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 .
Plasma sterol evidence for decreased absorption and increased synthesis of cholesterol in insulin resistance and obesity.
BACKGROUND The rise in LDL with egg feeding in lean insulin-sensitive ( LIS ) participants is 2- and 3-fold greater than in lean insulin-resistant ( LIR ) and obese insulin-resistant ( OIR ) participants , respectively . OBJECTIVE We determined whether differences in cholesterol absorption , synthesis , or both could be responsible for these differences by measuring plasma sterols as indexes of cholesterol absorption and endogenous synthesis . DESIGN Plasma sterols were measured by gas chromatography-mass spectrometry in a r and om subset of 34 LIS , 37 LIR , and 37 OIR participants defined by the insulin sensitivity index ( S(I ) ) and by BMI criteria selected from a parent group of 197 participants . Cholestanol and plant sterols provide a measure of cholesterol absorption , and lathosterol provides a measure of cholesterol synthesis . RESULTS The mean ( ±SD ) ratio of plasma total absorption biomarker sterols to cholesterol was 4.48 ± 1.74 in LIS , 3.25 ± 1.06 in LIR , and 2.82 ± 1.08 in OIR participants . After adjustment for age and sex , the relations of the absorption sterol-cholesterol ratios were as follows : LIS > OIR ( P < 0.001 ) , LIS > LIR ( P < 0.001 ) , and LIR > OIR ( P = 0.11 ) . Lathosterol-cholesterol ratios were 0.71 ± 0.32 in the LIS participants , 0.95 ± 0.47 in the LIR participants , and 1.29 ± 0.55 in the OIR participants . After adjustment for age and sex , the relations of lathosterol-cholesterol ratios were as follows : LIS < OIR ( P < 0.001 ) , LIS < LIR ( P = 0.03 ) , and LIR < OIR ( P = 0.002 ) . Total sterol concentrations were positively associated with S(I ) and negatively associated with obesity , whereas lathosterol correlations were the opposite . CONCLUSIONS Cholesterol absorption was highest in the LIS participants , whereas cholesterol synthesis was highest in the LIR and OIR participants . Therapeutic diets for hyperlipidemia should emphasize low-cholesterol diets in LIS persons and weight loss to improve S(I ) and to decrease cholesterol overproduction in LIR and OIR persons
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 .