Summary:
Obesity, diabetes mellitus type 2 and dyslipidemia, characterized by hypertriglyceridemia and low
HDL-cholesterol levels, are risk factors for cholesterol gallstone disease. The common denominator of
above-mentioned states is insulin resistance. Hypolipidemic treatment significantly influences not only
the biliary lipid composition, but also other etiopathogenetic mechanisms of the disease. Three principal
defects are involved in gallstone formation – cholesterol supersaturation, accelerated nucleation, and
gallbladder dysmotility. The degree of cholesterol saturation in gallbladder bile is the most important
predictor of cholesterol crystal formation. Cholesterol, lecithin and bile acids are the major components
in bile. According to the molar ratios of the three main components, simple or mixed micelles, unstable
unilamellar or multilamellar vesicles are formed in the bile. The cholesterol supersaturation of the gallbladder
bile and cholesterol crystal formation from the unstable multilamellar vesicles initiates the onset
of cholesterol cholelithiasis. The pool of unesterified cholesterol is the source for VLDL synthesis; together
with HDL-cholesterol, it is also the source for cholesterol secretion into the bile. The main metabolic
products of cholesterol degradation are bile acids, which are synthesized predominantly from
LDL-cholesterol. The rate of the production of primary bile acids is principally regulated by cholesterol
7α-hydroxylase (CYP7A1). The treatment of dyslipidemia with niacin and resins does not influence the
saturation of bile with cholesterol or the incidence of cholelithiasis. The effects of ezetimibe in human
patients with the respect of cholesterol cholelithiasis have not been published. The fibrate treatment is
associated with increased cholesterol saturation of bile due to inhibition of CYP7A1 activity, enhanced flux of cholesterol via HDL and increased secretion of cholesterol into bile. The clinical studies describe
cholesterol supersaturation in bile and increased frequency of cholelithiasis as well. The administration
of pravastatin and simvastatin led to reduced cholesterol saturation indexes. The patients with endogenous
hypertriglyceridemia and low HDL-cholesterol being administered with polyunsaturated fatty
acids of n-3 family had decreased cholesterol concentration in bile. Other authors described beneficial
effect of fish oil on the biliary cholesterol nucleation time, improvement of gallbladder sensitivity to cholecystokinin
and the prevention of cholesterol gallstone formations caused by rapid weight loss.
Key words:
cholesterol cholelithiasis, dyslipidemia, secretion of bile lipids, bile saturation with cholesterol,
risk of cholelithiasis, hypolipidemic treatment.
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