Carnitine is a
vitamin-like substance that regulates lipid metabolism and energy production.
Carnitine homeostasis is mainly regulated by dietary intake and biosynthesis in the organs, including the skeletal muscle and the liver. Therefore, liver cirrhotic patients with reduced food intake,
malnutrition, biosynthetic disorder, and poor storage capacity of
carnitine in the skeletal muscle and liver are more likely to experience
carnitine deficiency. In particular, liver cirrhotic patients with
sarcopenia are at a high risk for developing
carnitine deficiency.
Carnitine deficiency impairs the important metabolic processes of the liver, such as gluconeogenesis,
fatty acid metabolism,
albumin biosynthesis, and
ammonia detoxification by the
urea cycle, and causes
hypoalbuminemia and
hyperammonemia.
Carnitine deficiency should be suspected in liver cirrhotic patients with severe malaise,
hepatic encephalopathy,
sarcopenia,
muscle cramps, and so on. Importantly, the blood
carnitine level does not always decrease in patients with
liver cirrhosis, and it sometimes exceeds the normal level. Therefore, patients with
liver cirrhosis should be treated as if they are in a state of relative
carnitine deficiency at the liver, skeletal muscle, and mitochondrial levels, even if the blood
carnitine level is not decreased. Recent clinical trials have revealed the effectiveness of
carnitine supplementation for the complications of
liver cirrhosis, such as
hepatic encephalopathy,
sarcopenia, and
muscle cramps. In conclusion,
carnitine deficiency is not always rare in
liver cirrhosis, and it requires constant attention in the daily medical care of this disease.
Carnitine supplementation might be an important strategy for improving the quality of life of patients with
liver cirrhosis.