Hypoparathyroidism and elevated muscle enzymes

We studied a patient with hypocalcemia and increased serum activity of sarcoplasmic enzymes. Idiopathic hypoparathyroidism was established by history, low serum parathyroid hormone content, and marked responsiveness of urinary cyclic AMP and phosphate to parathyroid hormone. Muscle-associated isoenzymes of creatine phosphokinase and lactic dehydrogenase were increased, but there was no concomitant muscle weakness. Muscle biopsy was normal by morphologic and histochemical examination. The patient was treated with calcium and vitamin D. As the calcium rose, there were corresponding decreases in the serum activities of creatine phosphokinase and lactic dehydrogenase, with correlation coefficients of -0.88 and -0.64, respectively (p less than 0.01).