Applicability of non-cholesterol sterols in predicting response in cholesterol metabolism to simvastatin and fluvastatin treatment among hypercholesterolemic men.

BACKGROUND AND AIMS: 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. METHODS AND RESULTS: 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). CONCLUSIONS: 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.

Cholesterol, non-cholesterol sterols and bile acids in paediatric gallstones.

BACKGROUND: Depending on underlying aetiopathogenetic factors human gallstones contain various amounts of cholesterol, non-cholesterol sterols and bile acids, which have remained unexplored in paediatric gallstone patients. AIMS: To evaluate sterol and bile acids compositions of paediatric gallstones. PATIENTS AND METHODS: Study group included 21 consecutively cholecystectomised children. Gas-liquid chromatography was used to quantitate gallstone sterols and bile acids. Results were compared to adult gallstones (n=194). RESULTS: Cholesterol stones (n=9) had higher proportions of cholesterol and lathosterol, but lower those of lanosterol and phytosterols than pigment stones (n=12) (p<0.05 for each). Patients with gallstone cholesterol content over 70% were female. Gallstone cholesterol positively reflected body mass index and, in cholesterol stones-group, age (r=approximately +0.700, p<0.05). Three patients on parenteral nutrition had brown pigment stones consisting of high amounts of campesterol and sitosterol ranging 483-9303 microg/100 mg of stone. Pigment stones had 13-fold higher amount of bile acids than cholesterol stones (p<0.05). Black pigment stones contained approximately 3-fold higher phytosterol proportions, and pigment stones and cholesterol stones had approximately 43% lower proportions of deoxycholic acid than adults (p<0.05). CONCLUSION: Gallstones in patients on parenteral nutrition are rich in phytosterols. With respect to gallstone sterols, gallstone disease of adolescent girls resembles that of adults. Composition of bile acids in paediatric gallstones is different from adults.

Statin treatment increases the sialic acid content of LDL in hypercholesterolemic patients.

Low density lipoprotein (LDL) with low sialic acid content has been reported to cause intracellular cholesterol accumulation, and therefore desialylation has been proposed to be an atherogenic modification of LDL. However, it is not known whether hypolipidemic treatment has any effect on LDL sialylation. Accordingly, we investigated the sialic acid/apolipoprotein (apo) B ratio of total LDL and its subfractions in 26 moderately hypercholesterolemic patients at baseline and after treatment with statins for 2-3 months. Cholesterol and triglyceride levels were reduced in all apo B-containing lipoproteins, including all LDL subfractions, while the sialic acid ratio was increased in total LDL and in all its subfractions. Cholesterol concentrations and sialic acid ratios were inversely correlated in light and dense LDL subfractions both before and during statin treatment, and the greater the decrease in cholesterol and apo B contents of dense LDL, the higher was the increase in its sialic acid ratio. Furthermore, the lower the baseline sialic acid ratio of dense LDL, the greater was the reduction in its lipid and apo B concentrations. In conclusion, inhibition of cholesterol synthesis by statin treatment increased sialic acid/apo B ratio in LDL proportionately to the decrease of LDL apo B and cholesterol.

Sialic acid content of LDL and lipoprotein metabolism in combined hyperlipidemia and primary moderate hypercholesterolemia.

Low density lipoprotein (LDL) with low sialic acid content has been shown to cause intracellular lipid accumulation and therefore is suggested to be atherogenic. We investigated the sialic acid content of total LDL and its subfractions, and their relations to lipoprotein kinetics in 22 subjects with primary moderate hypercholesterolemia (IIa) and in 21 subjects with combined hyperlipidemia (IIb) matched for age, sex, BMI and the frequency of coronary artery disease. Sialic acid to protein ratio decreased gradually from VLDL and IDL to light and dense LDL and HDL, but was high in very dense LDL probably due to presence of Lp(a). Sialic acid to apo B ratio was significantly lower in dense and very dense subfractions of IIb than IIa. The sialic acid/apo B ratios of dense and very dense LDL subfractions were interrelated and were negatively associated with their cholesterol and triglyceride concentrations, and with the transport rate (TR) for dense LDL apo B. The only metabolic variable differing between the groups was the TR for dense LDL apo B, which was significantly higher in IIb vs. IIa. In addition, the TR for dense LDL apo B was positively associated with the esterification percentage of LDL cholesterol. In conclusion, low sialic acid content in dense and very dense LDL subfractions was associated with enhanced TR for LDL apo B and type IIb dyslipidemia.

Simvastatin compared to fluvastatin in the reduction of serum lipids and apolipoproteins in patients with ischaemic heart disease and moderate hypercholesterolaemia.

OBJECTIVE: Inhibitors of HMG-CoA reductase are widely used for the treatment of hypercholesterolaemia and have recently been shown in the Scandinavian Simvastatin Survival Study (4S), to reduce coronary mortality as well as total mortality in CH D patients. Although a couple of studies have already established the efficacy ratio between simvastatin and fluvastatin, one of the newest members of this class, we considered it to be important to verify the comparative efficacy in patients with coronary artery disease in the same type of patients that were included in 4S particularly since the previous studies include rather few patients with CHD, 17-28% only. METHODS AND RESULTS: Three Scandinavian lipid clinics participated in this randomized double-blind study and enrolled a total of 113 hypercholesterolaemic patients with a profile similar to the 4S patients, i.e. either a history of typical angina pectoris lasting at least three months or a myocardial infarction at least six months before the study and with moderate hypercholesterolaemia, total serum cholesterol between 5.5 and 8.0 mmol/l. After a diet run-in period lasting at least 8 weeks, followed by a two week placebo period, patients received treatment with active drug for a 16 week period, with measurement of lipids using the same technique and laboratory as was used in 4S. Patients were randomly assigned to simvastatin 20 mg or fluvastatin 20 mg. If after 6 weeks of double-blind treatment, the 4S total cholesterol target of < or = 5.2 mmol/l total serum cholesterol had not been reached, the dose was doubled at the next visit, i.e. at week 10 based upon blinded titration information from the central lipid laboratory like in the 4S study. A final assessment of serum lipids and lipoproteins was made at week 16. The mean percent reductions in LDL-cholesterol from baseline were 37% and 40% in the simvastatin group compared to 19% and 26% in the fluvastatin group, at weeks 10 and 16, respectively (p < 0.001). In the simvastatin group 18 percent of the patients needed an increase in the dose to 40 mg compared to 63 percent in the fluvastatin group (p < 0.001). At the 20 mg dosage, simvastatin produced a lowering of LDL-cholesterol approximately twice that of fluvastatin 20 mg and resulted in 82% of patients achieving the cholesterol target levels as defined in the 4S study, compared to 19% for fluvastatin. All other recorded lipid variables showed differences which favoured simvastatin over fluvastatin at comparable doses including serum triglyceride reductions where serum triglycerides at week 6 were borderline significantly different between the two groups. Patient tolerability of the two drugs was similar. CONCLUSION: At the recommended doses in patient with angina or a prior MI and mild to moderate hypercholesterolaemia simvastatin is considerably more effective than fluvastatin in lowering serum total cholesterol, LDL-cholesterol as well as other serum lipid risk factors. At an average titrated dose of 32 mg less than 50% of the fluvastatin patients reached the 4S cholesterol target of < 5.2 mmol/l compared to 89% of the simvastatin patients at an average dose of 23 mg daily and only 13% of the fluvastatin patients achieved an LDL-cholesterol reduction of at least 40% compared to 63% of the simvastatin patients.

Cholesterol metabolism and serum and biliary noncholesterol sterols in gallstone patients during simvastatin and ursodeoxycholic acid treatments.

Effects of long-term high-dose ursodeoxycholic acid (UDCA) and simvastatin treatments on cholesterol metabolism and biliary lipid compositions were compared in patients with cholesterol gallstones. Absorption and synthesis of cholesterol, serum and biliary noncholesterol sterols and lipids were determined in 14 patients randomized to UDCA (23-25 mg/kg/d) or simvastatin (40 mg/d) for 1 year. Simvastatin reduced serum low-density lipoprotein cholesterol by 55%, and UDCA, by 9%. Cholesterol absorption was decreased (35%) by UDCA, but nonsignificantly increased by simvastatin (P < .05 for difference of changes caused by the two drugs). Whole-body synthesis and biliary output of cholesterol were both significantly decreased only by UDCA. In addition, UDCA inconsistently increased the proportions of serum and biliary precursor sterols of cholesterol, known to reflect cholesterol synthesis, but did not affect their biliary secretions. Simvastatin, however, dramatically reduced serum and also biliary cholesterol precursor sterol proportions and their biliary secretions and increased proportions of serum and biliary plant sterols and cholestanol, known to reflect cholesterol absorption, but had no effect on their biliary secretion. Only UDCA significantly decreased the molar percentage of cholesterol, the lithogenic index, and the cholesterol/phospholipid (CH/ PL) ratio in bile, whereas both treatments inconsistently decreased the vesicular CH/PL ratio (P < .07 in both groups). It is concluded that both drugs decreased serum cholesterol and inhibited cholesterol synthesis, but had a differing influence on precursor sterols and the absorption of cholesterol. UDCA had more beneficial effects than simvastatin on the antilithogenic properties of bile.

The sedimentable sterols in gallstone patients before and during ursodeoxycholic acid and simvastatin treatments.

BACKGROUND: The insoluble material in supersaturated bile is prerequisite for the formation of gallstones. We therefore studied the biliary precipitable and soluble cholesterol and noncholesterol sterols, including the cholesterol precursor sterols (including lanosterol and lathosterols), and the plant sterols campesterol and sitosterol, and cholestanol, which usually reflect cholesterol synthesis and absorption, respectively, before and after a 6-month treatment with ursodeoxycholic acid (UCDA), 15.4 +/- 4 mg/kg/day (standard error of the mean) or simvastatin (40 mg/day) in 21 patients with cholesterol gallstones, to obtain further information about the factors contributing to the formation of gallstones. METHODS: The sediment and supernatant fractions of duodenal bile samples were separated by ultracentrifugation and analyzed with gas-liquid chromatography. RESULTS: At the base line (n = 21) 50% +/- 3% of biliary cholesterol and a variable amount of the noncholesterol sterols (from 14% of lanosterol to 62% of cholestanol) were in the sediment fraction. The pattern of the noncholesterol sterols in the sediment resembled that of gallstones described previously. At base line body mass index was positively related to the percentage of precipitable cholesterol in bile (r = 0.46, P < 0.05), and the serum sitosterol proportion negatively related to the molar percentage of biliary cholesterol and positively to that of bile acids (r = -0.46 and r = 0.50, P < 0.05 for both). UDCA decreased the precipitable percentage of cholesterol from 46% to 31% (P < 0.03) and simvastatin from 57% to 42% (P = 0.05). Both drugs also decreased the precipitable percentages of lathosterols and cholestanol while increasing that of lanosterol. In relation to cholesterol, the sediment to supernatant ratios of all methylsterols were increased, whereas those of polar lathosterols tended to decrease during UDCA treatment. CONCLUSIONS: Patients with high body mass index have more precipitable cholesterol in their bile. Although both UDCA and simvastatin decreased the precipitable cholesterol, the bile still contained one-third of its cholesterol in the sedimentable form.

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.

Noncholesterol sterols in bile and stones of patients with cholesterol and pigment stones.

Human bile and cholesterol gallstones contain sterols including methylated (lanosterol and other dimethyl and monomethyl sterols), and demethylated cholesterol precursor sterols (delta 8-lathosterol, lathosterol, and desmosterol), plant sterols (campesterol and sitosterol), and cholestanol. The aim of the study was to analyze the noncholesterol sterols in gallbladder bile and stones from female and male patients with cholesterol stones (CS) and pigment stones (PS) to ascertain whether any sterol fraction contributes to the gallstone formation. Classification of gallstones to CS and PS was performed on the basis of the stone cholesterol content. The study group consisted of 165 consecutive cholecystectomized patients, 150 with CS and 15 with PS. Bile acids and sterols were quantitated using gas-liquid chromatography (GLC). The biliary lipid and noncholesterol sterol/cholesterol proportions were similar in the CS and PS patients. The proportions of methylated and plant sterols were significantly lower in the CS than in bile, whereas those of delta 8-lathosterol, lathosterol, and cholestanol were significantly higher. The PS, in contrast to the CS, were neither sex nor weight related. The bile acid and phospholipid concentrations and the proportions of lanosterol, delta 8,24-dimethylsterol, and sitosterol were up to 50 times higher and those of delta 8-lathosterol and lathosterol twice lower in the PS than in the CS. The results suggest that, in general, the stones with low cholesterol content are proportionately richer in nonpolar precursor and plant sterols and lower in demethylated precursors, the situation being opposite for the CS. The stone/bile ratios suggest that in both stone groups, but especially in the CS, levels of the polar precursor sterols and cholestanol were enriched in the stone, whereas levels of the nonpolar precursor sterols, and to a lesser extent plant sterols, were not enriched in the stone despite their high biliary proportions.