Lipoprotein profiles and serum peroxide levels of aged women consuming palmolein or oleic acid-rich sunflower oil diets.

Cuesta C, Rodenas S, Merinero MC, Rodriguez-Gil S, Sanchez-Muniz FJ.

Instituto de Nutricion y Bromatologia (CSIC-UCM), Departamento de Nutricion y Bromatologia I, Facultad de Farmacia, Universidad Complutense, Madrid, Spain.

OBJECTIVE: To investigate the hypercholesterolemic effects of a dietary exchange between 16:0 and 18:1 while 18:2 was at relatively lower level (approximately 4%) in aged women with initially high total serum cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) values and with high intakes of dietary cholesterol. DESIGN: Subjects were assigned to two consecutive 28 d periods. In the first period all subjects followed an oleic acid-rich diet in the form of oleic acid-rich sunflower oil. This was followed by a second period rich in palmitic acid in the form of palmolein. Nutrient intakes, serum lipids, lipoproteins, antioxidant vitamins, peroxides and LDL-peroxides were measured at two dietary periods. SETTING: Instituto de Nutricion y Bromatologia (CSIC), Departamento de Nutricion y Bromatologia I (Nutricion) and Seccion Departamental de Quimica Analitica, Universidad Complutense, Madrid, Spain. RESULTS: The palmolein period led to an increase in TC (P < 0.001; 17.7%) and serum apolipoprotein (Apo) B levels (P < 0.001; 18.0%). LDL-C and LDL-Apo B concentrations were higher (P < 0.001, 4.33+/-0.94 mmol/L and P < 0.01, 1.08+/-0.20 g/L, respectively) following this period than following the oleic acid-rich sunflower oil diet (3.56+/-0.85 mmol/L, 0.93+/-0.16g/L, respectively). No significant differences were observed in the TC/high density lipoprotein cholesterol (TC/HDL-C) ratio between the two dietary periods. Serum and LDL-peroxides were lower (P < 0.01, 49.5%, and P < 0.001, 69.0%, respectively) after the palmolein diet than after the oleic acid-rich sunflower oil diet. The palmolein diet significantly increased TC, LDL-C, Apo B, VLDL-ApoB, LDL-ApoB in women with TC > or = 6.21 mmol/L or with TC < 6.21 mmol/L, but the increase in Apo B, LDL-C and LDL-Apo B was greater among the women with high TC. The palmolein diet increased HDL-C in women with high or with low TC but this rise was on the borderline of statistical significance (P = 0.06) only in normocholesterolemics. Serum and LDL-peroxides tended to be higher in women with TC > 6.21 mmol/L than in women with TC < 6.21 mmol/L, but palmolein decreased serum and LDL-peroxide in hypercholesterolemics more than in the normocholesterolemics, resulting in serum and LDL-peroxide levels which theoretically are more adequate. CONCLUSIONS: Though palmolein increased LDL-C concentrations, it better protected LDL particles, mainly in women with high TC, against peroxidation than did oleic acid-rich sunflower oil.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9756125&dopt=Abstract cholesterol




The water-soluble extract of chicory influences serum and liver lipid concentrations, cecal short-chain fatty acid concentrations and fecal lipid excretion in rats.

Kim M, Shin HK.

Division of Toxic Metals, Korea Food and Drug Administration, 5 Nokbun-dong Seoul, 122-704, Korea.

Sprague-Dawley rats (n = 32) were fed diets without fiber (control) or containing 1 or 5% chicory extract or 5% inulin for 4 wk; 0.2% cholesterol was added to all diets. Rats fed chicory extract and inulin diets had significantly higher serum high density lipoprotein (HDL) cholesterol and generally lower low density lipoprotein (LDL) cholesterol concentrations, thus significantly greater ratios of HDL/LDL cholesterol compared with the controls (P < 0.05). The serum apolipoprotein B/apolipoprotein A-1 ratio was significantly lower in rats fed diets containing chicory extract or inulin than that in rats fed fiber-free diets, due to significant reductions in apolipoprotein B concentration (P < 0.05). Greater liver lipid and triglyceride concentrations were observed in rats fed chicory extract or inulin diets compared with the controls (P < 0.05). However, liver phospholipid and cholesterol concentrations were not significantly different among groups (P > 0.05). Addition of 5% inulin to the diet resulted in greater cecal weight, whereas both 5% chicory extract and 5% inulin resulted in greater cecal propionic acid concentration compared with the controls (P < 0.05). Rats fed chicory extract and inulin had significantly greater fecal lipid, cholesterol and bile acid excretions than those fed fiber-free diets (P < 0.05). The results of this study suggest that the improved lipid metabolism observed in rats fed chicory extract (mainly inulin component) may be caused by an alteration in the absorption and/or synthesis of cholesterol, which might result from the changes in cecal fermentation, and by an increase in the fecal excretion of lipid, cholesterol and bile acid.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9772143&dopt=Abstract cholesterol




Maternal and cord plasma lipid and lipoprotein concentrations in women with and without gestational diabetes mellitus. Predictors of birth weight?

Couch SC, Philipson EH, Bendel RB, Wijendran V, Lammi-Keefe CJ.

Department of Nutritional Sciences, University of Connecticut, Storrs 06269, USA.

OBJECTIVE: To describe lipid and lipoprotein perturbations in gestational diabetes mellitus (GDM) and to examine the potential consequences--e.g, increased birth weight and increased placental lipid transfer. STUDY DESIGN: Maternal and cord free fatty acids (FFAs) and total, very low density lipoprotein (VLDL), low density lipoprotein (LDL), high density lipoprotein (HDL) (and maternal HDL2 and HDL3), triglyceride (TG), and cholesterol and dietary intake were determined for women with diet-treated GDM and for healthy pregnant women with normal glucose tolerance. RESULTS: Women with GDM had higher hemoglobin A1c than controls, while body weight gain was significantly lower for women with GDM as compared to controls. Plasma and lipoprotein TG concentrations were greater for women with GDM, and although plasma FFAs were higher in women with GDM versus controls, the difference was not significant. No differences were observed between groups with respect to maternal plasma or lipoprotein cholesterol. Cord plasma and lipoprotein lipids were similar between groups; with the exception of VLDL + LDL TG, which was lower in women with GDM. In controls, there were significant correlations between maternal plasma TG and cord FFAs; maternal HDL2 cholesterol and cord plasma cholesterol; and maternal plasma TG, maternal HDL2 cholesterol, cord FFAs, and infant birth weight. In GDM, maternal plasma cholesterol and cord VLDL + LDL cholesterol correlated. There were no significant correlations between maternal or cord lipids and infant birth weight in women with GDM. CONCLUSION: Hypertriglyceridemia, rather than hypercholesterolemia, is a feature of GDM. However, elevations in maternal plasma and lipoprotein TGs in women with GDM were not related to fetal lipid concentrations or infant birth weight.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9777622&dopt=Abstract cholesterol




Vitamin E supplementation attenuates myointimal proliferation of the abdominal aorta after balloon injury in diet-induced hypercholesterolemic rabbits.

Chen MF, Hsu HC, Liau CS, Lee YT.

Department of Internal Medicine (Cardiology), National Taiwan University Medical Center, Taipei. mfchen .ha.mc.ntu.edu.tw

The effects of vitamin E supplementation in a dose of 450 mg/1000 g chow on the myointimal proliferation of the abdominal aorta after balloon injury were studied in 4 groups of rabbits (24 each). The animals were fed regular diet, regular diet plus vitamin E, 1% cholesterol-enriched diet, and 1% cholesterol-enriched diet plus vitamin E. Each animal underwent a balloon injury of the abdominal aorta and left common iliac artery after 2 weeks of feeding. The animals remained on their respective diets thereafter. In 8 balloon-injured and 8 sham-operated animals of each group, the abdominal aortas were harvested 3 days after the procedure for the analysis of prostacyclin and thromboxane A2 synthesis, thiobarbituric acid reactive substances (TBARS) levels, enzyme activities of glutathione reductase (GR) and glutathione peroxidase (GP) as well as reduced (GSH) and oxidized (GSSG) glutathione levels, 3H-thymidine uptake, cholesterol as well as vitamin E contents. In the other 8 balloon-injured rabbits of each group, the tissue was harvested 3 weeks later for the morphometric study. In dependent of high cholesterol feeding, the vitamin E-treated rabbits had lower aortic production of thromboxane B2, higher 6-keto-PGF1 alpha and higher 6-keto-PGF1 alpha/thromboxane B2 ratios in both procedures. The aortic TBARS levels of the rabbits treated high cholesterol alone were significantly higher than the other three groups in both procedures. Balloon injury had a trend to increase TBARS levels and had significantly higher 3H-thymidine uptake (each p < 0.001) than sham operation in each group. Vitamin E supplement to high cholesterol diet or regular chow reduced aortic TBARS levels (p < 0.005 and 0.01, respectively) and 3H-thymidine uptake (p < 0.05 and 0.01, respectively), as well as attenuated myointimal proliferation of the abdominal aorta and left common iliac artery after balloon injury; but only supplement to high cholesterol diet reached statistical significances (both p < 0.05 compared to rabbits fed high cholesterol alone). These results suggest that vitamin E supplement changes prostanoid metabolism to a favorable pattern and reduces lipid peroxidation of the abdominal aortic wall, thus attenuates myointimal proliferation after balloon injury; these presentations are particularly obvious in diet-induced hypercholesterolemic rabbits.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9777654&dopt=Abstract cholesterol




Decreased blood oxygen diffusion in hypercholesterolemia.

Menchaca HJ, Michalek VN, Rohde TD, O'Dea TJ, Buchwald H.

Department of Surgery, University of Minnesota, Minneapolis, USA.

BACKGROUND: Improvement of angina pectoris symptoms after cholesterol lowering has raised questions as to the underlying mechanisms. METHODS: Rabbit experiment: We compared arterial blood samples from New Zealand White cholesterol-supplemented rabbits (n = 6) with nonsupplemented rabbit samples (n = 4) in a closed-loop circulation diffusion system. The pH and partial pressures of oxygen (pO2) and carbon dioxide (pCO2) were measured continuously. The samples were first oxygen (O2) saturated (pO2, 160 mm Hg; pCO2, 4 mm Hg) and then desaturated in 100% nitrogen. Cholesterol levels were determined in whole blood, plasma (P Chol), red blood cells (RBCs), and RBC membranes. Human experiment: We exposed quadruple desaturated venous blood samples (n = 4) with P Chol levels of 87 to 400 mg/dL in a gas exchanger to capillary gas conditions (pO2, 23 mm Hg; pCO2, 46 mm Hg). After 15 minutes we performed blood gas analyses and compared our results to baseline values. RESULTS: In the rabbit experiment the cholesterol-supplemented group as compared to the control group showed higher plasma pO2 levels during the saturation phase and lower plasma pO2 levels during the desaturation phase. It also had a markedly increased RBC membrane cholesterol content: 121 +/- 3 (standard error of the mean [SEM]) mg/dL versus 22 +/- 1.7 mg/dL in the control group (P < .05). This barrier to RBC membrane O2 diffusion caused delayed O2 entry into the RBCs during saturation, with a higher plasma pO2, and delayed O2 release from the RBCs during desaturation, with a lower plasma pO2. In the human experiment the P Chol level was inversely correlated with the percentage change of O2 content in milliliters of O2 per deciliter of blood (P < .05). CONCLUSIONS: Increased RBC membrane cholesterol in hypercholesterolemia appears to decrease the transmembrane O2 diffusion rate.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9780990&dopt=Abstract cholesterol




Effect of pregnancy and lactation on lipoprotein and cholesterol metabolism in the rat.

Smith JL, Lear SR, Forte TM, Ko W, Massimi M, Erickson SK.

Department of Medicine, University of California, San Francisco, and Department of Veterans Affairs Medical Center, San Francisco, CA 94121, USA.

Origins of hyperlipidemia and cholestasis that occur during pregnancy were investigated by examining expression of key elements related to plasma and hepatic cholesterol metabolism during pregnancy, lactation, and post-lactation in the rat model. Among major findings were: during pregnancy, the activities of hepatic 3-hydroxy-3-methylglutaryl coenzyme A reductase, acyl coenzyme A:cholesterol acyltransferase, acyl coenzyme A:diacylglycerol acyltransferase, cholesterol 7alpha-hydroxylase, cholesterol ester hydrolases, low density lipoprotein receptors, LRP, and mdr2 were significantly lower or similar to non-pregnant controls while SR-B1 was elevated. Once lactation began, reductase, cholesterol acyltransferase, 7alpha-hydroxylase activities, low density lipoprotein receptors, and mdr2 increased while SR-B1 decreased. In later stages of lactation most hepatic elements returned to near control levels. Plasma cholesterol levels were higher than control at birth and during lactation with increase in LDL-size particles. By 24 h post-lactation, plasma triglycerides were 3.7-fold higher while cholesterol remained unchanged. Very large lipoproteins were present while LDL-size particles were now absent. Hepatic cholesterol acyltransferase had decreased to 27% of control while diacylglycerol acyltransferase increased 3-fold and low density lipoprotein receptors doubled. Most elements were normalized 3 weeks after weaning except for LRP and low density lipoprotein receptors which were elevated.These studies provide an integrated picture of expression of key elements of hepatic and plasma cholesterol metabolism during pregnancy and lactation and advance understanding of hyperlipidemia and cholestasis during these states.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9799810&dopt=Abstract cholesterol




Dietary pectin with high viscosity lowers plasma and liver cholesterol concentration and plasma cholesteryl ester transfer protein activity in hamsters.

Terpstra AH, Lapre JA, de Vries HT, Beynen AC.

Department of Laboratory Animal Science, Faculty of Veterinary Medicine, Utrecht University, 3584 CM Utrecht, The Netherlands.

We fed semipurified diets containing pectin with either a high or low in vitro viscosity at a level of 3 g/100 g air-dried diet to hamsters for 8 wk. A control group was fed cellulose and a positive control group was fed psyllium. The pectins used were a calcium-sensitive pectin (CS-pectin) that has a high viscosity and a noncalcium-sensitive pectin (NCS-pectin) that has a low viscosity. In the presence of calcium, CS-pectin has a more than 80-fold higher viscosity than NCS-pectin which offered the opportunity to investigate the possible role of viscosity in the hypolipidemic properties of pectin. The hamsters fed CS-pectin or psyllium had considerably lower plasma cholesterol concentrations (3.69 +/- 0.44 and 4.21 +/- 0.45 mmol/L, respectively, mean +/- SD, n = 14) than those fed NCS-pectin (5.03 +/- 1.15 mmol/L) or cellulose (5.72 +/- 1. 04 mmol/L). Differences in total plasma cholesterol were reflected in both high density lipoprotein and very low density lipoprotein cholesterol. There was no effect of fiber on low density lipoprotein cholesterol levels. Liver cholesterol concentrations paralleled the plasma cholesterol levels and were 9.91 +/- 2.48 micromol/g of liver for the CS-pectin group, 15.03 +/- 5.75 for the psyllium group, 17. 69 +/- 10.66 for the NCS-pectin group, and 25.57 +/- 9.23 for the cellulose group. Fecal bile acid and neutral steroid excretion tended to be higher in the hamsters fed CS-pectin than in their counterparts fed NCS-pectin. The hamsters fed psyllium had significantly greater fecal excretions of bile acids than the hamsters fed cellulose, CS-pectin or NCS-pectin, whereas the excretion of fecal neutral sterols tended to be lower. Plasma cholesteryl ester transfer protein activity was significantly lower in the hamsters fed CS-pectin than in those fed NCS-pectin. The results of this study suggest that the viscosity of pectins may determine their cholesterolemic effect.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9808647&dopt=Abstract cholesterol




Lipid and lipoprotein profiles in children with familial hypercholesterolaemia: effects of therapy.

Hennermann JB, Herwig J, Marz W, Asskali F, Bohles HJ.

Children's Hospital, Johann Wolfgang Goethe, University, Frankfurt/Main, Germany. jhennerm charite.de

In 71 children with familial hypercholesterolaemia the effect of dietary and/or medical treatment was evaluated. Initial total cholesterol and low density lipoprotein (LDL)-cholesterol levels were significantly lower in children who were consecutively treated by diet (Step-One-Diet) than in those who received additional medication. By dietary treatment, the median total cholesterol level (236.5 mg/dl; range 210-510 mg/dl) was reduced by 7.4% and the median LDL-cholesterol level (162 mg/dl; range 126-423 mg/dl) by 9.9%. By dietary and medical therapy, the median total cholesterol level (330 mg/dl; range 270-424 mg/dl) was reduced by 29.7% and the median LDL-cholesterol level (263 mg/dl; 192-333 mg/dl) by 25.9%. High density lipoprotein (HDL)-cholesterol and HDL 3 remained unchanged. HDL 2 showed a significant decrease of 15.6% up to 27 mg/dl (13-42 mg/dl) on medical treatment. Apolipoprotein A I levels did not change during therapy. Initial apolipoprotein B levels were significantly higher in children who were treated by diet and medication and were reduced by 28.9% by combined therapy. In 28 patients (39.4%) an excess of lipoprotein (a) was detected. Regarding the apolipoprotein E phenotype, 32.2% of the patients carried the risk gene epsilon4 in a hetero- or homozygous form. CONCLUSION: Early dietary and/or medical treatment in hypercholesterolaemic children significantly ameliorates the lipoprotein status. The pretherapy lipoprotein status seems to prognosticate the effectiveness of therapy.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9835436&dopt=Abstract cholesterol




Cholesterolemia in colorectal cancer.

Forones NM, Falcao JB, Mattos D, Barone B.

Clinical Gastroenterology, Oncology Division, Universidade Federal de Sao Paulo (UNIFESP-Escola Paulista de Medicina), SP, Brazil. nora gastro.epm.br

BACKGROUND/AIMS: Colorectal cancer incidence is higher in developed countries. High fat intake is one of the risk factors. However, many studies observed lower cholesterol serum levels on diagnosis of colorectal cancer. The aim of this assay was to study the serum cholesterol levels in patients with colorectal cancer and compare these values with individuals of the same age and sex. METHODOLOGY: Cholesterol serum levels of 85 patients with colorectal cancer were determined. Each of the patients with colorectal cancer were matched with an individual without cancer of the same age and sex. Total cholesterol concentrations were determined using an enzymatic colorimetric method. RESULTS: The mean serum of cholesterol was 183.4 for the colorectal group and 209.7 for the control group. This difference was statistically significant. This difference was more evident in patients with colon cancer and older than 60 years of age. There was no difference between the different Dukes' stage. CONCLUSIONS: Our study suggest an association between low blood cholesterol and colorectal cancer. We believe that the lower level of cholesterol observed in these patients is a consequence between the difference of colorectal carcinogenesis.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9840100&dopt=Abstract cholesterol