Cori-Forbes disease or type III glycogenosis is an inherited disease caused by a deficiency of the debranching enzyme, causing a defect in the production of glucose from glycogen in the liver and sometimes in muscle. The symptoms are hepatomegaly, fasting hypoglycaemia, and in some patients (type IIIa) muscle damage (fatigue, intolerance to exertion, cardiomyopathy, etc.). Its treatment is largely based on dietary management: food intake at strict times, every three to four hours, high carbohydrate diet during infancy, then high protein to promote gluconeogenesis from amino acids.
Phenotype-dependent effects
Fatty acids may constitute another alternative fuel. A few case reports in the past have documented the beneficial effects of the ketogenic diet, which is high in fat and low in carbohydrates, in type III glycogenosis. A clinical trial in the Netherlands tested the effects of consuming drinks high in ketones before exercise. Six patients were included. One week apart, they followed two protocols: taking a drink rich in carbohydrates (66 g of maltodextrin) followed by two exercise sessions (pedaling 15 minutes in a standing position then 10 minutes in a lying position in an MRI machine), and taking a drink containing 30 g of maltodextrin and 395 mg / kg of ketones, followed by the same exercises. Ingestion of the ketone-rich drink resulted in:
- acute nutritional ketosis in all six participants;
- a variation in blood sugar twice as large, with an average glycemic delta of 2.6 mmol / L versus 4.7 mmol / L for the drink containing only maltodextrin, each of the participants having also remained normoglycemic throughout the whole sessions;
- lower insulinemia at 50 min and 105 min;
- better energy metabolism of the quadriceps, evaluated by imaging (NMR spectroscopy of phosphorus 31) for three of the six participants with severe muscle phenotype.
