Effect of hypocalcemia on muscle in disorders of calcium metabolism.

We reported on three hypocalcemic patients with various serum creatine kinase (CK) levels and Ca metabolic disorders. Two patients with moderate hypocalcemia had increased CK levels (hyper-CK-emia), which normalized during treatment for the hypocalcemia; a negative correlation between the Ca and CK levels was observed in both patients. The remaining patient with mild hypocalcemia had a normal CK level. We discuss the effect of hypocalcemia on muscle in our patients as well as previously reported patients. Muscle may respond to hypocalcemia in three stages, namely homeostatic, asymptomatic hyper-CK-emic and myopathic stages.