| For medical practitioners and the general public - Cholesterol Journal Article Catalog. |
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| HDL-cholesterol: role of its dosage in the assessment of cardiovascular risk Guinchard-Foulon, E., C. Rodriguez-Lafrasse, et al. (2003), Ann Biol Clin (Paris) 61(5): 549-56. Abstract: The interest of HDL-cholesterol (HDLC) to evaluate a cardiovascular risk has been studied since many years. According to Framingham Heart studies, this factor is inversely correlated to a future ischaemic heart disease. At high level, HDLC is considered as a cardiovascular protecting factor, and is known since few years as "good cholesterol". In the year 2000, the ANAES (Agence nationale de l'accreditation et evaluation en sante) has redefined the role of HDLC in the exploration of dyslipidaemia. In the case of a cardiovascular-risk history, HDLC, with total cholesterol, triglycerides, and LDL-cholesterol (by Friedewald method) will be analyzed. Usually, HDLC is not very accessible to conventional treatments. So, according to ANAES, the treatment of dyslipidaemia will be based on LDL-cholesterol levels only. Nevertheless, HDLC is a major lipid factor to evaluate a cardiovascular risk. The object of this review is, on one hand, to situate HDLC in the evaluation of cardiovascular risk, by showing its key role in lipid metabolism, and, on the other hand, to report the main direct assays of this parameter. |
| HDL-cholesterol--active or passive participant in the pathogenesis of atherosclerosis? (II) Artenie, A., R. Artenie, et al. (2004), Rev Med Chir Soc Med Nat Iasi 108(3): 503-8. Abstract: It is known that high sanguin levels of cholesterol and LDL-cholesterol (LDLc) have an important role in the pathogenesis of atherosclerosis. The treatment of hypercholesterolemia with statins and/or with fibrates have had beneficial effects on coronary heart disease and on other localization of atherosclerosis. The decreased of cholesterol and LDL-cholesterol is the most important effect of this treatment. The epidemiological studies have revealed that the treatment with statins and/or with fibrates produce an increase of HDL-cholesterol (HDLc), which is also very important in the regression of atherosclerosis. We tried in this review to explain the mechanisms of the increase of HDL-cholesterol, in concordance with the data from literature. |
| HDL-cholesterol-raising effect of orange juice in subjects with hypercholesterolemia Kurowska, E. M., J. D. Spence, et al. (2000), Am J Clin Nutr 72(5): 1095-100. Abstract: BACKGROUND: Orange juice-a rich source of vitamin C, folate, and flavonoids such as hesperidin-induces hypocholesterolemic responses in animals. OBJECTIVE: We determined whether orange juice beneficially altered blood lipids in subjects with moderate hypercholesterolemia. DESIGN: The sample consisted of 16 healthy men and 9 healthy women with elevated plasma total and LDL-cholesterol and normal plasma triacylglycerol concentrations. Participants incorporated 1, 2, or 3 cups (250 mL each) of orange juice sequentially into their diets, each dose over a period of 4 wk. This was followed by a 5-wk washout period. Plasma lipid, folate, homocyst(e)ine, and vitamin C (a compliance marker) concentrations were measured at baseline, after each treatment, and after the washout period. RESULTS: Consumption of 750 mL but not of 250 or 500 mL orange juice daily increased HDL-cholesterol concentrations by 21% (P: < 0.001), triacylglycerol concentrations by 30% (from 1.56 +/- 0.72 to 2.03 +/- 0.91 mmol/L; P: < 0.02), and folate concentrations by 18% (P: < 0.01); decreased the LDL-HDL cholesterol ratio by 16% (P: < 0.005); and did not affect homocyst(e)ine concentrations. Plasma vitamin C concentrations increased significantly during each dietary period (2.1, 3.1, and 3.8 times, respectively). CONCLUSIONS: Orange juice (750 mL/d) improved blood lipid profiles in hypercholesterolemic subjects, confirming recommendations to consume >/=5-10 servings of fruit and vegetables daily. |
| HDL-mediated cholesterol uptake and targeting to lipid droplets in adipocytes Dagher, G., N. Donne, et al. (2003), J Lipid Res 44(10): 1811-20. Abstract: Adipocytes express high levels of the HDL scavenger receptor class B type I in a differentiation-dependent manner. We thus have analyzed the routes of HDL cholesterol trafficking at different phases of adipocyte differentiation in the 3T3-L1 cell line. One novel and salient feature of this paper is the observation of a widespread distribution in the cell cytoplasm of Golgi markers, caveolin-2, and a fluorescent cholesterol analog NBD-cholesterol (NBD-chol), observed in the early phases of adipocyte formation, clearly distinct from that observed in mature fat cells (i.e., with fully formed lipid vesicles). Thus, in cells without visible lipid droplets, Golgi markers (Golgi 58K, Golgin 97, trans-Golgi network 38, Rab 6, and BODIPY-ceramide), caveolin-2, and NBD-chol all colocalize in a widespread distribution in the cell. In contrast, when lipid droplets are fully formed at latter stages, these markers clearly are distributed to distinct cell compartments: a compact juxtanuclear structure for the Golgi markers and caveolin-2, while NDB-chol concentrates in lipid droplets. In addition, disorganization of the Golgi using three different agents (Brefeldin, monensin, and N-ethyl-maleimide) drastically reduces NBD-chol uptake at different phases of adipocyte formation, strongly suggesting that the Golgi apparatus plays a critical role in HDL-mediated NBD uptake and routing to lipid droplets. |
| HDL-mediated efflux of intracellular cholesterol is impaired in fibroblasts from Tangier disease patients Rogler, G., B. Trumbach, et al. (1995), Arterioscler Thromb Vasc Biol 15(5): 683-90. Abstract: To further elucidate the cellular mechanisms leading to HDL deficiency in Tangier disease, HDL-mediated cholesterol efflux was studied in cultured skin fibroblasts from Tangier patients. Both Tangier and control fibroblasts show specific saturable binding of HDL3 to the cell membrane (Bmax = 70 and 52 ng/mg protein, respectively; Kd = 8.8 and 10.6 micrograms/mL, respectively). There was no appreciable uptake of HDL3 by Tangier and control fibroblasts, indicating that cholesterol efflux from fibroblasts occurs at the cell membrane. When cellular cholesterol was labeled to equilibrium by 14Ccholesterol incubation for 48 hours at 37 degrees C, HDL3-mediated cholesterol efflux from Tangier fibroblasts was only 50% of control fibroblasts. To define this abnormality in HDL3-mediated cholesterol efflux more precisely, several additional experiments were performed. First, membrane desorption of cholesterol was determined after cell membranes were labeled with 14Ccholesterol for 3 hours at 15 degrees C. With this labeling protocol, there was no difference in HDL3-mediated cholesterol efflux between control and Tangier fibroblasts. Second, efflux of newly synthesized sterols was determined after incorporation of the precursor 14Cmevalonolactone. Under these conditions, specific HDL3-mediated efflux of sterols was almost absent in Tangier fibroblasts. Third, cells were labeled by incubation with reconstituted 3Hcholesteryl-linoleate-LDL. Efflux of LDL-derived cholesterol was only slightly reduced for the first 4 hours of incubation. After 12 hours, there was no difference between control and Tangier cells. The combined data indicate that the reduced efflux of cholesterol from Tangier fibroblasts observed after homogeneous labeling is due to severely reduced efflux of newly synthesized sterol.(ABSTRACT TRUNCATED AT 250 WORDS) |
| Head-specific mannose-ligand receptor expression in human spermatozoa is dependent on capacitation-associated membrane cholesterol loss Benoff, S., I. Hurley, et al. (1993), Hum Reprod 8(12): 2141-54. Abstract: D-Mannose binding lectins appear on the human sperm head following in-vitro incubation under capacitating conditions. Surface expression of lectin is dependent on reduction of the sterol content of sperm membranes. Mannose-specific lectin distribution over the head differs in acrosome-intact and acrosome-reacted spermatozoa. Sugar competition experiments show that mannose is the only saccharide competitive with D-mannosylated albumin binding and that free mannose induces an acrosome reaction in capacitated spermatozoa. A total of 183 men with normozoospermic semen parameters were screened for the ability of their spermatozoa to bind fluorescein isothiocyanate (FITC)-labelled mannosylated albumins, before and after incubation in vitro. The spermatozoa from 176 men 'responded' to incubation by exhibiting time-dependent increases in head-directed mannosylated albumin binding, accompanied by increases in the percentage of spermatozoa showing spontaneous acrosome loss. Motile spermatozoa from the remaining seven men failed to express mannose-lectin binding activity after 18 h of incubation and only low percentages of their spermatozoa showed spontaneous acrosome loss. These seven men were classified as 'non-responders'. The relative amounts of non-esterified cholesterol in the sperm membranes of the responder and non-responder males were analysed by gas-liquid chromatography. Responder spermatozoa showed decreases in free cholesterol content whereas non-responder spermatozoa exhibited either no decrease or increases in relative free cholesterol per cell. Fresh swim-up spermatozoa contain sub-plasma membrane stores of mannose lectins which are revealed by FITC-mannosylated albumin labelling before and after removal of the plasma membrane by vortexing. In contrast, the mannose-lectin binding activity of capacitated spermatozoa is entirely limited to the sperm surface. Western blots of proteins isolated from sperm plasma membranes after capacitation revealed two molecular species reactive with polyclonal antibodies against human macrophage mannose receptors. A model is proposed for the molecular mechanism whereby mannose lectins are transposed from sub-plasma membrane sites to an integral membrane position as a consequence of the loss of cholesterol from the sperm membrane. |
| Health education, health promotion or drugs? Cholesterol and coronary heart disease Colquhoun, D. (1990), Med J Aust 153(5): 305-6. |
| Health education, health promotion or drugs? Cholesterol and coronary heart disease Wilson, A., S. Leeder, et al. (1990), Med J Aust 152(11): 561-3. |
| Health effect of vegetable-based diet: lettuce consumption improves cholesterol metabolism and antioxidant status in the rat Nicolle, C., N. Cardinault, et al. (2004), Clin Nutr 23(4): 605-14. Abstract: BACKGROUND & AIMS: It is often assumed that fruits and vegetables contribute to protect against degenerative pathologies such as cardiovascular diseases. Besides epidemiological observations, scientific evidences for their mechanism of action are scarce. In the present study, we investigated the mean term and post-prandial effects of lettuce ingestion on lipid metabolism and antioxidant protection in the rat. RESULTS: Feeding rats a 20% lettuce diet for 3 weeks resulted in a decrease cholesterol LDL/HDL ratio and a marked decrease of liver cholesterol levels (-41%). Concurrently, fecal total steroid excretion increased (+44%) and apparent absorption of dietary cholesterol was significantly depressed (-37%) by the lettuce diet. Lettuce diet also displayed an improvement of vitamin E/TG ratio in plasma and limited lipid peroxidation in heart as evidenced by TBARS. In post-prandial experiment, lettuce intake significantly increased both ascorbic acid and alpha-tocopherol plasma levels which contribute to improve plasma antioxidant capacity within 2 h of consumption. Other lipid-soluble antioxidants (lutein and vitamin E) may also improve the plasma antioxidant capacity. CONCLUSION: Lettuce consumption increases the total cholesterol end-products excretion and improves antioxidant status due to the richness in antioxidants (vitamins C, E and carotenoids). In our model, lettuce clearly shows a beneficial effect on lipid metabolism and on tissue oxidation. Therefore regular consumption of lettuce should contribute to improve protection against cardiovascular diseases. |
| Health locus of control and cholesterol representations. Results of the FRACTION survey Consoli, S. M. and E. Bruckert (2004), Encephale 30(4): 331-41. Abstract: The concept of the health locus of control (HLC) proved fruitful in predicting individual health behavior, in particular a person's ability to actively comply with a preventive approach. It is interesting to apply such a concept to the field of cardiovascular risk, where too many people still disregard to various degrees measures designed to control hypercholesterolemia. Now, hypercholesterolemia is recognized as a major modifiable risk factor for cardiovascular disease. OBJECTIVES: From a survey designed to explore the health beliefs concerning cholesterol and hypercholesterolemia in 1,398 subjects followed up for hypercholesterolemia by a general practitioner, we tried to determine whether the socio-demographic, clinical and cognitive characteristics of the population were related to the type of HLC of each subject (internal, chance or medical power). METHOD: All the subjects filled out a 27-item questionnaire that included one question aimed to determine their HLC type. These data were completed by a short identification sheet, encompassing various clinical data, given by the GP. A global level of dietary knowledge was computed from a question on nutritional properties of 11 foods according to the direct or indirect contribution of each food to the blood cholesterol level. RESULTS: Population consisted of 59.7% males and 40.3% females. Mean age was 57.9 +/- 11.5 years. Educational level was low (< 9 years of education) for 38% of the subjects and medium/high (10 years or more of education) for 62% of them. Hypertension was associated to hypercholesterolemia for 46.4% of the subjects, diabetes mellitus for 13.3% and coronary heart disease for 11.4% of them; 18.2% were current smokers and 34.6% past-smokers; 86.1% were already treated by lipid lowering drugs. Based on the answers to the HLC question, 42.3% of the study population can be considered as characterized by an internal HLC, 30.5% by a medical power HLC, and 27.1% by a chance HLC. An internal HLC was associated with a younger age (p < 0.008), a higher educational level (p < 0.001), less hypertension (p = 0.002), and a lower body mass index (p = 0.02). An internal HLC was also associated with several representations testifying an appropriate level of knowledge, for example: cholesterol is a basic component of the body (p = 0.001), or the presence of cholesterol in blood is normal (p = 0.04), or the desirable cholesterol level in the blood is < 2 g/l (p = 0.01) and with fewer mis-conceptions about cholesterol and hypercholesterolemia, for example: overweight individuals are more prone to have cholesterol problems (p = 0.001), or too much cholesterol may lead to cancer (p = 0.03). It was also associated with a closer identification between cholesterol and modem lifestyle (p = 0.005), with the belief that the best way of lowering cholesterol is to diet (p = 0.001) and with a lesser degree of demotivation when being aware of the role of heredity in a health problem (p = 0.001) as well as with fewer mentions of paradoxical or disappointing counter-examples of close people treated for hypercholesterolemia (p = 0.04). Finally, internal HLC subjects put forward less excuses for not to comply with dietary constraints, for example: being on diet is only possible with the spouse/family (p = 0.007), or dieting is impossible if one has an active lifestyle including eating out (p < 0.001). CONCLUSION: In spite of the very simple way used for assessing HLC in our study, without turning to a standardized multi-item inventory, these results should encourage physicians to take into account the HLC of their hypercholesterolemic patients to pass personally tailored educational messages and to motivate them to take responsibility for their own health. |
| Health policy on blood cholesterol. Time to change directions Hulley, S. B., J. M. Walsh, et al. (1992), Circulation 86(3): 1026-9. |
| Health risk appraisal and serum cholesterol nutrition education: an outcome study Powell, A. J., M. K. Lyons, et al. (1996), Mil Med 161(2): 70-4. Abstract: Records of 59 U.S. Army service members identified as at-risk for coronary heart disease were reviewed. Soldiers were divided into groups that completed and did not complete cholesterol nutrition education classes. Differences in the means of repeated cholesterol measures were compared within each group. Results showed statistically significant declines in total cholesterol, with t(35) = 2.94, p < 0.01 for the class completion group and t(22) = 2.18, p < 0.05 for the dropout group. Similar results were noted for low-density lipoprotein measures. However, cholesterol differences in the means between the two groups were not statistically significant. Results indicate that decreases in serum cholesterol may occur due to at-risk reactive behavior, but that full compliance with the current nutrition education program does not appear to further reduce cholesterol levels to any appreciable degree. |
| Health-based reference values of the Mini-Finland Health Survey: 2. Cholesterol in total serum and in different lipoprotein fractions Maatela, J., J. Marniemi, et al. (1994), Scand J Clin Lab Invest 54(1): 33-42. Abstract: The reference values for cholesterol concentrations in the whole serum and in its VLDL, LDL and HDL fractions have been produced based on the data obtained in the Mini-Finland Health Survey. The lipoprotein fractions were separated with ultracentrifugation. The aim was to obtain reference values for the apparently healthy, ambulatory population. Two health-derived criteria were used to select subjects for reference populations: those based on the literature available and those based on the recommendations published by the Committee on Reference Values of the Scandinavian Society for Clinical Chemistry and Clinical Physiology, with slight modifications. The 95% inner reference intervals of total serum cholesterol in all the subjects and in the two selection groups were 4.2-9.0, 4.2-8.4, and 4.2-8.5 mmol l-1 for men, and 4.2-9.4, 4.1-8.6, and 4.2-9.0 mmol l-1 for women, respectively. The corresponding medians were 6.3, 6.2 and 6.2 mmol l-1 in men, and 6.4, 6.0 and 6.1 mmol l-1 in women, respectively. Frequency distribution curves showed clear skewness to the right in VLDL cholesterol and slight skewness in LDL and HDL cholesterol. In women there was a clear rise in total, VLDL and LDL cholesterol after the early middle age, whereas HDL cholesterol was lower in the older age groups. In men the age dependency was not as prominent; total cholesterol levels showed lower levels in older men. Of the background lifestyle factors alcohol consumption, smoking, obesity and physical exercise had negligible associations with total, VLDL, LDL and HDL cholesterol reference intervals. |
| Healthy adults do need to know their cholesterol level. We have something to offer them! Crouse, J. R., 3rd (1996), N C Med J 57(5): 278-9. |
| Heart disease. Good cholesterol news Scott, J. (1999), Nature 400(6747): 816-7, 819. |
| Heart protection study: LDL lowering therapy and cardiovascular outcomes in patients with low cholesterol levels or diabetes Kulkarni, M. and P. D. Reaven (2002), Curr Diab Rep 2(3): 269-73. |
| Heat shock protein 60 autoimmunity and early lipid lesions in cholesterol-fed C57BL/6JBom mice during Chlamydia pneumoniae infection Erkkila, L., K. Laitinen, et al. (2004), Atherosclerosis 177(2): 321-8. Abstract: Chronic Chlamydia pneumoniae infection and autoimmunity to heat shock protein 60 (Hsp60) have both been documented to be associated with atherosclerosis. Herein, we studied the effects of C. pneumoniae infection and a diet with a low-cholesterol supplement on the development of autoantibodies to mouse Hsp60 and early lipid lesions in the aortic valve of C57BL/6JBom mice. In addition, pulmonary infection was investigated. C57BL/6JBom mice were given one to three C. pneumoniae inoculations and fed either a regular diet or a diet enriched with 0.2% cholesterol. Autoantibody responses against mouse Hsp60 developed in both diet groups when the mice were infected with C. pneumoniae and in uninfected mice fed a cholesterol-enriched diet. C. pneumoniae infections increased subendothelial foam cell accumulation in mice on a 0.2% cholesterol-enriched diet (p = 0.022), without apparent hypercholesterolemia. These in vivo data suggest that autoantibodies against mouse Hsp60 develop as a consequence of cholesterol feeding and repeated C. pneumoniae infections. Further, infectious burden increased early lipid lesions in C57BL/6JBom mice fed a cholesterol-enriched diet. |
| Heat-epimerized tea catechins rich in gallocatechin gallate and catechin gallate are more effective to inhibit cholesterol absorption than tea catechins rich in epigallocatechin gallate and epicatechin gallate Ikeda, I., M. Kobayashi, et al. (2003), J Agric Food Chem 51(25): 7303-7. Abstract: It has been known that tea catechins, (-)-epicatechin (1), (-)-epigallocatechin (2), (-)-epicatechin gallate (3), and (-)-epigallocatechin gallate (4) are epimerized to(-)-catechin (5), (-)-gallocatechin (6), (-)-catechin gallate (7), and (-)-gallocatechin gallate (8), respectively, during retort pasteurization. We previously reported that tea catechins, mainly composed of 3 and 4, effectively inhibit cholesterol absorption in rats. In this study, the effect of heat-epimerized catechins on cholesterol absorption was compared with tea catechins. Both tea catechins and heat-epimerized catechins lowered lymphatic recovery of cholesterol in rats cannulated in the thoracic duct and epimerized catechins were more effective than tea catechins. The effect of purified catechins on micellar solubility of cholesterol was examined in an in vitro study. The addition of gallate esters of catechins reduced micellar solubility of cholesterol by precipitating cholesterol from bile salt micelles. Compounds 7 and 8 were more effective to precipitate cholesterol than 3 and 4, respectively. These observations strongly suggest that heat-epimerized catechins may be more hypocholesterolemic than tea catechins. |
| Helicobacter and cholesterol gallstones: do findings in the mouse apply to man? Hofmann, A. F. (2005), Gastroenterology 128(4): 1126-9. |
| Helicobacter pylori in the etiology of cholesterol gallstones Abayli, B., S. Colakoglu, et al. (2005), J Clin Gastroenterol 39(2): 134-7. Abstract: GOALS: We aimed to investigate the presence of bacterial structures in cholesterol gallstones and particularly presence of Helicobacter spp/H. pylori in gallstones by microbiologic cultivation, histopathologic staining, and polymerase chain reaction (PCR). BACKGROUND: Many studies suggest that different mechanisms are responsible for the formation of pigmented gallstones and cholesterol gallstones. Recently, studies showed that infection could have an important role in the formation of cholesterol gallbladder stones. STUDY: We examined 77 mixed cholesterol gallstones. After cholecystectomy, gallbladder cultures were done for H. pylori and other bacterium. Gallbladder has also been examined by three histopathologic staining methods (Warthin-Starry, hematoxylin eosin, and gram staining) for Helicobacter spp. In addition, 16S rRNA-PCR amplification was performed for Helicobacter spp in gallstones. Twenty postmortem gallbladders without gallstones were investigated by the same histopathologic and PCR methods for Helicobacter spp. as a control group. RESULTS: Different bacterium were isolated from 22 gallbladder samples (12 Escherichia coli, 8 Pseudomonas, and 2 clostridium) and H. pylori was isolated in 6 gallbladder samples. Helicobacter spp was found in 7 gallstones by PCR amplification. Helicobacter-like organisms were demonstrated in 18 samples by three different histopathologic methods. Helicobacter-like organisms were also found in five samples by the same histopathologic methods (Warthin-Starry, hematoxylin-eosin, and gram staining). Only four samples were found positive for Helicobacter spp/H. pylori by all methods. CONCLUSIONS: Bacterial population including H. pylori could have a possible role in the formation of cholesterol gallstones. |