Biomedical subjects

Benoît Lamarche

Publications and source records attributed to Benoît Lamarche.

At least 55 records · Page 3Linked to original sources

PubMed2004

Effect of a nutritional intervention promoting the Mediterranean food pattern on electrophoretic characteristics of low-density lipoprotein particles in healthy women from the Québec City metropolitan area.

The objective of the present study was to evaluate the effect of a nutritional intervention promoting the Mediterranean food pattern in free-living conditions on LDL electrophoretic characteristics in a group of seventy-one healthy women, aged between 30 and 65 years. The 12-week nutritional intervention consisted of two courses on nutrition and seven individual sessions with a dietitian. The first course provided information on the Mediterranean food pattern and the second was a cooking lesson. LDL peak particle diameter (LDL-PPD) and cholesterol levels in small (LDL-cholesterol<255 A) and large LDL fractions (LDL-cholesterol>260 A) were obtained by 2-16 % polyacrylamide gel electrophoresis of whole plasma. The sample was divided on the basis of baseline LDL-PPD using tertiles of the distribution (258.4 A and 260.0 A). Among the total sample of women, no significant change in LDL-PPD was observed in response to the nutritional intervention. However, subjects who at baseline were in the first tertile of the LDL-PPD distribution (<258.4 A) showed a significant increase in LDL-PPD and in the proportion of LDL %>260 A in response to the 12-week nutritional intervention (P<0.05). In contrast, LDL-PPD decreased significantly (P=0.007) among women with large LDL particles at baseline (LDL-PPD >260 A) while the proportion of LDL %<255 A and of LDL %>260 A remained unchanged. To conclude, changes in the food pattern, in response to a nutritional intervention promoting the Mediterranean food pattern, were accompanied by beneficial modifications in LDL electrophoretic characteristics in women who were characterised at baseline by smaller LDL particles.

Adult↗

PubMed2004

Combined effects of a dietary portfolio of plant sterols, vegetable protein, viscous fibre and almonds on LDL particle size.

Studies conducted in the last 20 years have led to the identification of small dense LDL as an important risk factor for CVD. Consumption of plant sterols, soyabean proteins, viscous fibre and nuts are known to modulate the risk of CVD favourably through their cholesterol (Chol)-lowering properties, both independently and more recently in combination. Nevertheless, their combined impact on the LDL particle size phenotype has never been tested. In the present study, we assessed the effect of incorporating concurrently plant sterols (1 g/4.2 MJ), soyabean protein (23 g/4.2 MJ), viscous fibre (9 g/4.2 MJ) and almonds (15 g/4.2 MJ) into a diet very low in saturated fat in twelve patients with mildly elevated plasma LDL-Chol levels. Fasting blood lipids were obtained at the start of the study and at 2-week intervals during the 4-week study. The diet-induced reduction in plasma LDL-Chol of 30.0 (se 3.0) % (P<0.0001) was attributed to concurrent reductions in the serum Chol concentrations of large (>26.0 nm-30 (se 8) %, P<0.001), medium (25.5-26.0 nm-29 (se 3) %, P<0.001) and small (<25.5 nm-21 (sd 6) %, P<0.01) LDL particles, with near maximal reductions seen by week 2. These results indicate that foods and dietary components advocated for their potential to reduce the risk of CVD are effective in reducing serum concentrations of all LDL fractions including small dense LDL, thus potentially further contributing to an overall lower risk of CVD.

Adult↗

PubMed2004

Metabolic syndrome and effects of conjugated linoleic acid in obesity and lipoprotein disorders: the Québec experience.

The health hazards of obesity are well established. However, the fact that all obese individuals are not at equal risk of developing a disease is being increasingly recognized. The regional distribution of body fat has been identified as an important component of the obesity-related health hazards. Among obese individuals, those who accumulate fat predominantly in the abdominal area are more likely to present several metabolic perturbations of the metabolic syndrome, such as increased plasma triacylglycerol and apolipoprotein B concentrations, an elevated ratio of total cholesterol to HDL cholesterol, reduced plasma HDL-cholesterol concentrations, and small, dense LDL particles. This short review focuses on the risk associated with specific features of metabolic syndrome with use of data from the Québec Cardiovascular Study, an ongoing prospective study of traditional and nontraditional risk factors for ischemic heart disease in men. Recent data on the effect of conjugated linoleic acid on risk factors associated with metabolic syndrome are briefly reviewed. Data available to date suggest that conjugated linoleic acid might not be an appropriate dietary alternative for the treatment of metabolic syndrome and its complications.

Cardiovascular Diseases↗

PubMed2004

Soy protein favorably affects LDL size independently of isoflavones in hypercholesterolemic men and women.

We assessed the independent effect of soy protein relative to animal protein and of isoflavones on various electrophoretic characteristics of LDL particles. LDL particles were characterized by polyacrylamide gradient gel electrophoresis in 36 moderately hypercholesterolemic men and women (LDL cholesterol > 3.36 mmol/L). All subjects consumed in random order each of the four diets (soy protein depleted of isoflavones, soy protein enriched in isoflavones, animal protein with no added isoflavones, and animal protein with added isoflavones) for 6 wk. Consumption of soy protein was associated with a larger LDL peak particle size relative to animal protein (P < 0.01). Soy protein also decreased the cholesterol levels in LDL < 25.5 nm by 12.3% (P < 0.001) and increased cholesterol levels in LDL > 26.0 nm by 14.3% (P < 0.05) relative to animal protein. Isoflavones did not affect these LDL particle characteristics. Soy protein shifted LDL particle distribution to a less atherogenic pattern and this effect is independent of soy's isoflavone component.

Animals↗

PubMed2004

Unesterified plant sterols and stanols do not affect LDL electrophoretic characteristics in hypercholesterolemic subjects.

The extent to which sterols and stanols modulate LDL particle size is unknown. We examined the effects of supplementation with unesterified plant sterols and stanols on several LDL electrophoretic characteristics. Healthy hypercholesterolemic subjects (n = 14) consumed each of four experimental diets contained plant sterols (S), plant stanols (SN), a 50:50 mixture of sterols and stanols (SSN), or cornstarch (control) in a randomized crossover design. The butter component of the diet was blended with unesterified sterols and stanols at a dose of 1.8 g/d. The LDL particles were characterized by polyacrylamide gradient gel electrophoresis of whole plasma. LDL cholesterol (LDL-C) concentrations decreased by 8.8, 13.6, and 13.1% in the S, SN, and SSN groups, respectively (P < 0.01) with a significant increase of 4.3% in the control group. None of the treatments with sterols and stanols induced significant changes in LDL peak particle diameter or in the cholesterol levels of the small LDL subfraction (<25.5 nm). The reduction in plasma LDL-C levels with SN consumption was due mainly to a decrease (P < 0.05) in the concentration of cholesterol in the large subfraction (>26.0 nm). The significant reduction in plasma LDL-C concentrations by sterol and stanol consumption in subjects was not paralleled by any beneficial changes in LDL electrophoretic characteristics.

Cholesterol, HDL↗

PubMed2003

Characterization of a novel mutation causing hepatic lipase deficiency among French Canadians.

Individuals with hepatic lipase (HL) deficiency are often characterized by elevated levels of triglycerides (TGs) and cholesterol. The aim of the present study was to characterize the molecular defect leading to severe HL deficiency in a Québec-based kindred. In the proband and two of her brothers, the very low to undetectable HL activity resulted from compound heterozygosity for two rare HL gene mutations, a previously unknown missense mutation in exon 5 designated A174T and the previously reported T383M mutation in exon 8 of the HL gene. The mutation at codon 174 resulted in the substitution of alanine for threonine, a polar amino acid, in a highly conserved nonpolar region of the protein involved in the catalytic activity of the enzyme. The severe HL deficiency among the three related compound heterozygotes was associated with a marked TG enrichment of LDL and HDL particles. The two men with severe HL deficiency also presented with abdominal obesity, which appeared to amplify the impact of HL deficiency on plasma TG-rich lipoprotein levels. Our results demonstrated that HL deficiency in this Québec kindred is associated with an abnormal lipoprotein-lipid profile, which may vary considerably in the presence of secondary factors such as abdominal obesity.

Abdomen↗

PubMed2003

Concordance/discordance between plasma apolipoprotein B levels and the cholesterol indexes of atherosclerotic risk.

The objective of the present study was to examine concordance/discordance among 4 atherogenic indexes of cardiovascular risk: plasma total cholesterol, low-density lipoprotein (LDL) cholesterol, non-high-density lipoprotein (non-HDL) cholesterol, and apolipoprotein B-100 (apoB). Analyses were conducted in a cohort of 2,103 men without coronary artery disease (CAD) at the onset of the Quebec Cardiovascular Study. Although there were strong and highly significant correlations among the 4 risk indexes (0.78 < r < 0.97), only 50% of all subjects had concordant apoB and LDL cholesterol levels (i.e., values that fell into the same quintile of the population distribution). Moreover, concordance/discordance was not the same throughout the range of both variables; it was greater at the extremes of their respective distributions (65%), but significantly less in the midpoints (<40%). ApoB appeared to be more concordant with non-HDL cholesterol than with LDL cholesterol, although >1/3 of all subjects had discordant levels. Kappa analysis confirmed that there was only fair agreement between apoB and total or LDL cholesterol (0.38 and 0.36, respectively) and only moderate agreement between non-HDL cholesterol and apoB (0.47). Finally, a significant proportion of subjects (528 of 2,103) who had disproportionately higher apoB levels than would have been predicted based on their LDL cholesterol concentrations was more obese and manifested several features of the metabolic syndrome. They also had a significantly increased cardiovascular risk. In summary, plasma apoB and the various cholesterol indexes are complementary rather than competitive indexes of atherosclerotic risk and provide further evidence as to why measurement of apoB should be part of a standard lipoprotein assessment of CAD risk.

Aged↗

PubMed2003

Evidence for a major quantitative trait locus on chromosome 17q21 affecting low-density lipoprotein peak particle diameter.

BACKGROUND: Several lines of evidence suggest that small dense LDL particles are associated with the risk of coronary heart disease. Heritability and segregation studies suggest that LDL particle size is characterized by a large genetic contribution and the presence of a putative major genetic locus. However, association and linkage analyses have thus far been inconclusive in identifying the underlying gene(s). METHODS AND RESULTS: An autosomal genome-wide scan for LDL peak particle diameter (LDL-PPD) was performed in the Québec Family Study. A total of 442 markers were genotyped, with an average intermarker distance of 7.2 cM. LDL-PPD was measured by gradient gel electrophoresis in 681 subjects from 236 nuclear families. Linkage was tested by both sib-pair-based and variance components-based linkage methods. The strongest evidence of linkage was found on chromosome 17q21.33 at marker D17S1301, with an LOD score of 6.76 by the variance-components method for the phenotype adjusted for age, body mass index, and triglyceride levels. Similar results were obtained with the sib-pair method (P<0.0001). Other chromosomal regions harboring markers with highly suggestive evidence of linkage (P< or =0.0023; LOD > or =1.75) include 1p31, 2q33.2, 4p15.2, 5q12.3, and 14q31. Several candidate genes are localized under the peak linkages, including apolipoprotein H on chromosome 17q, the apolipoprotein E receptor 2, and members of the phospholipase A2 family on chromosome 1p as well as HMG-CoA reductase on chromosome 5q. CONCLUSIONS: This genome-wide scan for LDL-PPD indicates the presence of a major quantitative trait locus located on chromosome 17q and others interesting loci influencing the phenotype.

Adult↗

PubMed2003

Effect of plasma C-reactive protein levels in modulating the risk of coronary heart disease associated with small, dense, low-density lipoproteins in men (The Quebec Cardiovascular Study).

This purpose of this study was to investigate how plasma C-reactive protein (CRP), a nonspecific acute-phase reactant, modulates the risk of coronary heart disease (CHD) associated with the small, dense, low-density lipoprotein (LDL) phenotype. LDL particle size and plasma CRP were measured in the Quebec Cardiovascular Study cohort of 2,025 men free of CHD at baseline, among whom 103 had a first CHD event during a 5-year follow-up period. Plasma CRP levels were measured using the Behring Latex-Enhanced (highly sensitive) CRP assay. LDL particle size phenotype was characterized using 2% to 16% polyacrylamide gradient gel electrophoresis. There were weak but significant associations between plasma CRP levels and features of LDL size, such as the proportion of LDL with a diameter <255 A (r = 0.09, p <0.001) and LDL peak particle size (r = -0.09, p <0.001). Variations in plasma CRP levels modulated the risk of CHD associated with small LDL peak particle size (relative risk 4.3 vs 2.5 in men with high vs low plasma CRP levels, respectively) and with an elevated proportion of LDL <255 A (relative risk 6.6 vs 3.0). Thus, increased plasma CRP levels further elevate the risk of CHD associated with having small, dense LDL particles.

Age Distribution↗

PubMed2003

Heritability of LDL peak particle diameter in the Quebec Family Study.

LDL size has been associated with the risk of coronary heart disease. The objective of the present study was to verify whether familial factors influence LDL peak particle diameter (LDL-PPD), a quantitative trait reflecting the size of the major LDL subclass. LDL-PPD was measured by 2-16% polyacrylamide gradient gel electrophoresis in 681 members of 236 nuclear families participating in the Quebec Family Study. LDL-PPD was adjusted for age (LDL-PPD1), age and body mass index (LDL-PPD2), or age, body mass index, and plasma triglyceride levels (LDL-PPD3) separately in men and women. The residual scores were used to test for familial aggregation, using an ANOVA and to compute maximum likelihood estimates of familial correlations. The ANOVA test revealed that family lines accounted for 47.4%, 46.7%, and 48.9% of the variance in the LDL-PPD1, LDL-PPD2, and LDL-PPD3 phenotypes, respectively. The pattern of familial correlations revealed no significant spouse correlations but significant parent-offspring and sibling correlations for the three LDL-PPD phenotypes, with maximal heritability estimates of 59%, 58%, and 52% for LDL-PPD1, LDL-PPD2, and LDL-PPD3, respectively. These results suggest that LDL-PPD strongly aggregates in families, and that the familial resemblance appears to be primarily attributable to genetic factors. Genes responsible for this genetic contribution remain to be identified.

Adult↗

PubMed2003

Postprandial hyperlipidemia: another correlate of the "hypertriglyceridemic waist" phenotype in men.

Fasting hypertriglyceridemia has been reported to be predictive of an exaggerated triglyceride (TG) response to an oral fat load. Abdominal obesity has also been associated with postprandial hyperlipidemia. The objective of the present study was to quantify the contribution of abdominal obesity and fasting hypertriglyceridemia to the magnitude of postprandial lipemia. For that purpose, potential differences in postprandial TG-rich lipoprotein (TRL) levels were examined among men characterized by the absence/presence of the "hypertriglyceridemic waist" phenotype following a standardized breakfast with a high fat content (64% calories as fat). Sixty-nine men (mean age +/- S.D.: 45.1 +/- 10.5 years) were classified according to waist girth (< 90 or >/ or = 90 cm) and fasting TG concentrations (< 2.0 or > or = 2.0 mmol/l). Subjects characterized by "hypertriglyceridemic waist" (waist > or = 90 cm and fasting TG > or = 2.0 mmol/l) showed the highest TRL-TG concentrations (P < 0.0001) throughout the entire postprandial period (8 h) as well as elevated concentrations of apolipoprotein (apo) B-48 and apo B-100 in all TRL fractions (large, medium and small) compared to subjects with low fasting TG levels who had waist girth values either above or below 90 cm. These higher postprandial TRL-TG levels among carriers of the "hypertriglyceridemic waist" phenotype also led to significantly greater postprandial TG-total area under the curve (AUC) in total TRLs resulting mainly from the increased concentrations of large- and medium-sized TRLs. Furthermore, subjects characterized by the "hypertriglyceridemic waist" phenotype displayed higher fasting insulin concentrations and postprandial insulin AUC compared to men with low fasting plasma TG levels and low waist girth values. In conclusion, results of the present study indicate that postprandial hyperlipidemia is associated with the simultaneous presence of abdominal obesity and elevated fasting TG concentrations: a condition that we have described as the "hypertriglyceridemic waist" phenotype.

Adipose Tissue↗

PubMed2003

Influence of hydrogenated fat and butter on CVD risk factors: remnant-like particles, glucose and insulin, blood pressure and C-reactive protein.

Dietary trans fatty acids/partially-hydrogenated fat has been associated with increased risk of developing cardiovascular disease (CVD), possibly greater than predicted from changes in lipoprotein levels. To explore this issue further potential risk factors were assessed in subjects provided with each of six diets in randomized order containing as the major source of fat: soybean oil, semi-liquid margarine, soft margarine, shortening, traditional stick margarine or butter. Plasma fatty acid profiles reflected diet, with triglyceride and phospholipid subfractions affected to a greater extent than cholesteryl ester. Non-fasting LDL-cholesterol levels were 144+/-27, 141+/-27, 146+/-26, 148+/-30, 151+/-29 and 165+/-31 mg/dl (P<0.001) and total cholesterol/HDL-cholesterol ratios were 5.50+/-1.25, 5.54+/-1.50, 5.69+/-1.29, 5.82+/-1.40, 6.11+/-1.30 and 5.94+/-1.43 (P=0.011), respectively, whereas other lipoprotein levels were not significantly different. Remnant-like particles levels were unaffected by dietary fat, either in the fasting or non-fasting state. Differences in fasting insulin and glucose levels were small and would not be predicted to have a large impact on glucose homeostasis. There was no significant effect of dietary fat type on C-reactive protein levels or blood pressure. These data suggest that, as previously demonstrated, the major CVD risk factor adversely affected by dietary trans fatty acids/partially-hydrogenated fat is LDL-cholesterol levels and total cholesterol/HDL-cholesterol ratios.

Aged↗

PubMed2003

Influences of apolipoprotein E polymorphism on the response of plasma lipids to the ad libitum consumption of a high-carbohydrate diet compared with a high-monounsaturated fatty acid diet.

The purpose of this study was to assess the contribution of the apolipoprotein E (apoE) polymorphism and factors, such as age and waist circumference, to variations in plasma low-density lipoprotein-cholesterol (LDL-C) response following ad libitum consumption of a diet rich in complex carbohydrates (high-CHO: 58% of energy as CHO) versus a diet rich in fat and monounsaturated fatty acids (high-MUFA: fat, 40% of energy and 22% as MUFA). Sixty-five men participated in this parallel 6- to 7-week study involving either a high-CHO or a high-MUFA diet. Fasting plasma lipid profile and anthropometry were determined at the beginning and at the end of the dietary period. The high-CHO and high-MUFA diets both induced significant (P<.01) and comparable reductions in body weight and waist circumference. These changes were associated with a significant (P<.01) and comparable decrease in LDL-C (-19% and -16%, respectively). Stepwise multiple regression analyses showed that 32% of the variation in the LDL-C response to the high-CHO diet was attributable to the apoE polymorphism (18.5%, P=.04) and waist circumference (13.5%, P=.03) indicating that men with a waist circumference greater than 100 cm and the E2 allele had the greatest reduction in plasma LDL-C after the high-CHO diet. On the other hand, in the high-MUFA group, waist circumference was the only significant contributing factor to the LDL-C response and accounted for 44.5% of its variance. In conclusion, the plasma LDL-C response to ad libitum comsumption of a high-CHO and a high-MUFA diets are not modulated to the same extent by the apoE polymorphism and waist circumference.

Adult↗

PubMed2003

Impact of postprandial variation in triglyceridemia on low-density lipoprotein particle size.

The fasting atherogenic dyslipidemia of visceral obesity, which includes the presence of small, dense low-density lipoprotein (LDL) particles, is predictive of an increased risk of coronary heart disease (CHD). It has also been suggested that progression of atherosclerosis may be accelerated in the presence of postprandial hyperlipidemia independently from the fasting dyslipidemic state. Studies have shown that the best predictor of postprandial hyperlipidemia and of the small, dense LDL phenotype is fasting triglyceride (TG) concentration. In the present study, we evaluated the impact of postprandial hypertriglyceridemia on the variation in LDL particle size. Fasting (0 hour) and postprandial changes (2, 4, 6, and 8 hours) in LDL particle size were measured by nondenaturing 2% to 16% polyacrylamide gel electrophoresis in a sample of 49 men (mean age +/- SD: 46.6 +/- 9.2 years) who underwent a standardized breakfast with a high-fat (64% calories as fat) content. The postprandial increase in TG levels was associated with a transient reduction in LDL particle size, the most substantial reduction being observed 4 hours (-1.0 +/- 2.4 A) after the oral fat load. Although there were strong correlations between TG-rich lipoprotein (TRL)-TG levels and LDL particle size in the fasting state (r=-0.71, P<.0001) as well as 4 hours after the oral fat load (r=-0.70, P<.0001), changes in TRL-TG concentrations during the postprandial state (from time 0 to 4 hours) were not associated with changes in LDL particle size during this period (r=-0.04, not significant [NS]). However, among subgroups of men matched for similar fasting TRL-TG levels (n=12), subjects with the highest total area under the curve (AUC) of TRL-TG after the fat load were characterized by smaller LDL particle size at 6 and 8 hours compared with men with the lowest AUC TRL-TG (P<.02). Men displaying the highest postprandial AUC TRL-TG were also characterized by the greatest accumulation of visceral adipose tissue (AT) (P<.05). These results indicate that the hypertriglyceridemic (hyperTG) state induced by a high-fat meal is associated with a transient reduction in LDL peak particle diameter, which is not proportionate, however, to the level of TG achieved in the postprandial state. Furthermore, despite similar TG levels at baseline, viscerally obese men with an impaired postprandial lipemia had smaller LDL particles at the end of the oral fat load than obese men with a lower accumulation of visceral AT.

Adult↗

PubMed2003

Visceral obesity attenuates the effect of the hepatic lipase -514C>T polymorphism on plasma HDL-cholesterol levels in French-Canadian men.

UNLABELLED: The dyslipidemic state of visceral obesity is characterized by increased plasma triglyceride (TG) levels, low HDL-cholesterol concentrations and alterations in LDL composition and concentration. A functional, non-coding -514C>T single nucleotide polymorphism (SNP) of the hepatic lipase gene (LIPC) has been related to variation in HDL-cholesterol concentrations. OBJECTIVES: To investigate the hypotheses that the LIPC -514C>T polymorphism may be associated with a deteriorated lipoprotein-lipid profile and that environmental factor, such as abdominal obesity, alters this association. METHODS: A total of 235 French-Canadian men from the greater Quebec City area were assigned into three groups on the basis of their LIPC -514C>T SNP, including 149 CC homozygotes, 75 CT heterozygotes, and 11 TT homozygotes. RESULTS: In the present study, the highest values of BMI, waist circumference, and accumulation of visceral adipose tissue (VAT) were observed among TT homozygotes (p<0.05). After adjustment for age and BMI, TT homozygotes still showed higher plasma apolipoprotein (apo) AI and HDL-TG concentrations than the two other groups (p<0.05). When the two genotype groups (CC vs CT/TT) were further divided on the basis of VAT accumulation using a cut-off point of 130 cm(2) (high vs low) it appears that irrespective of the genotype subjects with low VAT had higher HDL(2)-cholesterol concentrations (p<0.0001). However, lean carriers of the T allele had higher plasma HDL(2)-cholesterol levels than lean CC homozygotes. The beneficial effect of the T allele on plasma HDL(2)-cholesterol levels was abolished in the presence of visceral obesity (VAT>130 cm(2)). CONCLUSION: In summary, the presence of visceral obesity attenuates the impact of the LIPC -514C>T polymorphism on plasma HDL(2)-cholesterol levels.

Adult↗

PubMed2003

Variations in body composition and plasma lipids in response to a high-carbohydrate diet.

OBJECTIVE: To examine the extent to which variations in body composition modulate changes in the lipid profile in response to the ad libitum consumption of a diet rich in carbohydrates (CHOs) (high-CHO diet: 58% of energy as CHOs) or high in fat and in monounsaturated fatty acids (MUFAs) (high-MUFA diet: 40% of energy as fat, 23% as MUFAs). RESEARCH METHODS AND PROCEDURES: Sixty-three men were randomly assigned to one of the two diets that they consumed for 6 to 7 weeks. Body composition and fasting plasma lipid levels were measured at the beginning and the end of the dietary intervention. RESULTS: The high-CHO and high-MUFA diets induced significant and comparable reductions in body weight and waist circumference. These changes were accompanied by significant and comparable (p < 0.01) reductions in total plasma cholesterol and low-density lipoprotein cholesterol levels. However, the high-MUFA diet had more beneficial effects on plasma triglyceride concentrations (p < 0.01) and on plasma high-density lipoprotein cholesterol levels (p = 0.02) compared with the high-CHO diet. Diet-induced changes in waist circumference were significantly associated with changes in low-density lipoprotein cholesterol levels in the high-CHO group (r = 0.39, p = 0.03) but not in the high-MUFA group (r = 0.16, p = 0.38). DISCUSSION: Improvements in plasma lipids induced by the ad libitum consumption of a high-CHO diet seem to be partly mediated by changes in body weight, whereas lipid changes induced by the high-MUFA diet seem to be independent of changes in body weight.

Adipose Tissue↗

PubMed2003

Effect of different forms of dietary hydrogenated fats on LDL particle size.

BACKGROUND: Dietary trans fatty acids (FAs), which are formed during the process of hydrogenating vegetable oil, are known to increase plasma LDL-cholesterol concentrations. However, their effect on LDL particle size has yet to be investigated. OBJECTIVE: We investigated the effect of trans FA consumption on the electrophoretic characteristics of LDL particles. DESIGN: Eighteen women and 18 men each consumed 5 experimental diets in random order for 35-d periods. Fat represented 30% of total energy intake in each diet, with two-thirds of the fat in the form of semiliquid margarine (0.6 g trans FAs/100 g fat), soft margarine (9.4 g trans FAs/100 g fat), shortening (13.6 g trans FAs/100 g fat), stick margarine (26.1 g trans FAs/100 g fat), or butter, which was low in trans FAs (2.6 g trans FAs/100 g fat) but rich in saturated fat. LDL particle size and distribution were characterized by nondenaturing, 2-16% polyacrylamide gradient gel electrophoresis. RESULTS: Relative to the LDL particle size observed after consumption of the butter-enriched diet, LDL particle size decreased significantly and in a dose-dependent fashion with increasing amounts of dietary trans FAs (P < 0.001). Cholesterol concentrations in large (> 260 A) and medium-sized (255-260 A) LDL particles also increased proportionately to the amount of trans FAs in the diet. CONCLUSION: Consumption of dietary trans FAs is associated with a deleterious increase in small, dense LDL, which further reinforces the importance of promoting diets low in trans FAs to favorably affect the lipoprotein profile.

Aged↗

PubMed2003

High carbohydrate and high monounsaturated fatty acid diets similarly affect LDL electrophoretic characteristics in men who are losing weight.

We compared the effects of ad libitum consumption of a defined high complex carbohydrate (CHO) diet (% of energy: CHO, 58.3; fat, 25.8) vs. a defined high monounsaturated fatty acid (MUFA) diet (% of energy: CHO, 44.7; fat, 40.1; MUFA, 22.5) on LDL electrophoretic characteristics. Healthy men [n = 65; age, 37.5 +/- 11.2 (mean +/- SD) y; BMI, 29.2 +/- 4.9 kg/m2] were randomly assigned to one of the two diets that they consumed for 6-7 wk. The high CHO diet significantly reduced body weight (-2%). The diet-induced reduction in plasma LDL cholesterol (C) levels in the high-CHO diet group was due mainly to concurrent reductions in the cholesterol content of small (<25.5 nm, P < 0.01) and medium-sized LDL (25.5-26.0 nm, P = 0.01). The high MUFA diet also reduced body weight, and LDL-C and LDL-apolipoprotein (apo)B levels, which were comparable to those in the high CHO group. The cholesterol levels of small LDL particles tended to be reduced (P = 0.24) in the high MUFA group (-12%), similar to changes in the high CHO group. These results suggest that, when associated with weight loss, ad libitum consumption of high CHO and high MUFA diets may be considered to be equally beneficial for the management of LDL-related atherogenic dyslipidemia. However, the high MUFA diet more favorably affected triglyceride levels, suggesting that it may be preferable to a high CHO diet in cardiovascular disease prevention.

Adult↗