The presence of serum creatine kinase 2 (MB) in acromegalic myopathy.

Increase in size of bone is characteristic of acromegaly. In addition, hypertrophy of other tissues including skeletal muscle and associated myopathy may occur. We recently found 10 U/1 of isoenzyme creatine kinase 2 (MB) or 10.9% of total creatine kinase in a patient with acromegaly who did not show clinical or laboratory evidence of acute myocardial necrosis. The myopathy associated with acromegaly is thus another cause for the presence of serum CK 2 (MB), and CK 2 (MB) is not a specific isoenzyme for myocardial damage since it may be identified in the serum of patients with skeletal muscle conditions.