Glycogenosis Type V (McArdle’s Disease) with Hyperuricemia

Abstract

A 28-year-old male with glycogenosis type V associated with continuous hyperuricemia during mild daily activities is reported. An aerobic exercise test using a bicycle ergometer revealed that purine metabolites, i.e. ammonia, ino-sine, hypoxanthine and xanthine, were transiently increased by the exercise and that a subsequent increment in uric acid continued until the following day. The accelerated purine degradation by the muscle exercise was thus shown to be able to cause the overt hyperuricemia in a patient with glycogenosis type V. Therapeutic use of fructose for glycogenosis was disappointing due to fructose-induced hyperuricemia. A search for myogenic hyperuricemia is essential for therapeutic trials.

McArdle Disease and Exercise Physiology

“…This “emergency” mechanism for energy generation is blunted in healthy subjects. It has been shown that reliance on adenine nucleotide degradation during exercise leads to myogenic hyperuricemia in MD patients [21,22]. In addition, the reduction of hypoxanthine and xanthine to uric acid, which is catalyzed by xanthine oxidase, generates reactive oxygen species as a by-product; we recently found that MD patients experience elevated levels of oxidative stress [23].…”