Lathosterol Levels Research Articles

Lathosterolosis, a Novel Multiple-Malformation/Mental Retardation Syndrome Due to Deficiency of 3β-Hydroxysteroid-Δ 5-Desaturase

We report the clinical, biochemical, and molecular characterization of a patient with a novel defect of cholesterol biosynthesis. This patient presented with a complex phenotype, including multiple congenital anomalies, mental retardation, and liver disease. In the patient's plasma and cells, we found increased levels of lathosterol. The biosynthesis of cholesterol in the patient's fibroblasts was defective, showing a block in the conversion of lathosterol into 7-dehydrocholesterol. The activity of 3beta-hydroxysteroid-Delta(5)-desaturase (SC5D), the enzyme involved in this reaction, was deficient in the patient's fibroblasts. Sequence analysis of the SC5D gene in the patient's DNA, showing the presence of two missense mutations (R29Q and G211D), confirmed that the patient is affected by a novel defect of cholesterol biosynthesis.

Cholesterol metabolism in primary biliary cirrhosis during simvastatin and UDCA administration

Little is known about the effects of cholesterol-lowering agents in hypercholesterolemic patients with primary biliary cirrhosis (PBC). The aim of this study was to compare the changes induced by simvastatin and ursodeoxycholic acid (UDCA) on cholesterol metabolism in patients with PBC and preserved liver function. Six patients with PBC were administered simvastatin (40 mg/day) for 30 days and, after a washout period of 30 days, ursodeoxycholic acid (600 mg/day) for 30 days. Serum levels of lathosterol, campesterol, 7α-hydroxycholesterol, and 27-hydroxycholesterol were measured by gas chromatography-mass spectrometry. During simvastatin administration, reduction of cholesterol levels (34% in 30 days) was paralleled by the decrease of lathosterol (55%), whereas concentrations of campesterol and of the two hydroxysterols were not substantially modified. During ursodeoxycholic acid administration, a trend toward a decrease of serum cholesterol concentrations was observed after only one year of treatment, and these changes were paralleled by the decrease of campesterol serum levels. Both simvastatin and UDCA were well tolerated, and a reduction of serum liver enzyme levels occurred with the latter. Simvastatin proved to be safe and effective in reducing serum cholesterol levels in patients with PBC by an inhibitory effect on cholesterol synthesis occurring within 24 h. —Del Puppo, M., M. Galli Kienle, A. Crosignani, M. L. Petroni, B. Amati, M. Zuin, and M. Podda. Cholesterol metabolism in primary biliary cirrhosis during simvastatin and UDCA administration.

Divergent changes in serum sterols during a strict uncooked vegan diet in patients with rheumatoid arthritis

The effects of a strict uncooked vegan diet on serum lipid and sterol concentrations were studied in patients with rheumatoid arthritis. The subjects were randomized into a vegan diet group (n 16), who consumed a vegan diet for 2-3 months, or into a control group (n 13), who continued their usual omnivorous diets. Serum total and LDL-cholesterol and -phospholipid concentrations were significantly decreased by the vegan diet. The levels of serum cholestanol and lathosterol also decreased, but serum cholestanol:total cholesterol and lathosterol:total cholesterol did not change. The effect of a vegan diet on serum plant sterols was divergent as the concentration of campesterol decreased while that of sitosterol increased. This effect resulted in a significantly greater sitosterol:campesterol value in the vegan diet group than in the control group (1.48 (SD 0.39) v. 0.72 (SD 0.14); P < 0.001). A higher concentration of campesterol compared with sitosterol is normal in omnivorous subjects and can be explained by lower absorption and esterification rates of sitosterol. Our results suggest that a strict uncooked vegan diet changes the relative absorption rates of these sterols and/or their biliary clearance.

Effect of simvastatin in addition to chenodeoxycholic acid in patients with cerebrotendinous xanthomatosis

The effects of combination therapy with chenodeoxycholic acid (CDCA) and simvastatin on serum cholestanol, low-density lipoprotein (LDL) cholesterol, and lathosterol levels were investigated in seven adult patients with cerebrotendinous xanthomatosis (CTX) who were on long-term treatment with CDCA. The patients were treated with a combination of CDCA 750 mg daily and an increasing dose of simvastatin from 10 mg to 40 mg daily for a period of 6 months. We found a significant effect of this combination therapy compared with CDCA alone in terms of decreasing the serum cholestanol and LDL cholesterol levels, particularly with a daily dose of 40 mg simvastatin. The mean cholestanol level decreased from 9.27 micromol/L (baseline) to 6.69 micromol/L (40 mg simvastatin), while the mean LDL cholesterol level decreased from 5.08 mmol/L (baseline) to 3.04 mmol/L (40 mg simvastatin). No side effects were reported, and there were no effects on the clinical condition, cerebral magnetic resonance imaging (MRI), visual evoked potentials, and electroencephalographic features. We conclude that a combination of 750 mg CDCA and 40 mg simvastatin daily is effective to further reduce serum cholestanol, LDL cholesterol, and lathosterol in adult CTX patients treated with long-term CDCA. Whether this combination treatment will be effective for the long-term prevention of neurological deterioration and atherosclerosis remains to be established.

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.

Effects of dietary coconut oil, butter and safflower oil on plasma lipids, lipoproteins and lathosterol levels.

The aim of this present study was to determine plasma levels of lathosterol, lipids, lipoproteins and apolipoproteins during diets rich in butter, coconut fat and safflower oil. The study consisted of sequential six week periods of diets rich in butter, coconut fat then safflower oil and measurements were made at baseline and at week 4 in each diet period. Forty-one healthy Pacific island polynesians living in New Zealand participated in the trial. Subjects were supplied with some foods rich in the test fats and were given detailed dietary advice which was reinforced regularly. Plasma lathosterol concentration (P < 0.001), the ratio plasma lathosterol/cholesterol (P=0.04), low density lipoprotein (LDL) cholesterol (P<0.001) and apoB (P<0.001) levels were significantly different among the diets and were significantly lower during coconut and safflower oil diets compared with butter diets. Plasma total cholesterol, HDL cholesterol and apoA-levels were also significantly (P< or =0.001) different among the diets and were not significantly different between buffer and coconut diets. These data suggest that cholesterol synthesis is lower during diets rich in coconut fat and safflower oil compared with diets rich in butter and might be associated with lower production rates of apoB-containing lipoproteins.

HMG-CoA reductase is not the site of the primary defect in phytosterolemia

Phytosterolemia is an autosomal recessive disorder characterized by the excessive absorption, reduced excretion, and consequent high tissue and plasma levels of plant sterols, by the presence of tendon xanthomas, and by premature atherosclerosis. Low HMG-CoA reductase (HRase) activity and mass have been reported in liver and mononuclear leucocytes and low mRNA levels in liver from phytosterolemic subjects. These results led to the proposal that the primary defect in this condition involves the HRase gene locus. We examined this hypothesis in phytosterolemic subjects and heterozygous parents from four unrelated families. A variable number tandem repeat (VNTR) polymorphism of the HRase gene in the three informative families and a ScrFI restriction fragment length polymorphism (RFLP) within intron 2 of the gene in one of these families, segregated independently of the disease phenotype. Biological parentage was confirmed in the family in whom both polymorphisms failed to segregate with the disorder. These results conclusively exclude the HRase gene locus as the site of the primary defect in phytosterolemia. The study was extended by examining plasma levels of mevalonic acid and lathosterol, both markers of cholesterol biosynthesis, in response to cholestyramine, a bile acid sequestrant that is known to up-regulate HRase. Oral administration of cholestyramine resulted in a substantial (7.7-fold) increase in mevaIonic acid levels in two phytosterolemic subjects, compared with a 2.2-fold rise in their obligate heterozygote parents and a 2.3-fold increase in three healthy control subjects. The lathosterol/cholesterol (L/C) ratio showed a quantitatively similar response. Baseline levels of mevalonate and the L/C ratio were low in the phytosterolemic patients in conformity with reports of reduced cholesterol biosynthesis and HRase activity in this disorder. These functional data provide support for the concept that the primary defect in phytosterolemia does not affect a trans gene locus responsible for the constitutive expression or regulation of HMG-CoA reductase.

Circulating markers for biosynthesis of cholesterol and bile acids are not depressed in asymptomatic gallstone subjects

Background/Aims: Cholesterol gallstone disease is often associated with an increased biliary secretion rate of cholesterol, which may be due to abnormalities in hepatic cholesterol metabolism. The aim of the present study was to investigate whether gallstone subjects may have an underlying defect in hepatic cholesterol and bile acid formation.Methods: In 41 asymptomatic gallstone subjects, randomly selected from a population of both sexes 40 and 60 years of age, and in 72 age- and sex-matched controls, plasma levels of lathosterol (reflecting hepatic HMG CoA reductase activity) and 7α-hydroxy-4-cholesten-3-one (reflecting cholesterol 7α-hydoxylase activity) were analysed. In a subgroup of gallstone subjects and controls, plasma levels of 27-hydroxy cholesterol were also determined.Results: The gallstone subjects had normal plasma levels of cholesterol but displayed 20–25% higher plasma levels of triglycerides compared with the controls. The plasma level of lathosterol was not significantly different between the two groups of subjects whereas the plasma level of 7α-hydroxy-4-cholesten-3-one was about 40% higher in the gallstone subjects compared with the controls. Positive correlations were obtained between plasma levels of 7α-hydroxy-4-cholesten-3-one and triglycerides in both groups of subjects. The plasma level of 27-hydroxy cholesterol was similar in gallstone subjects and controls.Conclusions: The previously reported hypersecretion of cholesterol in gallstone patients is not due to a single metabolic defect leading to increased hepatic synthesis of cholesterol or decreased catabolism of cholesterol to bile acids via 7α-hydroxylation or 27-hydroxylation of cholesterol.

The effect of vitamin C in high doses on plasma and biliary lipid composition in patients with cholesterol gallstones: prolongation of the nucleation time.

Vitamin C deficiency in guinea pigs leads to cholesterol supersaturation of bile and formation of cholesterol gallstones. It has been suggested that there may also exist an association between vitamin C and cholesterol gallstones in man, but such a relationship has not been studied in gallstone patients. In order to study the possible effects of vitamin C on gallstone disease in humans, plasma lipid levels, hepatic cholesterol metabolism, biliary lipid composition, cholesterol saturation and nucleation time of gallbladder bile were analysed in 16 consecutive gallstone patients, who were planned for laparoscopic cholecystectomy and were treated with vitamin C (500 mg, four times a day) for 2 weeks before surgery. The plasma concentration of vitamin C increased by 42% in the treatment group. The concentrations of plasma lipids did not differ before and after vitamin C treatment; nor did the plasma levels of lathosterol and 7 alpha-hydroxy-4-cholesten-3-one, reflecting cholesterol and bile acid synthesis respectively. The relative concentrations of cholesterol, bile acids and cholesterol concentration of bile did not differ significantly between the two groups, but the relative concentration of phospholipids was slightly higher in the treated group. The bile acid composition was changed; the percentage of cholic acid being lower and those of deoxycholic acid, ursodeoxycholic acid and lithocholic acid higher in the vitamin C-treated patients compared with the untreated group. The nucleation time was significantly longer in the treatment group (7 days) compared with the untreated group (2 days). Our findings indicate that vitamin C supplementation may also influence the conditions for cholesterol gallstone formation in humans.

The effects of ursodeoxycholic acid on serum and biliary noncholesterol sterols in patients with gallstones.

Litholytic bile acid ursodeoxycholic acid (UDCA) reduces biliary cholesterol secretion and alters cholesterol metabolism by mechanisms that are not fully understood. To evaluate cholesterol metabolism during UDCA treatment, we studied serum and biliary lipids and cholesterol precursor sterols (lanosterol and other dimethyl and monomethyl sterols, lathosterols, and desmosterol), indicators of cholesterol synthesis, and plant sterols campesterol and sitosterol, indicators of cholesterol absorption, before and during administration of UDCA, 9 mg/kg/d, for 26 weeks in eight patients with radiolucent gallstones. During UDCA administration, serum lipid concentrations were unchanged, but the biliary concentration and molar percentage of cholesterol were markedly decreased. The proportions of the cholesterol precursor sterols to cholesterol were significantly interrelated between serum and bile before and especially during UDCA administration. Lanosterol and lathosterol levels, especially in bile, were significantly decreased by 43% and 34%, suggesting that UDCA may inhibit cholesterol synthesis. Levels of the other methylated precursor sterols were increased in serum and bile. The esterification percentages of all sterols were unchanged. The plant sterol-to-cholesterol ratios increased significantly in serum and bile, and there was an inverse correlation between the increment of serum plant sterols and decreased biliary molar percentage of cholesterol. In conclusion, UDCA may inhibit cholesterol synthesis possibly at the squalene synthase or 4alpha-demethylase steps, resulting in decreased biliary secretion of cholesterol. Reduced biliary sterol secretion probably increased serum plant sterol levels, indicating that under these conditions they no longer reflect the intestinal efficiency of cholesterol absorption.

Changes in biliary lipid output after interruption of pravastatin treatment in humans

The use of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (e.g. pravastatin) has gradually increased in the treatment of hypercholesterolaemia. By inhibiting HMG-CoA reductase (the rate-limiting enzyme in cholesterol synthesis) activity, cholesterol synthesis in the liver is reduced and the plasma level of cholesterol, especially low-density lipoprotein (LDL)-cholesterol, is substantially lowered. Simultaneously, inhibition of HMG CoA reductase activity is associated with increased synthesis and accumulation of larger amounts of HMG CoA reductase enzyme protein. The main purpose of this study was to determine if the cessation of pravastatin treatment causes a rapid increase in the synthesis and biliary secretion of cholesterol, a condition which might lead to a temporarily increased cholesterol saturation of bile. Nine patients undergoing surgery for stones in the common bile duct were fitted with T-tubes in the common bile duct peroperatively; the side arm of the T-tube was left open postoperatively, creating a biliary fistula. All patients were given 6 days' treatment with pravastatin (20 mg b.i.d.) following the operation. Bile was collected from the T-tube, in 12-h fractions during this period and for another 3 days after termination of the treatment. Plasma levels of lipoproteins and lathosterol--reflecting cholesterol synthesis--were determined on several occasions. After cessation of pravastatin treatment, the plasma levels of total cholesterol and LDL-cholesterol increased by 21% and 33% respectively. High-density lipoprotein (HDL)-cholesterol did not change. The plasma level of lathosterol was increased two- to fourfold. Outputs of bile acids and phospholipids were significantly increased (23% and 10% respectively) after termination of treatment, whereas the output of cholesterol was not significantly changed. Cholesterol saturation was reduced by 20%, from 175 +/- 37% to 140 +/- 19%, but this change was not significant. The results indicate that, with the present experimental model (biliary diversion), the synthesis and biliary secretion of bile acids seem to be largely dependent on the de novo synthesis of cholesterol in the liver, whereas the biliary output of cholesterol is not.

Plasma Lathosterol as a Screening Test for Bile Acid Malabsorption Due to Ileal Resection: Correlation with 75SeHCAT Test and Faecal Bile Acid Excretion

1. Plasma lathosterol concentration, known to reflect cholesterol and bile acid synthesis, was evaluated as a screening test for bile acid malabsorption, comparing it with faecal bile acid measurements, SeHCAT test and Schilling test in 22 subjects of whom six were healthy controls and 16 had Crohn's disease with ileal resections of varying length. 2. Plasma lathosterols and other non-cholesterol sterols were determined by GLC. Faecal bile acids were measured by GLC, and SeHCAT retention times by gamma camera. The study subjects were divided into two groups according to the degree of bile acid malabsorption: controls (faecal bile acids < 10 mg day-1 kg-1, n = 9) and bile acid malabsorption (faecal bile acids > 10 mg day-1 kg-1, n = 13). 3. Faecal bile acid excretion was 5.9 +/- 1.0 mg day-1 kg-1 in control subjects and 45.7 +/- 6.1 mg day-1 kg-1 in the bile acid malabsorption group. The biological half-life of 75SeHCAT (T1/2) was 95.6 +/- 16.3 h and 14.1 +/- 4.1 h, respectively. Plasma lathosterol levels were significantly elevated in patients with bile acid malabsorption (742 +/- 84 micrograms/ml compared with 400 +/- 59 micrograms/ml in control subjects) and correlated closely with faecal bile acid levels (r = 0.779, P < 0.001), with 75SeHCAT T1/2 (r = -0.524, P < 0.05) and with Schilling test (r = -0.591, P < 0.05). Significant correlations were also obtained for delta 8-cholestenol with faecal bile acids (r = 0.784, P < 0.001) and 75SeHCAT (r = -0.505, P < 0.05). The biological half-life of SeHCAT correlated with faecal bile acid excretion (r = -0.702, P < 0.001). Using mean+2 SD of lathosterol (In micrograms/ml cholesterol) as a cut-off value and 10 mg day-1 kg-1 as the upper limit for faecal bile acid excretion, the test gives 100% sensitivity and 82% specificity for plasma lathosterol determination to detect bile acid malabsorption. 4. The results indicate that both the 75SeHCAT test and plasma lathosterol detect bile acid malabsorption in patients with ileal resections for Crohn's disease. However, plasma lathosterol is a simpler and less expensive method.

Decreased plasma lathosterol levels in growth hormone deficient men during treatment with growth hormone

Decreased plasma lathosterol levels in growth hormone deficient men during treatment with growth hormone

Serum lathosterol levels in human subjects reflect changes in whole body cholesterol synthesis induced by lovastatin but not dietary cholesterol.

We measured serum lathosterol levels and whole body cholesterol synthesis by sterol balance in 12 human subjects on a metabolic ward in four randomly allocated, 6-7 week periods: 1) lovastatin (40 mg b.i.d.) + low cholesterol diet (mean 246 mg/day); 2) lovastatin + high cholesterol diet (mean 1071 mg/day); 3) low cholesterol diet alone; and 4) high cholesterol diet alone. Whole body cholesterol synthesis was significantly reduced both by lovastatin (P = 0.0004) and by high dietary cholesterol (P = 0.0005). Serum total lathosterol (micrograms/dl) was reduced by lovastatin (P < 0.0001), but was not significantly altered (and actually tended to increase) during consumption of the high cholesterol diet, presumably because eggs contained appreciable lathosterol as demonstrated by direct analysis. Results were similar for total versus free lathosterol and for lathosterol expressed as micrograms/dl serum versus micrograms/100 mg cholesterol. We conclude that serum lathosterol does not reflect changes in cholesterol synthesis induced by dietary cholesterol. Studies using serum lathosterol as an indicator of cholesterol synthesis must be carefully controlled for dietary cholesterol.

Evidence for a short-term stimulatory effect of insulin on cholesterol synthesis in newly insulin-treated diabetic patients

To gain further insight into the effects of insulin on cholesterol synthesis in humans, 19 newly insulin-treated diabetic patients were studied before any insulin treatment (study day 1) and after a few days of optimized glycemic control with a continuous intravenous insulin infusion (study day 2). The patients were divided into two groups according to their clinical characteristics and laboratory disorders. Groups I and II consisted, respectively, of 10 newly diagnosed type I diabetic patients and nine type II diabetic patients with secondary failure to oral antidiabetic drugs. Cholesterol synthesis was estimated from the determination of serum lathosterol, a metabolic precursor in the cholesterol pathway, and from the serum lathosterol to cholesterol ratio. Serum cholesterol (millimolar, mean ± SEM) remained unchanged in both groups. After insulin therapy (study day 2), serum lathosterol (micromolar) and the serum lathosterol to cholesterol ratio (molar ratio × 10 3) were significantly increased as compared with baseline (study day 1). Serum lathosterol levels were as follows: 9.9 ± 2.0 versus 4.1 ± 0.4 ( P < .02) in group I, and 9.9 ± 0.8 versus 5.7 ± 0.7 ( P < .005) in group II; serum lathosterol to cholesterol ratios were 2.10 ± 0.39 versus 0.86 ± 0.11 ( P < .005) in group I, and 1.92 ± 0.12 versus 0.98 ± 0.10 ( P < .001) in group II. The data indicate that in newly insulin-treated diabetic patients, short-term intensive insulin therapy has a stimulatory effect on cholesterol synthesis and even results in cholesterol overproduction.

Effects of pravastatin and cholestyramine on products of the mevalonate pathway in familial hypercholesterolemia.

Patients with heterozygous familial hypercholesterolemia (n = 12) were treated either with pravastatin, a specific inhibitor of HMG-CoA reductase, or cholestyramine, followed by a period of combined treatment with both drugs. Initially, these patients had increased serum levels of low density lipoprotein (LDL) cholesterol (8.77 +/- 0.48 mmol/l; SEM), lathosterol (5.32 +/- 0.60 mg/l), and ubiquinone (0.76 +/- 0.09 mg/l), while the serum dolichol concentration was in the normal range. Cholestyramine treatment (n = 6) decreased the levels of LDL cholesterol (-32%) and increased lathosterol (+125%), but did not change dolichol or ubiquinone levels in a significant manner. Pravastatin treatment (n = 6) decreased LDL cholesterol (-27%), lathosterol (-46%), and ubiquinone (-29%). In this case, the amount of dolichol in serum also showed a small but statistically insignificant decrease (-16%) after 12 weeks of treatment. Combined treatment with cholestyramine and pravastatin (n = 6) resulted in changes that were similar to, but less pronounced than, those observed during pravastatin treatment alone. In no case was the ratio between ubiquinone and LDL cholesterol reduced. Possible effects on hepatic cholesterol, ubiquinone, and dolichol concentrations were studied in untreated (n = 2), cholestyramine-treated (n = 2), and pravastatin-treated (n = 4) gallstone patients and no consistent changes could be observed. The results indicate that treatment with pravastatin in familial hypercholesterolemia decreases serum ubiquinone levels in proportion to the reduction in LDL cholesterol.

Plasma levels of lathosterol and phytosterols in relation to age, sex, anthropometric parameters, plasma lipids, and apolipoprotein E phenotype, in 160 Dutch families

In this study, the relation of plasma levels of lathosterol (an indicator of whole body cholesterol synthesis) and plant sterols (indicator of cholesterol absorption) with age, sex, weight, height, plasma lipids, and lipoproteins, and with apolipoprotein (apo) E phenotype, was investigated in a group of 160 nuclear families consisting of twins living with their parents. Lathosterol was higher in fathers than in mothers, but not different between boys and girls. In each of these four groups, there was a strong correlation with plasma and low-density lipoprotein (LDL)-cholesterol and -triglyceride, as well as with body weight, but not with height or high-density lipoprotein (HDL)-cholesterol. In adults, lathosterol was inversely correlated with plant sterols. Lathosterol was higher in children with E4 3 phenotype than in those with E3 3 or E3 2 ; in adults, lathosterol did not differ among the various E phenotypes. The plasma levels of the two plant sterols, campesterol and β-sitosterol, were highly correlated with each other, and also with plasma or LDL-cholesterol, in each of the four groups. Plant sterols were higher in adults or children with E4 3 phenotype as compared with those with other phenotypes. In multivariate analysis (performed separately for two groups of adults and children) plasma cholesterol, plasma plant sterols, plasma triglycerides, and weight were found to make significant contributions to the variation of lathosterol in all groups, and E phenotype and sex only in one group, while age did not contribute in any group. For plant sterols, plasma cholesterol and lathosterol were significant independent predictors in all groups, sex and E phenotype only in one or two of the four groups, and age, weight, height, and HDL-cholesterol in none of the groups. Thus, although lathosterol and plant sterols were weakly related to E phenotype in some of the groups, these findings do not support a major role for the E phenotype in determining rates of cholesterol synthesis or absorption, as claimed by others.

High cholestanol and low campesterol-to-sitosterol ratio in serum of patients with primary biliary cirrhosis before liver transplantation

Serum levels of cholesterol precursors (squalene, delta 8-cholestanol, desmosterol and lathosterol), plant sterols (campesterol and sitosterol), cholestanol and cholestanol/noncholesterol sterol ratios were related to liver damage and liver transplantation indications in healthy controls (n = 26) and in 31 patients with primary biliary cirrhosis divided into group I (S-bilirubin less than 21 mumol/L; n = 14), group II (S-bilirubin 21 to 108 mumol/L; n = 7) and group III (elected for liver transplantation; S-bilirubin 109 to 520 mumol/L; n = 10). The mean serum respective lathosterol levels in controls and in group I were three and two times higher than those in groups II and III, respectively. The plant sterol contents were higher in group II than in groups I and III and the campesterol/sitosterol ratios were lowest in group III. The serum cholestanol levels were high even in group I (i.e., in patients without icterus) and increased progressively to group III, up to 6 and 13 times those in group I and the control group, respectively. The cholestanol/noncholesterol sterol ratios increased progressively from the controls to groups I, II and III. The serum cholestanol levels were positively related to serum bilirubin levels in all primary biliary cirrhosis patients (n = 31, r = 0.906) and to the plant sterol levels in the control group and group I, but significantly negatively in group III. The cholestanol vs. precursor sterol correlations were negative in most cases.(ABSTRACT TRUNCATED AT 250 WORDS)

High cholestanol and low campesterol-to-sitosterol ratio in serum of patients with primary biliary cirrhosis before liver transplantation

Serum levels of cholesterol precursors (squalene, Δ8-cholestenol, desmosterol and lathosterol), plant sterols (campesterol and sitosterol), cholestanol and cholestanol/noncholesterol sterol ratios were related to liver damage and liver transplantation indications in healthy controls (n = 26) and in 31 patients with primary biliary cirrhosis divided into group I (S-bilirubin < 21 μmol/L; n = 14), group II (S-bilirubin 21 to 108 μmol/L; n = 7) and group III (elected for liver transplantation; S-bilirubin 109 to 520 μmol/L; n = 10). The mean sérum respective lathosterol levels in controls and in group I were three and two times higher than those in groups II and III, respectively. The plant sterol contents were higher in group II than in groups I and III and the campesterol/sitosterol ratios were lowest in group III. The serum cholestanol levels were high even in group I (i.e., in patients without icterus) and increased progressively to group III, up to 6 and 13 times those in group I and the control group, respectively. The cholestanol/noncholesterol sterol ratios increased progressively from the controls to groups I, II and III. The serum cholestanol levels were positively related to serum bilirubin levels in all primary biliary cirrhosis patients (n = 31, r = 0.906) and to the plant sterol levels in the control group and group I, but significantly negatively in group III. The cholestanol vs. precursor sterol correlations were negative in most cases. In conclusion, our findings suggest that determination of serum cholestanol and lathosterol levels and cholestanol/plant sterol, campesterol/sitosterol and campesterol/lathosterol ratios might aid staging of liver damage in primary biliary cirrhosis. The high serum cholestanol level associated with the low campesterol/sitosterol ratio could be a significant indicator of end-stage primary biliary cirrhosis and, finally, of the need for liver transplantation. (HEPATOLOGY 1991;13:663–669.)

Hepatic metabolism of cholesterol in Crohn's disease: Effect of partial resection of ileum

To study cholesterol metabolism in Crohn's disease and especially the effect of ileum resection, liver biopsy specimens were obtained from patients undergoing partial ileal resection because of Crohn's disease (n = 17) and patients with Crohn's colitis undergoing colectomy (n = 3). Gallstone-free patients (n = 16) undergoing cholecystectomy because of adenomyomas or polyps of the gallbladder served as controls. The mean levels of cholesterol 7α-hydroxylase activity and 3-hydroxy-3-methylglutaryl coenzyme A reductase activity, rate-determining enzymes in bile acid, and cholesterol synthesis, respectively, were twofold to threefold higher in the ileum-resected patients than in the controls. Significant positive correlations were obtained between length of resected ileum and cholesterol 7α-hydroxylase activity. Provided patients who had received total parenteral nutrition preoperatively were excluded from analysis, a significant correlation was also observed between length of resected ileum and 3-hydroxy-3-methylglutaryl coenzyme A reductase activity. Significant positive correlations were also obtained between length of resected ileum and serum levels of 7α-hydroxycholesterol (a marker for bile acid biosynthesis) and lathosterol (a marker for cholesterol synthesis). The plasma levels of total and low-density lipoprotein cholesterol were negatively correlated to the length of resected ileum. The expression of hepatic low-density lipoprotein-receptor binding activity was determined in five of the patients and in three of the controls. A significant positive correlation was observed between 3-hydroxy-3-methylglutaryl coenzyme A reductase activity and low-density lipoprotein-receptor binding activity. The results show that malabsorption of bile acids leads to parallel stimulation of cholesterol synthesis, cholesterol degradation, and low-density lipoprotein-receptor expression in human liver. The resulting effect in the present patients was a significant reduction in low-density lipoprotein cholesterol.