desmosterol and Hypercholesterolemia

We hypothesized that (I) certain features in cholesterol metabolism at baseline could predict a response to statins, (II) good and poor responders to statins have a differential profile of serum and fecal sterols and (III) serum non-cholesterol sterols reflect cholesterol metabolism on statins.. We examined serum lipids, serum and fecal cholesterol, cholesterol precursors, cholestanol and phytosterols and cholesterol metabolism among 20 hypercholesterolemic men at baseline and on 16-wk simvastatin/fluvastatin treatment. At baseline, the mean of serum cholestanol/cholesterol was 11% lower but those of lathosterol/cholesterol, lathosterol/cholestanol, desmosterol/cholesterol, desmosterol/cholestanol were 36-65% higher among good than poor responders (p<0.05 for each). On statins, reductions in ratios of serum precursor sterols and increases of absorption sterols were 1.8-2.9 times higher among good than poor responders (p<0.05 for each). In the whole study group, changes from baseline values of lathosterol/cholestanol were related to those of cholesterol and LDL-C in serum (r=+0.513 and +0.451, p=0.021 and 0.046, respectively). Serum lathosterol ratios to cholesterol, cholestanol and sitosterol consistently reflected a ratio of cholesterol synthesis (mg/d/kg)/fractional cholesterol absorption (%) (r-range +0.456 to +0.727, p<0.05 for each).. Low serum baseline ratios to cholesterol of lathosterol, cholestenol and desmosterol, but a high ratio of cholestanol predicted a poor response to statins. Good responders were characterized by more profound reductions of serum and fecal (lathosterol) precursor sterols and increases of serum absorption marker sterol ratios on statins. Serum surrogate sterol markers of cholesterol metabolism were applicable in evaluating cholesterol absorption and synthesis also on statins.

Topics: Cholestanol; Cholesterol; Desmosterol; Double-Blind Method; Fatty Acids, Monounsaturated; Fluvastatin; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypercholesterolemia; Indoles; Lipids; Male; Middle Aged; Simvastatin; Sterols

Genetic loci predict <5% of variation in low-density lipoprotein cholesterol (LDL-C) response to statins. Cholestanol and desmosterol are plasma markers of cholesterol absorption and synthesis, respectively. Because statins lower LDL-C by inhibiting cholesterol synthesis, we studied the relationship between cholestanol and desmosterol and LDL-C response to atorvastatin.. High-risk patients were treated with 80 mg of atorvastatin for 6 weeks. LDL-C response to atorvastatin was related to baseline cholestanol to cholesterol ratio (CCR) and desmosterol. The following comparisons were used: (1) correlates of percentage LDL-C response, (2) baseline characteristics of hyperresponders versus hyporesponders, and (3) binary logistic regression analysis for predictors of achieved LDL-C <70 mg/dL.. One hundred fifty-four patients were enrolled of which 118 completed the study with adequate adherence. Average LDL-C reduction was 57% ± 13% (mean ± SD). On univariate analysis, desmosterol and CCR correlated with percentage LDL-C reduction and multivariate modeling explained approximately 16% of the variation in response. Atorvastatin hyperresponders had higher mean desmosterol (P = 0.046) and lower CCR (P = 0.035) than hyporesponders. On logistic regression analysis for the outcome of achieved LDL-C of <70 mg/dL, baseline LDL-C and CCR were significant predictors; odds ratios were 0.932 and 0.979, respectively.. CCR and desmosterol explain more variation in LDL-C response to statin than that reported with pharmacogenomics. CCR and desmosterol may guide lipid-lowering therapy.

Topics: Absorption; Aged; Atorvastatin; Biomarkers; Cholestanol; Cholesterol; Cholesterol, LDL; Desmosterol; Female; Heptanoic Acids; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypercholesterolemia; Male; Prognosis; Prospective Studies; Pyrroles

Topics: Cholesterol; Cholesterol, LDL; Desmosterol; Humans; Hypercholesterolemia; Hyperlipidemias; Hyperlipoproteinemia Type II; Lipids; Sitosterols; Squalene; Stigmasterol

The dynamics of cholesterol homeostasis and the development of cardiovascular disease (CVD) are complex and multifactorial, to which adds individual variability in the proportion of cholesterol from exogenous versus endogenous sources. The aim of this study was to undertake the first characterization of cholesterol absorption and synthesis profiles in Portuguese hypercholesterolemic adults through the quantification of surrogate markers, and the analysis of the predictive value of age and sex on the cholesterol homeostasis biomarkers.. Serum samples for the measurement of lipid profiles and cholesterol homeostasis markers were obtained for 100 men and 112 women, aged 30-65, with TC ≥ 5.2 mmol/L (~200mg/dL) and/or LDL-C ≥ 2.6 mmol/L (~100mg/dL), none of whom were on any lipid-lowering therapy.. Overall, sex-specific significant differences were observed in the cholesterol homeostasis markers and lipid profiles; women had lower cholesterol synthesis marker concentrations (P<0.01 for lathosterol) and lipid parameters (except for HDL-C concentrations). Age-related significant differences were also found, including higher concentrations of cholesterol absorption markers in association with increasing age.. In our study, the predictors of higher levels of cholesterol absorption markers were higher age and female gender.

Topics: Adult; Age Factors; Aged; Biomarkers; Cholestanol; Cholesterol; Cholesterol, HDL; Cholesterol, LDL; Cross-Sectional Studies; Desmosterol; Diet; Female; Homeostasis; Humans; Hypercholesterolemia; Male; Middle Aged; Phytosterols; Portugal; Sex Factors; Sitosterols; Triglycerides

Plant sterols such as sitosterol and campesterol are frequently applied as functional food in the prevention of atherosclerosis. Recently, it became clear that plasma derived plant sterols accumulate in murine brains. We questioned whether plant sterols in the brain are associated with alterations in brain cholesterol homeostasis and subsequently with brain functions. ATP binding cassette (Abc)g5-/- mice, a phytosterolemia model, were compared to Abcg5+/+ mice for serum and brain plant sterol accumulation and behavioral and cognitive performance. Serum and brain plant sterol concentrations were respectively 35-70-fold and 5-12-fold increased in Abcg5-/- mice (P<0.001). Plant sterol accumulation resulted in decreased levels of desmosterol (P<0.01) and 24(S)-hydroxycholesterol (P<0.01) in the hippocampus, the brain region important for learning and memory functions, and increased lanosterol levels (P<0.01) in the cortex. However, Abcg5-/- and Abcg5+/+ displayed no differences in memory functions or in anxiety and mood related behavior. The swimming speed of the Abcg5-/- mice was slightly higher compared to Abcg5+/+ mice (P<0.001). In conclusion, plant sterols in the brains of Abcg5-/- mice did have consequences for brain cholesterol metabolism, but did not lead to an overt phenotype of memory or anxiety related behavior. Thus, our data provide no contra-indication for nutritional intake of plant sterol enriched nutrition.

Topics: Affect; Animals; Anxiety Disorders; Atherosclerosis; ATP-Binding Cassette Transporters; Behavior, Animal; Brain; Cholesterol; Desmosterol; Diet; Hippocampus; Homeostasis; Hydroxycholesterols; Hypercholesterolemia; Intestinal Diseases; Lanosterol; Lipid Metabolism, Inborn Errors; Male; Maze Learning; Memory; Mice; Mice, Mutant Strains; Phytosterols; Sitosterols; Stigmasterol

A newly developed high-performance liquid chromatography/mass spectrometry (HPLC/MS) method has been successfully used to analyze plasma concentrations of various phytosterols (cholestanol and beta-sitosterol) and cholesterol metabolites (desmosterol and lathosterol). This was based on an unusual solvent combination of water/methanol vs. methanol/acetone/n-hexane applied on a Purospher Star RP-18e (125 x 2 mm, 3 microm) column, which proved excellent for the separation, identification and quantification of plasma sterols. Simple solid-phase extraction preparation of plasma samples was performed, followed by the developed fast and robust HPLC separation. Results on four groups of people were compared, those with low, normal and high plasma cholesterol levels and those with high cholesterol levels on statin therapy, and the results were evaluated using linear discriminant analysis (LDA). Variable selection for LDA was achieved using backward removal selection. Highly discriminatory variables were the ratios of desmosterol to sitosterol and of lathosterol to total plasma cholesterol. The latter ratio was also excellent for distinguishing subjects on statin therapy. The success rate of classification was 100%. The present pilot study shows the potential of HPLC/MS analysis and chemometrics for studying cholesterol-related disorders and warrants future full-scale medical study.

Topics: Cholestanol; Cholesterol; Chromatography, High Pressure Liquid; Desmosterol; Discriminant Analysis; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypercholesterolemia; Mass Spectrometry; Pilot Projects; Sitosterols; Sterols

We measured serum cholesterol concentrations and synthesis markers (e.g. serum lathosterol to cholesterol ratio), and absorption markers (e.g. serum campesterol to cholesterol ratio) of cholesterol in 319 good responders (GR; dose 20 mg up to 1 year) and in 115 poor responders (PR; dose increased at 6 weeks to 40 mg) among Finnish participants in the Scandinavian Simvastatin Survival Study at baseline, 6 weeks and 1 year of the simvastatin treatment. The baseline cholesterol level and the ratios of the absorption markers were higher and those of the synthesis markers lower in PR than GR. The ratios of the precursor sterols were negatively related to the baseline cholesterol in GR only (P=0.003). The cholesterol levels, and the ratios of the precursor sterols were decreased and those of the absorption marker sterols increased less consistently in PR than GR by 20 mg, the group differences being only slightly lessened by the dose addition to 40 mg. One-year differences were still frequently significant. The baseline cholesterol concentrations were negatively related to the reduction of the precursor sterol ratios in GR, the change of cholesterol being positively related to those of the synthesis markers and negatively to those of the absorption markers only in PR. Thus, patients needing large statin dose for cholesterol normalization have high absorption and low synthesis of cholesterol, yet baseline synthesis is inversely related to cholesterol level only in GR. The synthesis rate is less markedly reduced by the large than by the small statin dose in the PR, and the reduction is related, in contrast to that in the GR, to lowering of cholesterol.

Topics: Cholestanol; Cholesterol; Desmosterol; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypercholesterolemia; Simvastatin; Sitosterols

The hypocholesterolaemic mechanism of activated charcoal was studied in seven patients with primary hypercholesterolaemia. The reduction of serum cholesterol was correlated with the serum concentrations of cholesterol precursors and of two plant sterols. Activated charcoal, 8 g t.i.d. for 4 weeks, reduced serum concentration of total cholesterol by 27% (P less than 0.01). The effect was accompanied by a moderate elevation (P less than 0.05) in serum squalene and desmosterol concentrations and by a marked increase (up to 300-700%) in serum lathosterol and delta 8 lathosterol concentrations. The levels of two plant sterols, campesterol and beta-sitosterol, were unchanged or only slightly decreased by the use of activated charcoal. The decrease of serum cholesterol concentration had significant negative correlations with serum lathosterol and delta 8 lathosterol, and significant positive correlations with serum cholestanol and beta-sitosterol. These observations suggest an increased cholesterol synthesis upon treatment with activated charcoal, probably caused by the interference with the enterohepatic circulation of bile acids.

Topics: Anticholesteremic Agents; Charcoal; Cholesterol; Desmosterol; Female; Humans; Hypercholesterolemia; Male; Middle Aged; Phytosterols; Sitosterols

To test the hypothesis that high-responding rhesus monkeys should have a greater degree of feedback inhibition of hepatic cholesterol biosynthesis than the low-responding monkeys because the former group absorbs a higher percentage of cholesterol than the later group, we determined the relative rates of cholesterol biosynthesis by measuring plasma desmosterol levels while feeding triparanol along with diets high and low in cholesterol and with or without 2% plant sterols. The build-up of plasma desmosterol was more rapid in low-responders than in high-responders on all diets; the difference was significant only on diets low in plant sterols. In both groups, adding plant sterols to either diet increased the initial slope of plasma desmosterol build-up (significant only for high cholesterol diet). The mean percent cholesterol absorption in high-responders was significantly higher than in low-responders on high and low cholesterol diets with low levels of plant sterols. On adding 2% plant sterols to both diets, the percent cholesterol absorption decreased significantly and became essentially the same in both groups. Triparanol feeding decreased plasma cholesterol significantly in both groups on both diets; the decrease in the low-responders was smaller than in high-responders. Addition of plant sterols to either diet also reduced plasma cholesterol in both groups, but the decrease was significant only in the high-responders on high cholesterol diet. The study demonstrates that high-responders have a greater degree of feedback inhibition of cholesterol biosynthesis than low-responders probably because of higher absorption of cholesterol. The results also indicate that both endogenous and exogenous cholesterol are effective mediators of the feedback inhibition mechanism.

Topics: Animals; Cholesterol; Cholesterol, Dietary; Desmosterol; Feedback; Hypercholesterolemia; Intestinal Absorption; Macaca mulatta; Male; Phytosterols; Triparanol

Direct gas liquid chromatography (GLC) of total plasma lipids showed small peaks (0.5-1.5% of total free sterol area) corresponding to free C28 and C29 sterols in ca. 50% of some 3,000 normal subjects and patients with hyperlipemia. Comparable proportions of similar peaks were present in the sterol fraction isolated from the red blood cells of many of these subjects. The maximum levels of these components in the plasma and red blood cells of domestic and laboratory animals were up to 10 times higher than those seen in man. Detailed gas chromatography/mass spectrometry analyses of the plasma lipids from a much more limited number of subjects and animals showed that the GLC peaks corresponding to the free C28 and C29 sterols were largely due to the plant sterols campesterol, stigmasterol, and beta-sitosterol. In all instances, variable amounts (0.05-0.2% of the total free sterol area) of 7-dehydrocholesterol, desmosterol, lanosterol, and cholesterol alpha-oxide were also detected. While the total content and composition of the plasma plant sterols appeared to vary greatly among the subjects, it never exceeded 2% of total sterol in the normal subjects and patients examined. There was no evidence for a significant increase in the plant sterol content of the plasma of patients with hypercholesterolemia or hypertriglyceridemia.

Topics: Animals; Cholesterol; Chromatography, Gas; Desmosterol; Erythrocytes; Gas Chromatography-Mass Spectrometry; Humans; Hypercholesterolemia; Hyperlipidemias; Phytosterols; Sitosterols; Species Specificity

Topics: Animals; Anticholesteremic Agents; Body Weight; Cholesterol; Desmosterol; Estrone; Hypercholesterolemia; Liver; Male; Organ Size; Rats; Triparanol