How can carbohydrate metabolism disorders cause low blood sugar and liver enlargement?

Disorders of carbohydrate metabolism, particularly glycogen storage diseases (GSD), cause low blood sugar and liver enlargement through the disruption of normal glucose regulation.12

Mechanisms of Disease

• Hypoglycemia: The liver acts as a primary reservoir for glucose, storing it as glycogen to be released during fasting or periods of high energy demand. When enzymes required for glycogen degradation are deficient, the liver cannot effectively break down stored glycogen into glucose to maintain blood sugar levels, leading to hypoglycemia.13
• Liver Enlargement: Because the metabolic pathways for breaking down glycogen are blocked, glycogen accumulates within the liver cells. This buildup causes the organ to swell, a condition known as hepatomegaly.132

Similar symptoms can occur in disorders of gluconeogenesis, where the body is unable to manufacture glucose from non-carbohydrate sources, further impairing the body's ability to maintain stable blood sugar levels during fasting. While these conditions can be serious, they are often managed through dietary interventions, such as frequent feedings of carbohydrates or slow-release glucose, to ensure a constant supply of energy.145