Question

Why will a patient with Systemic Carnitine deficiency experience repeated episodes of hypoglycemia?

Answer 1

Carnitine acyltransferase is a carrier protein that catalyzes the transport the long chain fatty acids across the mitochondria; it needs the cofactor known as carnitine for its functioning. It is the rate-limiting step in the beta-oxidation of fatty acids. So, the deficiency of carnitine reduces the fatty acid transport into the mitochondria, which in turn decreases the rate of beta-oxidation. Beta-oxidation is the primary source of energy supply when the glycogen levels decrease.

During fasting and exercise, the symptoms of hypoglycemia worsening due to the increased demand of carnitine. Beta oxidation is necessary during the exercise and fasting to supply the energy. But the lack of carnitine reduces the rate of beta-oxidation and causes hypoglycemia.