In general , markers for cholesterol absorption and synthesis displayed reciprocal patterns , showing that cholesterol metabolism is tightly regulated by the interplay of intestinal absorption and endogenous synthesis .
Distinctive patterns for cholesterol absorption or cholesterol synthesis could be identified , suggesting that metabolic disorders can be classified as ' cholesterol absorbers or cholesterol synthesizers ' .
Non-cholesterol sterols are vali date d biomarkers for intestinal cholesterol absorption and endogenous cholesterol synthesis .
However , their use in metabolic disturbances has not been systematic ally explored .
Therefore , we conducted a systematic review to provide an overview of non-cholesterol sterols as markers for cholesterol metabolism in different metabolic disorders .
Serum 27-hydroxycholesterol in patients with primary biliary cirrhosis suggests alteration of cholesterol catabolism to bile acids via the acidic pathway.
Reduced cholesterol synthesis has been reported in patients with primary biliary cirrhosis but no data are available on changes in cholesterol catabolism induced by the disease . Serum levels of 7alpha-hydroxycholesterol and 27-hydroxycholesterol  have been measured in 25 patients ( either normocholesterolemic or hypercholesterolemic ) with primary biliary cirrhosis and in control subjects . To evaluate cholesterol synthesis , serum levels of lathosterol were measured , and campesterol and sitosterol were considered to reflect intestinal absorption and biliary elimination of sterols . In normocholesterolemic patients with primary biliary cirrhosis , lathosterol was significantly lower than in normocholesterolemic controls ( P < 0.05 ) whereas no difference was found between hypercholesterolemic patients and hypercholesterolemic controls . Serum concentrations of sitosterol were significantly higher in both normocholesterolemic and hypercholesterolemic patients with primary biliary cirrhosis as compared with the respective controls ( P < 0.01 ) . In patients with primary biliary cirrhosis , serum 7alpha-hydroxycholesterol was slightly higher than in controls . 27-Hydroxycholesterol was significantly higher in hypercholesterolemic compared to normocholesterolemic controls ( P < 0.05 ) and a significant linear correlation ( r = 0.771 ; P < 0.001 ) was found between 27-hydroxycholesterol and cholesterol . In contrast , in patients with primary biliary cirrhosis , high cholesterol concentrations were not associated with increased serum levels of 27-hydroxycholesterol . Our data confirm that in patients with primary biliary cirrhosis , cholesterol synthesis and biliary elimination of sterols are impaired and also suggest that both the feedback regulation of retained bile acids on cholesterol 7alpha-hydroxylase and the scavenger effect on elevated serum cholesterol by cholesterol 27-hydroxylase are deficient in these patients . acids via the acidic pathway
In general , markers for cholesterol absorption and synthesis displayed reciprocal patterns , showing that cholesterol metabolism is tightly regulated by the interplay of intestinal absorption and endogenous synthesis .
Distinctive patterns for cholesterol absorption or cholesterol synthesis could be identified , suggesting that metabolic disorders can be classified as ' cholesterol absorbers or cholesterol synthesizers ' .
Non-cholesterol sterols are vali date d biomarkers for intestinal cholesterol absorption and endogenous cholesterol synthesis .
However , their use in metabolic disturbances has not been systematic ally explored .
Therefore , we conducted a systematic review to provide an overview of non-cholesterol sterols as markers for cholesterol metabolism in different metabolic disorders .