Differential Diagnosis of HyperCKemia

Abstract

AbstractElevated serum creatine kinase (CK) activity is usually an indicator of muscle damage. HyperCKemia is often an incidental finding and should be controlled after refraining from physical activity for some days, especially in asymptomatic patients. Furthermore, data from recent studies indicate that the upper limits of normal (ULN) need to be revised upward. This review includes an algorithm for the differential diagnosis of CK elevation in patients without muscular symptoms. In the field of neurology, in particular myopathies and neuropathies with affection of the lower motor neuron can cause symptomatic hyperCKemia, with CK values >1000 U/l (16,7 µkat/l) being indicative of a primary muscle disorder. Diseases with very high CK values include subtypes of muscular dystrophies, idiopathic inflammatory myopathies and metabolic myopathies. However, a normal or only slightly elevated CK value does not exclude the presence of a myopathy. The individual diagnostic procedure (e. g., muscle imaging, special laboratory studies, muscle biopsy and genetic testing) depends on the clinical phenotype and the results of electrophysiological studies. HyperCKemia can also be an adverse effect of several drugs including statins. In asymptomatic patients, statin-associated CK elevations <5 times the ULN can be tolerated. In patients with higher CK values and/or muscle symptoms, LDL-cholesterol lowering therapy should be changed. Rhabdomyolysis is a potentially life-threatening condition and is accompanied by highly elevated CK values. Acute phase treatment includes preserving renal function and restoring metabolic derangements.