Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (855 page)

   Serum creatine levels may be significantly increased in amyotrophic lateral sclerosis, dermatomyositis, myasthenia gravis, starvation, muscular dystrophies, and trauma. Creatine synthesis is stimulated by methyltestosterone and may also be increased in hyperthyroidism, diabetic acidosis, and puerperium.

   This test is rarely used clinically.

   Interpretation

Increased In

   High dietary intake (meat)

   Destruction of muscle

   Hyperthyroidism (this diagnosis is almost excluded by normal serum creatine)

   Active RA

   Testosterone therapy

Decreased In

   Not clinically significant

   Drugs (e.g., TMP/SMX, cimetidine, cefoxitin)

   Limitations

   Artifactual decrease in DKA

CREATINE KINASE (CK), TOTAL
*

   Definition