Glycogen Storage Disease has been divided into at least 10 different types based on the deficiency of a particular enzyme which controls blood sugar levels.

Type I Glycogen Storage Disease is a deficiency of the enzyme glucose -6 - phosphatase which helps in maintaining a normal blood glucose (sugar concentration) during fasting. Patients with this particular disorder show a large number of abnormalities which exhibit themselves in growth failure, a greatly enlarged liver, and a distended (swollen) abdomen. The abnormal blood chemical condition is indicated by low blood sugar concentration and higher than normal levels of lipids and uric acid.

In the past, these patients have been treated by frequent feedings during the daytime and occasional feedings during the normal sleeping hours which required waking the patient. This was the accepted form of therapy until 1966 to 1967, but the patients continued to show various difficulties in physical development and blood chemistry.

Starting in 1967, surgeons began performing a surgical procedure, called a portacaval shunt, which bypassed the blood around the liver. In some patients this procedure resulted in improvement in observable physical condition and improved biochemical levels in the blood. In 1974 it was found that patients also did exceedingly well if the blood glucose level was maintained within the normal range by frequent daytime feedings and by continuous infusion of a solution high in glucose concentration into the stomach during the night. Maintenance of the blood glucose level either in total intravenous feedings or by continuous infusion of high glucose-containing foods into the stomach could reverse all of the physical and chemical signs of this disease.

A practical management technique for maintaining the blood glucose level has been devised in which a naso-gastric tube is inserted into the stomach each evening and through this tube is infused a solution containing a high concentration of glucose so the blood sugar level remains between 75 and 120. In the daytime the tube is removed and the patient eats a high starch feeding approximately every 2-1/2 to 3-1/2 hours. Using this technique, most of the physical and biochemical abnormalities are completely reversed.

One study in which a total of 14 patients were followed, nine for a period of greater than 5 years, has shown this to be an effective form of treatment. Although younger children will have to use the tube each evening, doctors feel that this may not be necessary past puberty.