic transaminase determinations were performed using a modification of the method of Henry and co-workers.14 The normal values are in the range of