Increased plasma uric acid after exercise in muscle phosphofructokinase deficiency

Type VII glycogenosis (muscle phosphofructokinase deficiency) is attended by hyperuricemia and hyperuricosuria. In one patient, we found that exercise on a bicycle ergometer increased plasma uric acid, inosine, and hypoxanthine levels. Forearm exercise also markedly increased venous inosine, hypoxanthine, and ammonia in the exercising arm of two patients. Exaggerated release of precursors for uric acid synthesis from exercising muscle may be related to the hyperuricemia.