*1.2.1 Nutritional factors*

Malnutrition influences on liver function in children with cystic fibrosis. Children with diagnosed cystic fibrosis and liver damage have lower body mass, height, circumference of the upper arm, and BMI. Patients with cystic fibrosis also have significantly lower levels of linoleic (LA), docosahexaenoic (DHA), and docosapentaenoic (DPA) acids. The influence of parenteral nutrition and antioxidant and vitamin deficiency is confirmed [26–29]. Sometimes in children with cystic fibrosis especially with meconium ileus, total parenteral nutrition is necessary. Total parenteral nutrition (TPN) therapy is a well-recognized cause of liver injury. The histologic changes attributed to TPN in the literature vary widely. Total parenteral nutritioninduced liver disease develops in 40–60% of infants who require long-term TPN. The clinical spectrum includes cholestasis, cholelithiasis, hepatic fibrosis with progression to biliary cirrhosis, and the development of portal hypertension and liver failure in a significant number of children who are totally parenterally fed. The pathogenesis is multifactorial and is related to prematurity, low birth weight, and duration of TPN. The degree and severity of the liver disease are related to the recurrent sepsis including catheter sepsis, bacterial translocation, and cholangitis. The lack of enteral feeding leading to reduced gut hormone secretion, reduction of bile flow, and biliary stasis may be important mechanisms in the development of cholestasis, biliary sludge, and cholelithiasis.
