A Novel Approach to Treatment of Hepatic Glycogen Storage Diseases: a Study Based on the Use of Uncooked Sweet Manioc Starch

A randomize and crossover study will be conducted on two consecutive days, comparing the use of classic cornstarch to the use of sweet manioc starch in patients with Glycogen Storage Disease type Ia. Ten patients diagnosed with Glycogen Storage Disease type Ia, confirmed by genetic analysis, will be included in the study. Sweet manioc starch and cornstarch, both of Brazilian origin, were analyzed in a previous study of the team in the artificial gastrointestinal model (TIM-1). They will be supplied uncooked, in the same way that cornstarch is currently used in the treatment of hepatic Glycogen Storage Diseases. Doses administered to patients will be 100 g of starch diluted in 200 ml of water at room temperature. To carry out the study, the patients will remain two consecutive nights in the hospital. They will remain in their normal diet until the administration of the starches at 22 hours. To perform the test, at 10 pm blood collection will be performed and after that the patient will ingest the starch (cornstarch or sweet manioc starch, determined by previous randomization). In sequence, blood collection will be performed every hour until the patient has a serum glucose value below 70mg/dL or after the patient stays 10h in a fast. Afterwards, the patient will return to his usual diet until the next test at 22 hours. The same procedures will be performed on the second night, the only change will be the starch used, and if the patient ingested uncooked cornstarch the first night, the same night will ingest the sweet manioc starch, or the opposite.If the patient has hypoglycaemia during the study, it will be discontinued.