Table 2.

Causes of elevated creatinine kinase other than active idiopathic inflammatory myopathy

Muscle trauma

  • crush injury

  • needle stick

  • EMG

  • surgery

  • convulsions, delirium tremens

Diseases affecting muscle

  • myocardial disease eg infarction

  • rhabdomyolysis

  • metabolic or mitochondrial myopathies

  • muscular dystrophy

  • infectious myositis

  • muscle denervation, eg amyotrophic lateral sclerosis

  • myopathy associated Ryanodine receptor 1 (RYR1) gene mutations

Drug/toxin-induced myopathy

  • lipid-lowering agents, especially HMG-CoA-reductase inhibitors

  • alcoholic myopathy

  • drugs of abuse, eg cocaine, amphetamines, phencyclidine

  • malignant hyperthermia and neuroleptic malignant syndrome

  • other medications, eg zidovudine, colchicine, chloroquine, ipecac, barbiturates, morphine, diazepam

Drug-induced myositis

  • D-penicillamine

  • interferon

Endocrine and metabolic abnormalities

  • hypothyroidism

  • hypokalemia

  • hypocalcaemia

  • hyperosmolar state or ketoacidosis

  • diabetic nephrotic syndrome with oedema

  • renal failure

Elevation of CK–BB

  • CNS disease

  • tumours (GI, bronchial, other)

Elevation without disease

  • strenuous, prolonged, and/or unaccustomed exercise

  • ethnic group (black>white)

  • increased muscle mass

  • macro-CK

  • idiopathic

  • CK = creatinine kinase; CNS = central nervous system; EMG = electromyography; GI = gastrointestinal

  • Adapted from Targoff IN. Rheum Dis Clin North Am 2002;28:859–90.