Abstract
Myogenic hyperuricemia is a novel type of secondary hyperuricemia that is caused by release of a large amount of purine metabolites from working skeletal muscles. Treatment of myogenic hyperuricemia in glycogenosis type V ( muscle phosphorylase deficiency ) or VII (muscle phosphofructokinase deficiency) is described.
1) Rest and restricted exercise: Bed rest gradually decreased blood uric acid, hypoxanthine and inosine in a patient with type VII glycogenosis.
2) Continuous glucose infusion: Bicycle-ergometer exercise caused an excessive increase in blood ammonia, hypoxanthine and uric acid in both patients with muscular glycogenosis type V and type VII. Intravenous infusion of glucose almost normalized this excessive increase in the patient with glycogenosis type V, while glucose infusion was ineffective in the patient with glycogenosis type VII. Since the glycolytic pathway is not impaired in glycogenosis type V, increased uptake and utilization of glucose following glucose infusion probably ameliorated excess purine degradation by improving muscular energy metabolism, and thus prevented the occurrence of myogenic hyperuricemia.
3) Allopurinol treatment: Allopurinol (300mg/day) was administered to the patient with glycogenosis type VII. The blood uric acid level was decreased from 15.0mg/dl to 5.1mg/dl after 2 weeks. Urinary uric acid excretion was also markedly decreased. On the other hand, urinary excretion of xanthine and hypoxanthine was increased by about 17 times and 4 times, respectively, but the total excreted purine level (sum of uric acid, xanthine and hypoxanthine)was decreased to about half. Blood and urinary purine levels are now satisfactorily controlled with 200mg/day of allopurinol.
