Comparative analysis of bile acid spectrum in non-alcoholic fatty liver disease and cholelithiasis

Aim: Сomparative studying of changes in the spectrum of bile acids in bile in patients with nonalcoholic fatty liver disease and cholelithiasis.

Materials and methods: 140 patients were included in the survey: 50 - with nonalcoholic fatty liver disease and 90 - with cholelithiasis. The diagnosis of nonalcoholic fatty liver disease was established on the basis of ultrasound examination of the liver, the elasticity and fibrosis of liver by using the sonoelastography and liver biopsy. The prestone stage of cholelithiasis was established on the basis of ultrasound examination of the gallbladder and biochemical examination of bile. The level of total cholesterol, triglycerides, alanine aminotransferase, aspartate aminotransferase, total bilirubin, alkaline phosphatase and gamma glutamyl transpeptidase were studied using the analyzer "Labsystems" (Finland). The spectrum of bile acids in bile is studied by mass spectrometry on AmazonX apparatus (Bruker Daltonik GmbH, Bremen, Germany).

Results: Biochemical blood test revealed increase of cholesterol, triglycerides, cytolysis markers, and cholestasis, the most pronounced in patients with nonalcoholic fatty liver disease. Biochemical study of bile showed increase of cholesterol, decrease the total amount of bile acids and cholatecholesterol coefficient in the vesicle and hepatic bile in patients with nonalcoholic fatty liver disease and cholelithiasis. Mass spectrometry showed decrease the total amount of free bile acids (choloidal, chenodeoxycholic, deoxycholic) and increase the content of conjugated bile acids (glycocholic, glycodesoxycholic, taurocholic, taurodeoxycholic, ursodeoxycholic), the most pronounced in patients with nonalcoholic fatty liver disease.

Conclusion: Unidirectional changes in the spectrum of bile acids in nonalcoholic fatty liver disease and cholelithiasis give reason to believe that the trigger mechanism in the disturbance of bile acids metabolism is the liver. Reduction of primary bile acids, imbalance of phospholipids and cholesterol disrupt the stabilization of bile, resulting in unfavorable conditions in the bile ducts to form stones.