| For medical practitioners and the general public - Cholesterol Journal Article Catalog. |
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| An evaluation of efficacy of cigarette smoking cessation in preventing low levels of serum high-density lipoprotein (HDL) cholesterol Nishihara, H., Y. Takashima, et al. (1991), Sangyo Igaku 33(4): 231-40. Abstract: Correlation of serum high-density lipoprotein cholesterol (HDL-C) with cigarette smoking and alcohol consumption habit was investigated in 562 male office workers aged 31 to 60 yr. HDL-C concentrations were found to be positively associated with alcohol consumption in subjects with relative weight below 10%, but a positive association was not observed in obese subjects having relative weight of 10% or above. In contrast, HDL-C levels were significantly lower in smokers than in non-smokers regardless of obesity. The effectiveness of smoking cessation in preventing low levels of serum HDL-C was estimated by comparing prevalence rates of HDL-C levels lower than an arbitrarily determined HDL-C cutoff value in smokers with those in non-smokers. The estimation was made with unadjusted subjects and also with subjects adjusted for age, relative weight and alcohol consumption. The effectiveness was found to be considerably high in heavy smokers having lower HDL-C levels (less than or equal to 35 mg/dl) with or without hypercholesterolemia (greater than or equal to 220 mg/dl) and further remarkably high in all smokers having hypertriglyceridemia (greater than or equal to 300 mg/dl) besides lower HDL-C levels. It is therefore expected that health education focused on stopping smoking can produce favorable alterations in HDL-C for preventing coronary heart disease, especially in heavy smokers having low serum HDL-C levels concomitant with hypercholesterolemia and/or hypertriglyceridemia. |
| An evaluation of the Reflotron for the determination of plasma cholesterol in capillary blood. Effect of operator variability Bhatnagar, D. and P. N. Durrington (1993), Occup Med (Lond) 43(2): 69-72. Abstract: The availability of portable analysers potentially puts the detection of individuals with high serum cholesterol levels on a similar footing to that of high blood pressure. The Reflotron, which can make cholesterol measurements on capillary blood samples without the need for centrifugation, has been evaluated in clinical practice. In 94 consecutive patients capillary blood was used for the determination of serum cholesterol by the Reflotron, by a laboratory technician (n = 37) and by a nursing sister (n = 57). Venous blood was also taken from the same patients within a few minutes of the capillary sample for enzymic determination of serum cholesterol at the hospital laboratory. Overall, the Reflotron values were about 0.6 mmol/l lower than those obtained at the hospital laboratory. The accuracy and precision of the results obtained by the nurse were poorer than those obtained by the technician, even though the nurse had attended a three day training course. Our results indicate that the Reflotron is a suitable instrument for use in screening for serum cholesterol, provided personnel operating the machine have adequate training and experience, and provided it is borne in mind that the results obtained may be slightly lower than standard laboratory methods. |
| An evaluation of the Reflotron portable analyzer for cholesterol determination in primary care Torres Garrido, M., E. Aragones Benaiges, et al. (1990), Aten Primaria 7 Spec No: 34-7. Abstract: We have evaluated serum cholesterol in a primary care center with a recently introduced portable analyzer: Reflotron (Boehringer Mannheim). The linearity and exactitude were investigated with Hitachi 704 (Boehringer Mannheim) used in the reference laboratory. Accuracy was also tested. We found a good accuracy after repeated analysis (n = 30) of two control sera with a variation coefficient of 2.77% in the first (mean = 125.14 mg/dl, SD 3.47) and 2.94% (mean = 254.53 mg/dl, SD 7.49) in the second. We found an overall lack of accuracy of Reflotron with a more pronounced negative bias in capillary blood (mean d = 30.93 mg/dl, dSE 3.25) than in serum (mean d = dSE 1.12). We found a positive linear correlation both using serum (r = 0.9845; n = 45) and capillary blood (r = 0.9094; n = 30). We feel that Reflotron is useful for primary care due to its good accuracy and linearity regarding the reference method, but its inexactitud should be taken into account. We emphasize the need for quality control to investigate its limitations when the results are analyzed. |
| An experimental evaluation of an incentive program to reduce serum cholesterol levels among health fair participants Francisco, V. T., A. L. Paine, et al. (1994), Arch Fam Med 3(3): 246-51. Abstract: OBJECTIVE: To evaluate the impact of a health fair and incentive program on the reduction of serum cholesterol levels among participants. DESIGN: Pretest-posttest control group design, with a 6-month delay between pretest and posttest screenings. SETTING: Health fair program for employees of a large midwestern school district. PARTICIPANTS: Volunteer sample among persons with serum cholesterol levels above 5.17 mmol/L (200 mg/dL). Participants were randomly assigned to experimental (N = 29) and comparison groups (N = 34). INTERVENTION: The intervention consisted of four components: a health fair, health risk information, announcement of follow-up screening, and an incentive program. The incentive program consisted of five $100 cash prizes for reducing serum cholesterol levels by 20% or below 5.17 mmol/L (200 mg/dL). The comparison group received only the first three components. MAIN OUTCOME MEASURE: Serum cholesterol levels were measured by a venipuncture, nonfasting, chemical analysis process. RESULTS: The experimental group showed a 13.2% reduction in serum cholesterol levels, and the comparison group exhibited an 11.3% reduction (P <.05). CONCLUSIONS: A health fair, consisting of information on the level of risk and how to reduce risk, and announcement of follow-up screening and incentives can reduce the risk for cardiovascular disease. |
| An external, oversized, porous polyester stent reduces vein graft neointima formation, cholesterol concentration, and vascular cell adhesion molecule 1 expression in cholesterol-fed pigs Angelini, G. D., C. Lloyd, et al. (2002), J Thorac Cardiovasc Surg 124(5): 950-6. Abstract: BACKGROUND: Reducing neointima formation and atherosclerosis are key goals in preventing late vein graft failure. Although pharmacologic and mechanical solutions have been proposed, the demonstration that these influence both aspects of vein graft pathology have been lacking. Supporting grafts externally with an oversized, highly porous polyester stent dramatically reduces neointima formation in normocholesterolemic pigs. However, its effects in the presence of hypercholesterolemia are unknown. METHODS: We compared wall thickening, cholesterol concentration, foam-cell formation, and the expression of the leukocyte adhesion molecule vascular cell adhesion molecule 1 after 3 months in stented and unstented saphenous vein interposition grafts into the carotid arteries of pigs fed cholesterol to cause modest hypercholesterolemia (11.2 +/- 1.2 mmol/L). RESULTS: Stenting reduced neointima formation from 5.6 +/- 0.4 to 1.2 +/- 0.2 mm(2) (n = 7; P <.00002, paired t test) and graft cholesterol concentration from 4.7 +/- 1.2 to 2.1 +/- 1.3 mg/g wet weight (P <.02). Foam cells were observed in unstented grafts (mean, 1.5% +/- 0.5% of all cells) but never in stented grafts. Vascular cell adhesion molecule 1 was strongly expressed in 53% +/- 8% of intimal and medial cells in unstented grafts but was weakly expressed in only 19% +/- 3% (n = 4, P <.05) of stented grafts. CONCLUSIONS: We conclude that external stenting with polyester favorably influences both neointima formation and early atherosclerosis, both of which are key aspects of vein graft disease, and that decreased expression of vascular cell adhesion molecule 1 is part of the underlying mechanism. |
| An extract of soy flour influences serum cholesterol and thyroid hormones in rats and hamsters Balmir, F., R. Staack, et al. (1996), J Nutr 126(12): 3046-53. Abstract: The effects of an ethanol-acetone extract from soy flour on serum lipids and thyroid hormones were studied in rats and hamsters. In Study 1, male Sprague-Dawley rats were fed diets containing protein from ethanol-acetone extracted isolated soy protein (ISP-), nonextracted ISP (ISP), casein (casein-), or casein to which 0.36 mg ethanol-acetone extract/g protein was added (casein+). Rats fed either ISP-containing diet had lower serum total cholesterol concentrations compared with those fed either casein diet (P < 0.05). Lower serum LDL-cholesterol concentrations were present in rats fed either ISP-containing diet and in those fed casein+ compared with those fed casein- (P < 0.05). Adding the extract to casein (casein+) produced higher serum thyroxine concentration and free thyroxine indices compared with all other groups (P < 0.05). In Study 2, male Golden Syrian hamsters were fed experimental diets containing protein from ISP, ISP with added ethanol-acetone extract (0.36 mg extract/g protein; ISP+), casein-, casein+ (0.36 mg extract/g protein), or casein with twice the level of extract (0.72 mg/g protein; casein++). Lower serum total cholesterol and LDL (LDL + VLDL + IDL) cholesterol concentrations were observed in hamsters fed ISP, ISP+ or casein+ compared with those fed casein- (P < 0.05). Addition of the extract at higher levels to casein (casein++) did not lower serum lipids relative to those fed casein-. Serum thyroxine concentration and the free thyroxine index were greater in both ISP groups as well as in hamsters fed casein++ compared with those fed casein- or casein+ (P < 0.05). In conclusion, both studies show that protein from soybeans decreases serum total and LDL cholesterol while the effects on thyroxine are different in rats and hamsters. It is also apparent that the ethanol-acetone extract of soy flour produces changes in serum cholesterol, particularly in the LDL fraction in both species. |
| An extraction/enzymatic procedure for serum cholesterol measurement: evaluation of performance characteristics Franzini, C. and P. Luraschi (1990), J Clin Chem Clin Biochem 28(12): 913-8. Abstract: The performance characteristics of an extraction/enzymatic procedure for serum cholesterol measurement were evaluated. The procedure is substantially derived from the accepted reference method as standardized by the Centers for Disease Control, substituting the enzymatic reaction for the Liebermann-Burchard reaction. Imprecision (CV) was consistently less than 1.5%, and accuracy was comparable to that of the definitive isotope dilution mass spectrometry method and the accepted reference method. Direct comparison of the enzymatic with the Liebermann-Burchard reaction, using a set of 50 human sera, revealed about -0.05 mmol/l constant bias of the former versus the latter, this being possibly due to higher specificity of the enzymatic reaction. As compared with the accepted reference method, the method described is characterized by higher practicability, the reagent being easier to prepare and to handle, and generating a more stable, chemically defined end-product. |
| An HL-60 variant cell line defective in cholesterol synthesis Tsuyuki, M. and K. Yoshihara (1995), Cell Struct Funct 20(1): 13-21. Abstract: Human promyelocytic leukemia cell line, HL-60, is known to proliferate exponentially in a serum-free synthetic medium supplemented with insulin and transferrin (BREITMAN, T.R. et al. (1980). Exp. Cell. Res., 126: 494-498). Among four HL-60 cell lines tested in this medium (serum-free medium), however, a cell line, HL-60/Biken ceased to proliferate after two days culture and most of the cells died within a week. Addition of purified serum lipoprotein (LDL or HDL) to the serum-free medium almost completely restored the proliferating activity of the cells. Total lipids extracted from the lipoproteins could replace the lipoproteins in promoting cell proliferation. Among various lipid components of the lipoproteins, only cholesterol showed a high stimulatory effect on cell proliferation, whereas other lipids tested were ineffective, except for sphingomyelin, cerebroside, and phosphatidic acid which showed limited stimulatory effects. As for the intermediates of cholesterol biosynthesis, desmosterol was also effective, whereas lanosterol was rather inhibitory. Chromatographic analyses of the lipids synthesized by HL-60/Biken cells and wild type cells (HL-60/RCB) cultured in serum-free medium, clearly demonstrated that, in HL-60/Biken cells, cholesterol synthesis was almost completely blocked and lanosterol was accumulated 10-fold that in wild type HL-60/RCB cells. All of these results indicate that HL-60/Biken is a variant cell line defective in cholesterol synthesis in the process synthesizing desmosterol from lanosterol. The variant HL-60 cells showed a marked resistance to cell differentiation along both monocytic and granulocytic pathways when compared with wild type HL-60 cells. The cell line may be useful for the study of the role of cholesterol in cell differentiation. |
| An HPLC-GC/MS reference method for serum total cholesterol with control for ester hydrolysis Linnet, K. (1994), Clin Biochem 27(3): 177-82. Abstract: Currently used isotope-dilution mass spectrometry methods for serum total cholesterol are performed without control in each sample for completeness of hydrolysis of cholesterol esters. In order to monitor this step in the analysis, we developed a method based on both high-pressure liquid chromatography (HPLC) and gas chromatography/mass spectrometry (GC/MS). 13C3-cholesterol and cholesteryl 1-14C oleate were added to serum that was saponified and extracted into hexane. The extract was subjected to HPLC with collection of the fractions corresponding to cholesterol and cholesteryl oleate. The radio-activity of the latter was counted in order to estimate the nonhydrolysed fraction that on average amounted to less than 0.1% for commonly used ester hydrolysis procedures. The cholesterol fraction was subjected to GC/MS for quantitation using the traditional isotope-dilution principle. Evaluation of accuracy by assaying sera from the National Institute of Standards and Technology showed a deviation from the target value of < 1% with a coefficient of variation of < or = 1.0%. In conclusion, the present reference method for serum total cholesterol assures results based on complete hydrolysis of the cholesterol ester fraction. |
| An improved HPLC method to purify erythrocyte cholesterol for estimation of in vivo cholesterol synthesis using the deuterium method Wong, W. W., D. L. Hachey, et al. (1994), Appl Radiat Isot 45(4): 529-33. Abstract: We report on an improved HPLC method to purify erythrocyte cholesterol for use in measuring in vivo cholesterol synthesis from 2H2O. The new procedure uses a smaller compression cartridge column at a flow rate of 3 mL/min. The new method reduces by almost tenfold the amount of solvent required to maintain the analytical purity of the isolated cholesterol. |
| An improved method for quantification of cholesterol and cholesteryl esters in human monocyte-derived macrophages by high performance liquid chromatography with identification of unassigned cholesteryl ester species by means of secondary ion mass spectrometry Cullen, P., M. Fobker, et al. (1997), J Lipid Res 38(2): 401-9. Abstract: The measurement of cholesteryl esters in human monocyte-derived macrophages using previously described high performance liquid chromatography methods is hampered by the presence in these cells of large amounts of triglycerides. We present a simple reversed phase high performance liquid chromatography protocol for quantification of cholesterol and cholesteryl esters in human monocyte/macrophages or other triglyceride-rich cells. Our method requires only lipid extraction and hydrolysis of triglycerides using a solution of ethanolic potassium hydroxide and is of sufficient sensitivity to allow measurement in 10(5) cells. Use of this protocol led to the isolation of eight previously unassigned cholesteryl ester peaks comprising 16% of the total cholesteryl ester content of human monocyte-derived macrophages. Using time-of-light secondary ion mass spectrometry and synthesized authentic standards, seven of these peaks were found to comprise cholesterol esterified with polyunsaturated n-3 (omega 3) (cholesteryl eicosapentaenoate, docosatrienoate, docosapentaenoate, and docosahexaenoate) and n-6 (omega 6) (cholesteryl docosatetraenoate, eicosadienoate, and eicosatrienoate) fatty acids. The remaining peak was shown to be the cholesteryl ester of n-7 (omega 7) palmitoleic acid by comparison with a commercially available standard. The identification of all the cholesteryl esters in cholesterol-loaded human monocyte-derived macrophages will assist future studies of lipid metabolism in these cells. |
| An improved method for the microscale preparation and characterization of hapten-protein conjugates: the use of cholesterol as a model for nonchromophore hydroxylated haptens Naar, J., P. Branaa, et al. (1999), Bioconjug Chem 10(6): 1143-9. Abstract: A minute amount (0.446 micromol) of cholesterol (Chol) was converted into an hemisuccinate derivative (Chol HS) using an excess of succinic anhydride. The optimal conditions for synthesis of Chol HS were explored by checkerboard experiments in which various succinic anhydride/Chol molar ratios ranging from 5:1 to 30:1 were assayed over a wide temperature range (50-85 degrees C) and for various incubation times (3-8 h). Total conversion was obtained at the higher reagent ratios, temperatures, and incubation times. Subsequently, this carboxylic derivative was first covalently linked to bovine serum albumin (BSA) then to various proteins (casein, ovalbumin, and hemocyanins) or to a synthetic homopolymer (poly-DL-Lysine) via a modified version of the mixed anhydride method of Erlanger, performed in a reversed micellar medium. The assessment of the number of haptenic groups per mole of BSA (epitope density) was achieved chromatographically by two methods according to a Chol standard curve established at 207 nm with linearity in the range 0-50 microg. These procedures involving an alkaline hydrolysis of a sample of either the conjugate (direct method) or the unreacted Chol HS (indirect method) yielded an acceptable level of agreement and concordant results in all cases. The influence of the activated hapten/BSA molar ratio on the coupling efficiency was investigated by the direct method within the range 10:1 to 250:1. Using the optimal conditions determined for Chol HS synthesis (a molar reagent ratio of 30:1 with incubation at 65 degrees C for 6 h) and for BSA haptenation (a 100-fold molar excess of activated hapten, with a carrier stock concentration of 5 mg/mL), epitope density of the conjugates lied between 23 and 27. By reacting the same amount of activated hapten (approximately 216 microg) with identical amounts of various carriers (300 microg), conjugation efficiency was found similar on a microgram of Chol bound per milligram of carrier basis. This simple and reproducible conjugation and analysis procedures should provide a general method applicable to poorly available and weakly immunogenic haptens bearing hydroxyl groups such as polyether-type marine toxins. |
| An improved method of cholesterol determination in egg yolk by high performance liquid chromatography Zhang, R., L. Li, et al. (1998), Se Pu 16(2): 91-4. Abstract: An improved method for cholesterol determination in egg yolk is reported in this paper. Egg yolk was first diluted. Cholesterol was then extracted with ethyl ether and petroleum ether, and quantified by reversed phase liquid chromatography on a Zorbax ODS column (0.46 mm x 15 cm, 5-6 microns) using a mobile phase of acetonitrile and 2-propanol (4:1) with a flow rate of 0.6 mL/min. A linear correlation was observed between 0.05-0.40 g/L of cholesterol. The determination limit was 0.02 g/L. This proposed method of HPLC determination of egg yolk without saponification is superior to colorimetric determination on the sample with saponification, and comparable to HPLC determination with saponification of the egg yolk sample in terms of reliability. No difference in final results was observed between egg yolk sample with saponification and the same sample without saponification. Rapid and reproducible quantification of cholesterol in egg yolk can be completed with this new method. Omission of saponification has made this proposed method more convenient than those ever reported, and can be used in yolk cholesterol study with greater ease. |
| An improved ultracentrifugation method for the separation of cholesterol carriers in bile Ayyad, N., B. I. Cohen, et al. (1996), Lipids 31(6): 657-60. Abstract: Vesicles and micelles, the major carriers of cholesterol in bile, play a role in the formation of cholesterol gallstones. A simple and rapid ultracentrifugation method was developed to isolate these biliary cholesterol carriers when only microliter amounts of bile were available. The proposed method employs a 46 to 0% sucrose density gradient, a NVT90 near-vertical rotor, and a centrifugation time of one hour. As little as 25 microL of bile can be used with no disruption of the carriers. The method was validated by comparison with gel filtration column chromatography using 6 mM taurocholate in the elution buffer. The sucrose linear density gradient ultracentrifugation procedure described here is simple, fast, and compares favorably with the gel filtration chromatography method for the separation of cholesterol carriers from bile. |
| An in vitro study of the probiotic potential of a bile-salt-hydrolyzing Lactobacillus fermentum strain, and determination of its cholesterol-lowering properties Pereira, D. I., A. L. McCartney, et al. (2003), Appl Environ Microbiol 69(8): 4743-52. Abstract: This study evaluated the use of a bile-salt-hydrolyzing Lactobacillus fermentum strain as a probiotic with potential hypocholesterolemic properties. The effect of L. fermentum on representative microbial populations and overall metabolic activity of the human intestinal microbiota was investigated using a three-stage continuous culture system. Also, the use of galactooligosaccharides as a prebiotic to enhance growth and/or activity of the Lactobacillus strain was evaluated. Administration of L. fermentum resulted in a decrease in the overall bifidobacterial population (ca. 1 log unit). In the in vitro system, no significant changes were observed in the total bacterial, Lactobacillus, Bacteroides, and clostridial populations through L. fermentum supplementation. Acetate production decreased by 9 to 27%, while the propionate and butyrate concentrations increased considerably (50 to 90% and 52 to 157%, respectively). A general, although lesser, increase in the production of lactate was observed with the administration of the L. fermentum strain. Supplementation of the prebiotic to the culture medium did not cause statistically significant changes in either the numbers or the activity of the microbiota, although an increase in the butyrate production was seen (29 to 39%). Results from this in vitro study suggest that L. fermentum KC5b is a candidate probiotic which may affect cholesterol metabolism. The short-chain fatty acid concentrations, specifically the molar proportion of propionate and/or bile salt deconjugation, are probably the major mechanism involved in the purported cholesterol-lowering properties of this strain. |
| An increase in plasma cholesterol independent of thyroid function during long-term amiodarone therapy. A dose-dependent relationship Wiersinga, W. M., M. D. Trip, et al. (1991), Ann Intern Med 114(2): 128-32. Abstract: OBJECTIVE: To determine whether long-term amiodarone treatment is associated with a rise in plasma cholesterol, and, if so, to analyze its relation with thyroid function. DESIGN: Consecutive entry trial, including cardiac patients who initiated amiodarone medication but excluding those with abnormal thyroid function (defined as peak thyroid-stimulating hormone TSH response to thyrotropin-releasing hormone TRH less than 2.8 or greater than 22.0 mU/L) either before or during amiodarone treatment. PATIENTS: Twenty-three patients who remained euthyroid were studied. INTERVENTION: Oral administration of amiodarone (mean duration of treatment, 17 months; range, 6 to 30 months). MEASUREMENTS: Fasting plasma lipids, thyroid hormones, and peak TSH to TRH values were recorded before and every 6 months during amiodarone treatment. RESULTS: Plasma cholesterol gradually increased from 5.1 +/- 0.2 mmol/L before treatment to 6.9 +/- 0.8 mmol/L after 30 months of amiodarone medication (P less than 0.001); the peak TSH response to TRH did not change. When age- and sex-specific reference values were applied, 30% of the patients had cholesterol values above the 75th percentile before treatment; this number rose to 69% after 2 years of treatment. The rise in plasma cholesterol was associated with an equal increase in apoprotein B. Plasma cholesterol was not related to the daily dose of amiodarone or to plasma concentrations of amiodarone, desethylamiodarone, thyroxine (T4), triiodothyronine (T3), or reverse triiodothyronine (rT3). Linear regression analysis indicated a positive relation between plasma cholesterol and the cumulative dose of amiodarone (r = 0.25, P less than 0.05). CONCLUSION: Long-term amiodarone treatment is associated with a dose-dependent increase in plasma cholesterol that is independent of thyroid function. |
| An increase in the production of bile acids by hepatocytes--one of the possible mechanisms of resistance to the development of hypercholesterolemia in rabbits in response to a long-term dietary cholesterol load Lakeev Iu, V., V. A. Kosykh, et al. (1991), Dokl Akad Nauk SSSR 318(3): 749-52. |
| An increased risk of death from ischemic heart disease in men with low blood concentrations of total cholesterol and low-density lipoprotein cholesterol Kalinina, A. M., L. V. Chazova, et al. (1993), Ter Arkh 65(4): 27-32. Abstract: A number of epidemiological surveys have recently established that in populations with the lowest levels of total cholesterol (TC) and LDL cholesterol (LDLC) death rates grow due to both malignant and cardiovascular diseases. The results of a detailed study on multifactor prevention of coronary heart disease (CHD) in an open population of Moscow males aged 40-59 to elucidate the relations between TC, HDL cholesterol, LDLC and CHD mortality demonstrated that low levels of TC are markers, but not a factor of CHD and sudden death risk in low-educated subjects free of CHD symptoms. When planning mass measures to primarily prevent CHD, subjects with low cholesterol levels should be given a special care as well as those with hypercholesterolemia. |
| An independent, inverse association of high-density-lipoprotein-cholesterol concentration with nonadipose body mass Pietrobelli, A., R. C. Lee, et al. (1999), Am J Clin Nutr 69(4): 614-20. Abstract: BACKGROUND: Increasing body mass index (BMI) is associated with progressively lower serum HDL-cholesterol concentrations, although the underlying body-composition compartment accounting for this unfavorable lipid change remains uncertain. OBJECTIVE: Because growing evidence favors a role of lean tissue in HDL homeostasis, the hypothesis was tested that non-adipose tissue components of body mass explain the inverse association of HDL cholesterol and BMI. DESIGN: Fasting serum lipid concentrations and body composition total, subcutaneous, and visceral adipose tissue; adipose tissue-free mass (ATFM); and skeletal muscle by whole-body magnetic resonance imaging and body cell mass by 40K counting) were evaluated in healthy adults. Body-composition compartments were expressed as height2-normalized indexes. RESULTS: An inverse correlation was observed between serum HDL cholesterol and BMI in women (n = 68; R2 = 0.08, P = 0.023) and men (n = 61; R2 = 0.07, P = 0.046). Significant inverse correlations (P = 0.005-0.02) were also observed between HDL cholesterol and nonadipose components (ie, ATFM, skeletal muscle, and body cell mass) but not between HDL cholesterol and any adipose tissue component. The association between HDL cholesterol and ATFM remained significant after serum triacylglycerol was controlled for. When BMI was entered into the HDL cholesterol-ATFM regression model, BMI was not a significant independent variable. The strongest correlate of serum triacylglycerol was visceral adipose tissue (P = 0.002 for both women and men). CONCLUSIONS: Lean tissues and body cell mass appear to account in part for the long-observed inverse association of HDL cholesterol and BMI. These observations suggest a link between nonadipose tissue compartments and the greater cardiovascular risk associated with high BMI. |
| An inhibitor of acylCoA: cholesterol acyltransferase increases expression of ATP-binding cassette transporter A1 and thereby enhances the ApoA-I-mediated release of cholesterol from macrophages Sugimoto, K., M. Tsujita, et al. (2004), Biochim Biophys Acta 1636(1): 69-76. Abstract: The effect of inhibition of acylCoA: cholesterol acyltransferase (ACAT) was studied on high density lipoprotein (HDL) metabolism. An inhibitor of ACAT, MCC-147, was given mouse peritoneal macrophages and expression of ATP-binding cassette transporter A1 (ABCA1) was examined. ABCA1 was increased both at the mRNA and protein levels, only when the cells are cholesterol-loaded and thereby the inhibitor decreased esterified cholesterol and increased unesterified cholesterol. In this condition, the ACAT inhibitor increased reversible binding of apoA-I to the cells and enhanced apoA-I-mediated release of cellular cholesterol and phospholipid, but did not influence nonspecific cellular cholesterol efflux to lipid microemulsion. It was therefore concluded that the ACAT inhibitor increased the release of cholesterol from the cholesterol-loaded macrophages by increasing the expression of ABCA1, putatively through shifting cholesterol distribution from the esterified to the free compartments. |