Development of minimally invasive 13 C-glucose breath test to examine different exogenous carbohydrate sources in patients with glycogen storage disease type Ia

• Published in: Molecular genetics and metabolism reports 2022-06, Vol.31, p.100880
• Main Authors: Turki, Abrar, Stockler, Sylvia, Sirrs, Sandra, Salvarinova, Ramona, Ho, Gloria, Branov, Jennifer, Rosen-Heath, Annie, Bosdet, Taryn, Elango, Rajavel
• Format: Article
• Language: English
• ISSN: 2214-4269; 2214-4269

Glycogen storage disease type Ia (GSD Ia) is an autosomal recessive disorder caused by deficiency of glucose-6-phosphatase (G6Pase), resulting in fasting hypoglycemia. Dietary treatment with provision of uncooked cornstarch (UCCS) or a novel modified cornstarch ( ) is available to treat hypoglycemia, yet choice of carbohydrate to achieve a desirable glycemic control is debated. C-glucose breath test ( C-GBT) can be used to examine glucose metabolism from different carbohydrate sources via CO in breath. Our objectives were: 1) establishing the use of a minimally invasive C-GBT to examine in vivo glucose metabolism in healthy adults, and 2) using C-GBT to measure utilization of the standard UCCS vs. in GSD Ia and healthy controls. Ten healthy adults (6F: 4 M, 22-33y) underwent C-GBT protocol twice as a proof-of-principle, once with oral isotope dose (glucose 75 g + [U- C ] d-glucose 75 mg) and once without isotope (only glucose 75 g) to test sensitivity of natural C-enrichment. Breath samples were collected at baseline and every 20 min for 240 min. Rate of CO production was measured at 120 min using indirect calorimetry. Finger-prick blood glucose was measured using a glucometer hourly to test hypoglycemia (glucose