Plasma High-density Lipoprotein Cholesterol Concentrations Research Articles

Isocaloric substitution of plant sterol-enriched fat spread for carbohydrate-rich foods in a low-fat, fibre-rich diet decreases plasma low-density lipoprotein cholesterol and increases high-density lipoprotein concentrations

The aim of the study was to determine the effects on plasma cholesterol of replacing a plant sterol-enriched fat spread with carbohydrate-rich foods relative to a diet high in saturated fat. Twenty-nine men and women, from the general community, with mean age (SD) 48 (14)y, body mass index 29.0 (6.2)kg/m(2), and plasma total cholesterol concentration 6.48 (0.97)mmol/L completed the randomised, crossover dietary intervention. There were three diets: New Zealand diet (NZ diet) high in total (34%kJ) and saturated (15%kJ) fat, a cholesterol-lowering fibre-rich diet reduced in total (30%kJ) and saturated fat (8%kJ) but including a plant sterol spread (PS diet), and the same cholesterol-lowering diet with the plant sterol spread isocalorically replaced with carbohydrate (CHO diet); total fat, 26%kJ; saturated fat 7%kJ. All foods were provided and each diet was followed for four weeks. Mean (SD) plasma low-density lipoprotein cholesterol concentration declined from 4.68 (0.91)mmol/L on the high saturated fat diet to 4.12 (0.83)mmol/L (P<0.001) on the carbohydrate diet and 3.76 (0.84)mmol/L (P<0.001) on the plant sterol diet. The 20% decrease on the plant sterol diet was significantly greater (P<0.001) than the 12% decrease on the carbohydrate diet. Relative to the NZ diet, mean (95% CI) plasma high-density lipoprotein cholesterol concentration changed by -0.11 (-0.16, -0.06)mmol/L on the CHO diet but was not different at the end of the PS diet, -0.03 (-0.09, 0.02). Including a plant sterol-enriched fat spread in a cholesterol-lowering diet produces a more favourable plasma lipid profile than the same diet made lower in total and saturated fat by replacing the spread with carbohydrate-rich foods.

Family history, diabetes and extension of coronary atherosclerosis are strong predictors of adverse events after PTCA: A one-year follow-up study

In this study we addressed some open questions in patients with coronary artery disease (CAD). First, we analysed which of the traditional risk factors was associated with the spreading of coronary stenosis and second, we aimed to identify if any variable was predictive of post-percutaneous transluminal coronary angioplasty (PTCA) clinical events. We collected a consecutive series of patients with CAD (n=301) and in the subgroup of patients undergoing PTCA (n=135) we performed a prospective one-year follow-up study recording cardiovascular morbidity and total mortality. According to the extension of coronary atherosclerosis, we found a significant relationship with the prevalence of diabetes in men and with plasma HDL-cholesterol concentrations in women. The follow-up was completed in 95% of patients; we did not document any death whereas clinical events were registered in 16% of patients. At univariate analysis, we found that patients with clinical events had a higher prevalence of family history of CAD (43% vs 14%, p<0.005), diabetes (52% vs 21%, p<0.005) and multivessel disease (52% vs 35%, p<0.05). Multivariate analysis (logistic regression) confirmed that family history of CAD (OR 4.6, 95% CI 1.7-12.8, p<0.005), diabetes (OR 4.0, 95% CI 1.5-10.6, p<0.01) and multivessel disease (OR 2.8, 95% CI 1.1-7.4, p<0.05) were the only variables predictive of clinical events. In this study, factors associated with the spreading of coronary stenosis were different according to the gender. Moreover, the presence of diabetes and multivessel disease had a negative impact on the long-term prognosis of patients undergoing PTCA. In addition, the family history of CAD represented in our study a strong predictor of clinical events. We suggest that in the management of post-PTCA patients, the role of individual baseline clinical characteristics must be taken into account and that subjects with a family history of premature CAD, diabetes and a wide extension of coronary disease represent those with the highest risk.

Interactions between the −514C→T polymorphism of the hepatic lipase gene and lifestyle factors in relation to HDL concentrations among US diabetic men

Low plasma HDL-cholesterol concentrations are a hallmark of diabetic dyslipidemia. A common polymorphism (-514C-->T) of the hepatic lipase gene (LIPC), which accounts for up to 30% of the variation in hepatic lipase activity, has been associated with low hepatic lipase activity and high HDL-cholesterol concentrations. We examined the association between this polymorphism and plasma HDL-cholesterol concentrations and evaluated whether this association was modified by adiposity and dietary fat intake. We followed men aged 40-75 y who participated in the Health Professionals Follow-Up Study in 1986. Among 18 159 men who returned blood samples by 1994, 780 had confirmed type 2 diabetes at blood drawing or during follow-up to 1998 and were free of cardiovascular disease at blood drawing. After adjustment for age, smoking, alcohol consumption, fasting status, glycated hemoglobin concentration, physical activity, and body mass index, HDL-cholesterol concentrations were significantly higher in men with the C/T or T/T genotype than in those with the C/C genotype (adjusted x: 40.9 and 38.8 mg/dL, respectively; P = 0.01). We observed significant LIPC -514 polymorphism x body mass index and LIPC -514 polymorphism x saturated fat intake interactions for HDL-cholesterol concentrations (P = 0.003 for both). The T allele was associated with higher HDL-cholesterol concentrations only in men who were not overweight or who had higher saturated fat intake. Our study suggests that the effects of -514C-->T of the LIPC gene on HDL concentrations were modified by saturated fat intake and obesity.

A dietary pattern protective against type 2 diabetes in the European Prospective Investigation into Cancer and Nutrition (EPIC)—Potsdam Study cohort

The aim of this study was to identify a dietary pattern associated with diabetes-related biomarkers and to investigate whether this pattern is associated with the incidence of type 2 diabetes. A nested case-control study of 192 cases of incident type 2 diabetes and 382 control subjects matched for sex and age was conducted. All subjects were participants in the population-based European Prospective Investigation into Cancer and Nutrition (EPIC)-Potsdam Study. Dietary pattern score was derived using intake data on 48 food groups as exposure variables and the biomarkers HbA1c, HDL cholesterol, C-reactive protein and adiponectin as response variables in reduced rank regression. The association of the score with diabetes risk was estimated by conditional logistic regression analysis. A high score for the identified dietary pattern was characterised by a high intake of fresh fruit and a low intake of high-caloric soft drinks, beer, red meat, poultry, processed meat, legumes and bread (excluding wholegrain bread). Subjects with high scores had high plasma concentrations of HDL cholesterol and adiponectin and low plasma concentrations of HbA1c and C-reactive protein. After multivariate adjustment, the odds ratios for type 2 diabetes across increasing quintiles of the dietary pattern score were 1.0, 0.59, 0.51, 0.26 and 0.27, respectively (p = 0.0006 for trend). A high score for the identified dietary pattern is associated with a more favourable biomarker profile and a substantially reduced incidence of type 2 diabetes.

Effects of peroxisome proliferator-activated receptor α/δ agonists on HDL-cholesterol in vervet monkeys

The objective of this study was to demonstrate the efficacy of a novel peroxisome proliferator-activated receptor (PPAR) agonist and known PPARalpha and PPARdelta agonists to increase HDL-cholesterol (HDL-C) in the St. Kitts vervet, a nonhuman primate model of atherosclerosis. Four groups (n = 6) were studied and each group was assigned one of the following "treatments": a) vehicle only (vehicle); b) the PPARdelta selective agonist GW501516 (GW); c) the PPARalpha/delta agonist T913659 (T659); and d) the PPARalpha agonist TriCor (fenofibrate). No statistically significant changes were seen in body weight, total plasma cholesterol, plasma triglycerides, VLDL-C, LDL-C, or apolipoprotein B (apoB) concentrations. Each of the PPARalpha and PPARdelta agonists investigated in this study increased plasma HDL-C, apoA-I, and apoA-II concentrations and increased HDL particle size in St. Kitts vervets. The maximum percentage increase in HDL-C from baseline for each group was as follows: vehicle, 5%; GW, 43%; T659, 43%; and fenofibrate, 20%. Treatment with GW and T659 resulted in an increase in medium-sized HDL particles, whereas fenofibrate showed increases in large HDL particles. These data provide additional evidence that PPARalpha and PPARdelta agonists (both mixed and selective) have beneficial effects on HDL-C in these experimental primates.

TaqIB polymorphism in CETP gene: the influence on incidence of cardiovascular disease in statin-treated patients with familial hypercholesterolemia

The effects of TaqI restriction fragment length polymorphism of the CETP gene on the occurrence of cardiovascular disease (CVD) events were investigated in patients with familial hypercholesterolemia (FH). A total of 300 FH patients, of which 116 (39%) had CVD at the start of the study, were treated with statins during a mean period of 8.5 years. The distribution of Taq1B genotypes was 31% B1B1, 49% B1B2, and 20% B2B2. No differences were found at baseline between the three genotypes, except for an association of the B1 allele with lower high-density lipoprotein (HDL)-cholesterol levels (P=0.003). All patients were put on statins within 6-8 weeks after the first visit; about 60% received simvastatin (20-40 mg daily) and 40% either pravastatin (40 mg daily) or atorvastatin (20-40 mg daily). The different statin treatments were similar for all groups. The mean change of plasma HDL-cholesterol, low-density lipoprotein-cholesterol, and triglyceride concentration during statin therapy was similar for the three genotypes. During follow-up, new CVD events were recorded in 22 (37%) of the B2B2 patients (n=59) and in 67 (28%) of B1 allele carriers (n=241) (P=0.36). The relative risk for CVD events, after adjustment for age, gender, and CVD at intake, was 1.8 (CI: 1.1-3.0) for B2B2 carriers compared to B1 allele carriers. The Taq1B polymorphism is a significant predictor of future CVD events in statin-treated patients with FH. In spite of similar improvement of the lipoprotein profile during statin therapy, our FH patients with the B2B2 genotype may have a higher CVD risk in comparison with the B1 allele carriers.

Apolipoprotein L-I is positively associated with hyperglycemia and plasma triglycerides in CAD patients with low HDL

Apolipoprotein L-I (apoL-I) is present on a subset of HDL particles and is positively correlated with plasma triglycerides (TGs). We measured plasma apoL-I levels in coronary artery disease (CAD) subjects with low HDL who were enrolled in an angiographic CAD prevention trial. At baseline, apoL-I levels (n = 136; range, 2.2-64.1 mug/ml) were right skewed with a large degree of variability. Multivariate analysis for biological determinants of apoL-I revealed that the log of VLDL-TG (+0.17; P < 0.05) and hyperglycemia (HG; +0.26; P < 0.005) independently predicted apoL-I level. Hyperglycemic patients (n = 24) had mean apoL-I levels >50% higher than normoglycemic subjects (n = 112; 13.2 vs. 8.3 mug/ml, respectively; P < 0.001). No relationship between apoL-I level and change in CAD was found (r = 0.06, P = 0.49). Simvastatin-niacin therapy did not alter apoL-I levels (n = 34; P = 0.27), whereas antioxidant vitamins alone increased apoL-I by >50% (n = 36; P < 0.01). Genotyping of a known apoL-I polymorphism (Lys166Glu) did not independently account for any of the variability in apoL-I levels. In conclusion, we found TG and HG to be the strongest predictors of apoL-I within a dyslipidemic CAD population. These data provide further characterization of the novel HDL-associated apoL-I.

Energy Expenditure from Physical Activity and the Metabolic Risk Profile at Menopause

A sedentary lifestyle and visceral obesity are important risk factors for Type 2 diabetes and the development of cardiovascular disease, two conditions that are prevalent in women after menopause. The aim of this study was to assess the relationship between daily energy expenditure from moderate to intense physical activity and several metabolic parameters in postmenopausal women not receiving hormone therapy (HT) and to verify whether these associations are independent of the accumulation of visceral adipose tissue (AT). Daily energy expenditure and frequency of participation in physical activity (kcal.kg(-1).15 min(-1)) were measured from a 3-d activity diary in 118 postmenopausal women (56 +/- 4 yr; 29 +/- 6 kg.m(-2)). Daily activities for each 15-min period during 24 h were categorized according to their intensity on a 1-9 scale. Category 1 indicated very low energy expenditure such as sleeping, and category 9 indicated very high energy expenditure such as running. Energy expenditure corresponding to categories 6-9 (EE6-9) was examined in relation to the metabolic risk profile. EE6-9 was negatively and significantly associated with body mass index (BMI) (r = -0.22, P < 0.05) and visceral AT accumulation (r = -0.18, P < 0.05). Partial correlation analyses adjusted for visceral AT showed that EE6-9 was significantly associated with systolic blood pressure (r = -0.22, P < 0.05), plasma concentrations of HDL-cholesterol (chol) (r = 0.23, P < 0.05), HDL2-chol (r = 0.22, P < 0.05), fasting glucose (r = -0.24, P < 0.05), and fasting C-peptide (r = -0.24, P = or <0.05). EE6-9 was also associated with insulin sensitivity as measured by the hyperinsulinemic-euglycemic clamp (r = 0.27, P < 0.01). Higher engagement in physical activity (EE6-9) is associated with a lower BMI and visceral AT accumulation and with a healthier metabolic profile in postmenopausal women. Furthermore, the associations between EE6-9 and some metabolic parameters appear to be independent of visceral AT accumulation.

Vitamin E supplementation alters HDL-cholesterol concentration and paraoxonase activity in rabbits fed high-cholesterol diet: Comparison with probucol

Vitamin E and probucol are well-known antioxidants that prevent cells from the oxidative stress, which is a risk factor of atherosclerosis. Male rabbits were fed either 0.03% vitamin E or 0.05% probucol in a 0.5% high-cholesterol (HC) diet for 8 weeks. Vitamin E and probucol significantly suppressed an increase in plasma total-cholesterol (total-C) and low-density lipoprotein cholesterol compared to HC-control group. However, plasma high-density lipoprotein-cholesterol (HDL-C) and HDL-C/total-C ratio levels and plasma paraoxonase activity were only significantly higher in vitamin E group after 8 weeks. Hepatic ACAT activity was significantly lower in both vitamin E and probucol groups than in HC-control group, while HMG-CoA reductase activity was the highest only in the probucol group. Total fecal sterol content was significantly higher in probucol and vitamin E groups than in the two control groups. Some atherogenic signs were discovered in the aortic fatty streak of HC-control group, yet not in other groups. Hepatic mRNA expressions of apo B-100 and apo C-III were significantly lower in probucol group than in other groups. Vitamin E supplementation was found to alter the plasma HDL-C-related factors; meanwhile, probucol supplementation was very effective in enhancing cholesterol metabolism, except for a negative effect that reduced plasma HDL-C concentration.

Genetics of Variation in HDL Cholesterol in Humans and Mice

Plasma high-density lipoprotein cholesterol (HDL-C) concentrations are genetically determined to a great extent, and quantitative trait locus (QTL) analysis has been used to identify chromosomal regions containing genes regulating HDL-C levels. We discuss new genes found to participate in HDL metabolism. We also summarize 37 mouse and 30 human QTLs for plasma HDL-C levels, finding that all but three of the mouse QTLs have been confirmed by a second cross or a homologous human QTL, that the mouse QTL map is almost saturated because 92% of recently reported QTLs are repeats of those already found, and that 28 of the 30 human QTLs are located in regions homologous to mouse QTLs. This high degree of concordance between mouse and human QTLs suggests that the underlying genes may be the same. Strategies to more rapidly identify genes underlying mouse and human QTLs for HDL-C include focusing on the mouse and using mouse-human homologies, combining crosses, and haplotyping to narrow the region. Sequence analysis and expression studies can distinguish candidate genes consistent across multiple mouse crosses, and testing the candidate genes in human association studies can provide additional evidence for the candidacy of a gene. Together these strategies can accelerate the pace of finding genes that regulate HDL.

Soy intake and blood cholesterol concentrations: a cross-sectional study of 1033 pre- and postmenopausal women in the Oxford arm of the European Prospective Investigation into Cancer and Nutrition

Clinical trials have suggested that the intake of soy protein reduces blood cholesterol. Few studies have explored this relation in subjects who consume soy as part of their regular diet. In this study, we investigated whether blood cholesterol concentrations are related to the intake of soyfoods in a cohort comprising subjects with a wide variation in soy intake. This cross-sectional study included 1033 pre- and postmenopausal women selected from the Oxford arm of the European Prospective Investigation into Cancer and Nutrition. The sample included 361 nonvegetarians, 570 vegetarians, and 102 vegans. Their dietary intake was assessed by using a food-frequency questionnaire. Anthropometric data, medical history, and lifestyle information were obtained with the use of a questionnaire, blood samples were obtained, and plasma total, LDL-, and HDL-cholesterol concentrations were measured. Soy-protein intake was inversely associated with total and LDL-cholesterol concentrations and with the ratio of total to HDL cholesterol but not with HDL-cholesterol concentrations. Mean plasma LDL-cholesterol concentrations in women with a soy-protein intake >/=6 g/d was 12.4% lower than that in women who consumed <0.5 g/d (P < 0.001). Moderate intakes of soyfoods as part of a regular diet are associated with favorable blood cholesterol concentrations.

Effects of a low-fat diet compared with those of a high-monounsaturated fat diet on body weight, plasma lipids and lipoproteins, and glycemic control in type 2 diabetes

An important therapeutic goal for patients with type 2 diabetes is weight loss, which improves metabolic abnormalities. Ad libitum low-fat diets cause weight loss in nondiabetic populations. Compared with diets higher in monounsaturated fat, however, eucaloric low-fat diets may increase plasma triacylglycerol concentrations and worsen glycemic control in persons with type 2 diabetes. We investigated whether, in type 2 diabetes patients, an ad libitum low-fat diet would cause greater weight loss than would a high-monounsaturated fat diet and would do this without increasing plasma triacylglycerol concentrations or worsening glycemic control. Eleven patients with type 2 diabetes were randomly assigned to receive an ad libitum low-fat, high-carbohydrate diet or a high-monounsaturated fat diet, each for 6 wk. The diets offered contained 125% of the estimated energy requirement to allow self-selection of food quantity. The response variables were body weight; fasting plasma lipid, lipoprotein, glucose, glycated hemoglobin A(1c), and fructosamine concentrations; insulin sensitivity; and glucose disposal. Body weight decreased significantly (1.53 kg; P < 0.001) only with the low-fat diet. Plasma total, LDL-, and HDL-cholesterol concentrations tended to decrease during both diets. There were no interaction effects between diet and the lipid profile response over time. Plasma triacylglycerol concentrations, glycemic control, and insulin sensitivity did not differ significantly between the 2 diets. Contrary to expectations, the ad libitum, low-fat, high-fiber diet promoted weight loss in patients with type 2 diabetes without causing unfavorable alterations in plasma lipids or glycemic control.

The -514 C->T hepatic lipase promoter region polymorphism and plasma lipids: a meta-analysis.

Investigations of the -514 C-->T single nucleotide polymorphism (SNP) in the hepatic lipase (HL) gene promoter region (LIPC) have yielded contradictory results regarding its association with changes in plasma lipids. The current study is a meta-analysis of 25 publications on this SNP, comprising over 24,000 individuals, and its relationship with total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol (HDL), triglycerides, and HL activity. Significant decreases were observed in HL activity for both the CT and TT genotypes compared with the CC genotype [weighted mean difference (WMD), -5.83 mmol/liter.h (95% confidence interval, -8.48, -3.17) and -11.05 mmol/liter.h (95% confidence interval, -14.74, -7.36), respectively]. Moreover, significant increases in HDL were found; the CT to CC comparison showed an increase in WMD of 0.04 mmol/liter (95% confidence interval, 0.02, 0.05) mmol/liter, and the increase in the TT vs. CC difference was WMD of 0.09 mmol/liter (95% confidence interval, 0.07, 0.12). These changes appear to be stepwise, implying an allele dosage effect. All P values for these associations were less than 0.001. This meta-analysis demonstrates the importance of the -514C-->T SNP in determining HL activity and plasma HDL concentration and helps quantify the role that hepatic lipase plays in the metabolism of HDL.

Human apoA-I/C-III/A-IV gene cluster transgenic rabbits: effects of a high-cholesterol diet

We have generated transgenic rabbits that express the entire human apoA-I/C-III/A-IV gene cluster. As in humans, h-apoA-I and h-apoC-III were expressed in liver and intestine, whereas h-apoA-IV mRNA was detected in intestine only. Transgenic rabbits had significantly higher plasma total cholesterol, HDL-cholesterol and total phospholipid concentrations than non-transgenic littermates. In contrast to similar transgenic mice previously generated, which have gross hypertriglyceridemia, triglyceride concentrations were only moderately raised in transgenic rabbits. Plasma and HDL from transgenic rabbits were more effective than those from controls in promoting cholesterol efflux from cultured hepatoma cells. They had lower LCAT, lower CETP and higher PLTP activities than non-transgenic littermates. Cholesterol-feeding produced major increases in plasma lipids. The qualitative response to the diet was not modified by cluster expression. Human apoA-I concentration was halved by cholesterol-feeding, whereas h-apoC-III and h-apoA-IV concentrations were not significantly altered. Cholesterol efflux from hepatoma cells to plasma and HDL was not altered by the diet. Since lipoprotein metabolism of rabbits closely resembles that of humans, human apoA-I/C-III/A-IV transgenic rabbits may provide a reliable model for studies of the transcriptional regulation of the cluster, and for evaluating the effects of different agents on the expression of the three genes.

Consistently high plasma high-density lipoprotein-cholesterol levels in children in Spain, a country with low cardiovascular mortality

Coronary heart disease (CHD) mortality is relatively low in Spain compared with other developed countries and has remained low despite an apparent increase in mean plasma cholesterol concentration in adults over the last several years. It is accepted that pathologic processes related to arteriosclerosis development begin in childhood and seem to be related to the presence of cardiovascular risk factors at this age. High-density lipoprotein-cholesterol (HDL-C) levels in children have been inversely correlated with the incidence of coronary heart disease in the different countries studied. Childhood plasma lipoprotein profile might contribute to the low coronary heart disease mortality in Spain. Thus, we analyzed data on lipid levels over time in schoolchildren in Spain in the last decade. Plasma lipid levels were analyzed in prepuberal children (6 to 8 years) in 3 school-based surveys performed by our group in Madrid in 1987, 1993, and 1999. A significant increase in plasma total cholesterol ( P < .05) and low-density lipoprotein-cholesterol (LDL-C) ( P < .01) levels in prepuberal children was observed over the last decade. However, the mean concentration of plasma HDL-C remained stable and very high. These high levels of plasma HDL-C in Spanish school children may help to explain why the coronary heart disease mortality rate in Spain is low compared with that in other developed countries.

Effect of dietary cholesterol with or without saturated fat on plasma lipoprotein cholesterol levels in the laboratory opossum (Monodelphis domestica) model for diet-induced hyperlipidaemia.

Laboratory opossums (Monodelphis domestica) show extreme genetic variability in their responsiveness to dietary lipids; a great proportion of the genetic variability in responsiveness is due to a single major gene. To determine whether the major gene for dietary response detected by genetic analysis in opossums is responsive to dietary cholesterol or dietary saturated fat, or a combination of both, we used males and females of susceptible and resistant lines of laboratory opossums that were 5 to 7 months old. The animals were challenged with three different experimental diets (high-cholesterol diets with or without high saturated fat from lard or coconut oil) and plasma lipoproteins were measured. Plasma and VLDL+LDL-cholesterol concentrations increased several-fold when the animals were fed the diet containing elevated cholesterol (P<0.001) or elevated cholesterol and fat (P<0.001) and differed between the two lines when they were fed high-cholesterol diets with or without fat (P<0.001). Plasma HDL-cholesterol concentrations were higher (P<0.05) in animals of the resistant line than in the susceptible line when they were fed the basal diet (550 (SEM 30) v. 440 (SEM 20) mg/l) and when they were fed the low-cholesterol and high-fat diet (600 (SEM 30) v. 490 (SEM 30) mg/l). Dietary coconut oil and lard had similar effects on plasma lipoprotein cholesterol concentrations in the susceptible line of opossums. A reduction in dietary cholesterol by 50 % with either the lard or coconut oil blunted the plasma cholesterol response. The results from the present studies suggest that the major gene for dietary response previously detected by genetic analysis in laboratory opossums affects the response to dietary cholesterol but not to saturated fat.

The effects of dietary caloric restriction on antioxidant status and lipid peroxidation in mild and severe streptozotocin-induced diabetic rats

Background: Dietary caloric restriction (CR) without malnutrition is effective in the control of diabetes mellitus by stabilizing glucose homeostasis and enhancing glycemic control. Mild and severe streptozotocin-induced diabetic and non-diabetic rats were subjected to caloric restriction and ad libitum feeding to evaluate their effects on oxidative stress and lipid profile in the plasma of experimental animals. Methods: Mild and severe diabetes were induced in Male Wistar rats by intraperitoneal injection of 35 and 65 mg/kg streptozotocin respectively. The experimental animals were subjected to 40% caloric restriction and ad libitum feeding for 9 weeks. Results: CR was effective in significantly reducing body weight, blood glucose, HbA IC and TG concentrations (all p<0.001) in mild diabetic rats and non-significantly improving the plasma HDL-cholesterol concentrations. However, CR did not produce any significant effect on the antioxidant enzyme activities and MDA concentrations in all the groups nor in any of the parameters measured in non-diabetic rats except their overall weight change. There were significant ( p<0.001) decreases in body weight and non-significant fluctuating results in HbA IC and HDL-cholesterol in severe diabetic animals. Conclusions: These results demonstrate that caloric restriction is most effective in mild than in non-diabetic or severe diabetic animals.

Selectively hydrogenated soybean oil with conjugated linoleic acid modifies body composition and plasma lipids in rats

The present study examined effects of a selectively hydrogenated soybean oil (SHSO) containing about 21% CLA on body composition, adipose depots and organ weights, and plasma lipid profiles in rats. Male Sprague Dawley rats were fed for 6 weeks a purified diet containing 0%, 1%, 3%, and 5% of SHSO. Different levels of SHSO supplementation did not significantly affect growth performance, although there was a trend toward decreased body weight gain with increasing dietary SHSO levels. The weights of inguinal, epididymal, and retroperitoneal adipose depot, but not mesenteric, were significantly influenced by dietary SHSO supplementation ( P < 0.05, P < 0.01 and P < 0.001, respectively). Although the absolute weight of body protein in the control rats was higher in SHSO-fed rats, the effect on absolute weight of body protein is diluted and eliminated when the data are adjusted for eviscerated carcass weight as a percentage base. Therefore, as dietary SHSO level increased, body protein as a percentage of carcass weight increased ( P < 0.05), although as dietary SHSO level increased, body fat proportion in carcass decreased ( P < 0.01). Plasma triglycerides (TG) and total cholesterol (TC) concentrations were beneficially decreased, and HDL-cholesterol (HDL-C) to TC ratio was also beneficially increased by SHSO supplementation ( P < 0.05, P < 0.001, and P < 0.01, respectively). However, plasma HDL-C concentration undesirably decreased with dietary SHSO supplementation ( P < 0.05). The present study observed that body composition and plasma lipids were beneficially modulated by SHSO supplementation at least 3% levels (0.6% of CLA), and suggested that SHSO is a useful fat source because of the high level of CLA.

Low-density lipoprotein particle size and its regulatory factors in school children.

Small low-density lipoprotein (LDL) particles are more atherogenic than larger LDL particles. To help prevent atherosclerotic coronary heart diseases, it may be useful to understand risk factors during childhood. In the present study, we evaluated LDL size and its relationship to other risk factors for atherosclerotic coronary heart disease. LDL size was measured by 2-15% gradient gel electrophoresis in 586 Japanese children (316 boys and 270 girls). Plasma lipids, apolipoproteins (apo), glucose, and insulin were also determined by conventional methods. Pattern B (LDL size < 25.5 nm) was found in 10.8% of boys and 4.4% of girls. Children with pattern B had a higher body mass index (BMI) and insulin resistance and a more atherogenic lipoprotein profile [higher triglycerides, higher apoB, and lower high-density lipoprotein cholesterol (HDL-C)] than children with pattern A (LDL size > or = 25.5 nm). BMI, insulin resistance, and plasma concentrations of triglycerides, glucose, and insulin decreased and plasma concentrations of HDL-C and apoA-I increased as LDL size increased. HDL-C and insulin in boys, and BMI, HDL-C, and apoA-I in girls predicted 22.9 and 28.1% of the variability of LDL size, respectively. LDL size was correlated with BMI and plasma concentrations of HDL-C, apoA-I, and insulin. Although the contribution of these parameters to LDL size in children was less than that in adults, improvement of these parameters by changes in lifestyle might be important for preventing the development of atherosclerosis even in children.

Comparative effects of emu and olive oil on aortic early atherosclerosis and associated risk factors in hypercholesterolemic hamsters

The comparative cholesterol lowering and antiatherosclerotic properties of emu oil and olive oil were evaluated in four groups ( n = 8) of hamsters fed a nonpurified diet containing either 10% coconut oil crude and refined, emu oil, and olive oil and 0.05% cholesterol (wt/wt) for 8 weeks. Hamsters fed the olive and emu oil diets had significantly lower concentrations of plasma total cholesterol (−31%, and −25%; P < 0.05, respectively) and low-density lipoprotein cholesterol (LDL-C) (−50%, and −41%; P < 0.05, respectively) compared to the coconut oil–fed hamsters, with no significant differences in plasma high-density lipoprotein cholesterol (HDL-C) or triacylglycerol (TAG) concentrations. Compared to the coconut oil–fed animals, hamsters fed the emu oil and olive oil–containing diets had reduced aortic cholesterol ester concentrations (−20% and −60%, respectively). The present study suggests that compared to a diet containing coconut oil, both emu oil and olive oil are capable of reducing aortic early atherosclerosis in hypercholesterolemic hamsters.