Sweat electrolytes in glycogen storage disease, type I.

The cause of high concentration of electrolytes in sweat in a small group of patients with glycogen storage disease has interested us. Sodium and chloride concentration in sweat of three boys with glucose-6-phosphatase deficiency has been found in a range comparable to that seen in patients with cystic fibrosis of the pancreas. These children seem to have a preference for salty food and also have frequent periods of hypoglycemia. While such factors have been known to influence the sweat test, heretofore such association in patients with glycogen storage has not been recorded. Table I presents data on five children with glycogen storage disease type I. Significantly high electrolyte concentrations in sweat were found in one male, moderately high concentrations in two males, and normal concentrations in the two females. Two males with phosphorylase defect had normal electrolyte concentrations. Sweat tests by pilocarpine iontophoresis were done by the method of Gibson and Cooke on 484 children between the ages of 4 weeks and 5 years. Collections were made on the left forearm, usually for less than 60 minutes. As shown in Table II, 73 of the tests were on children with cystic fibrosis (CF) and eight on children with glycogen storage disease. The remaining 403 tests included 84 on CF siblings and other relatives of children with CF. Since no difference was discernible between results of tests on these relatives and other normal individuals, they were grouped together as controls. Among normal individuals, sodium, and chloride values in sweat were below 30 meq/1 in 96%. A few patients with cystic fibrosis or glycogen storage disease had values in the borderline range of 40-49 meq/l. All the males with glucose-6-phosphatase deficiency had values above 50 meq/l.