DIETARY ANDGENETICEFFECTS ONLOW-DENSITYLIPOPROTEINHETEROGENEITY

Association between dietary patterns and cardiovascular diseases: A review

Cardiovascular disease (CVD), especially atherosclerosis, is the primary cause of global deaths. It accounts for millions of deaths annually. Even a small reduction in CVD through preventive treatment can have a substantial impact. Dietary patterns and substances are strongly linked to chronic diseases such as atherosclerosis, hypertension, heart failure, and type 2 diabetes. An unhealthy diet could lead to traditional risk factors such as LDL levels, TG levels, diabetes, and high blood pressure while accelerating atherosclerosis progression. Recent research has shown the potential of dietary interventions to prevent and treat cardiovascular disease, particularly through healthy dietary patterns such as the Mediterranean diet or DASH. In 2016, the World Health Organization (WHO) and the US Centers for Disease Control and Prevention (CDC) launched a new initiative aimed at enhancing the prevention and control of cardiovascular disease (CVD) by improving the management of CVD in primary care, including the optimization of dietary patterns. Here, this review summarizes several large cohort researches about the effects of dietary patterns on atherosclerosis, refines dietary components, and outlines some typical anti-atherosclerosis dietary agents. Finally, this review discusses recent mechanisms by which dietary interventions affect atherosclerosis progression.

Association of LDL-cholesterol subfractions with cardiovascular disorders: a systematic review

BACKGROUND

Cardiovascular disorders (CVDs) are the leading cause of death worldwide. This study aimed to evaluate the association between low-density lipoprotein (LDL) subfractions and cardiovascular disorders.

METHODS

To ensure the rigor of the systematic review, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were used. For this systematic review, a comprehensive search strategy was performed in important databases including PubMed, Scopus, Embase, International Statistical Institute (ISI) Web of Science, and google scholar from 2009 to February 2021. The following terms were used for systematic search: low-density lipoprotein, LDL, subfractions, subclasses, nuclear magnetic resonance, NMR, chromatography, high-pressure liquid, HPLC, cardiovascular disease, cerebrovascular, and peripheral vascular disease. Also, for evaluating the risk of bias, the Newcastle-Ottawa scale was employed.

RESULTS

At the end of the search process, 33 articles were included in this study. The results of most of the evaluated studies revealed that a higher LDL particle number was consistently associated with increased risk for cardiovascular disease, independent of other lipid measurements. Also, small dense LDL was associated with an increased risk of CVDs. There was no association between LDL subfraction and CVDs in a small number of studies.

CONCLUSIONS

Overall, it seems that the evaluation of LDL subclasses can be used as a very suitable biomarker for the assessment and diagnosis of cardiovascular diseases. However, further studies are required to identify the mechanisms involved.

Lipoprotein Subfractions as Markers for Predicting the Presence and Severity of Coronary Artery Disease in Patients Undergoing Coronary Angiography

Patients with coronary artery disease (CAD) often have normal blood cholesterol profiles that make it difficult to identify those at risk. The role of lipoprotein subfractions in the development of CAD has attracted increasing attention, and can further stratify risks. We enrolled 1578 patients undergoing coronary angiography and not taking any lipid-lowering drugs; 1033 of them were diagnosed with CAD. The severity of CAD was assessed using Gensini score (GS) and divided into 3 groups. Multivariate regression analysis showed that low-density lipoprotein particle 6 (LDL-P6) and lipoprotein (a) (Lp(a)) were independent risk factors for CAD, apart for the traditional risk factors. In receiver-operating characteristic (ROC) analysis for predicting the presence of CAD, the area under the ROC curve of traditional risk factors combined with Lp(a) and LDL-P6 for predicting CAD was .723, which was better than for traditional risk factors (P = .023). The plasma LDL-P6 and Lp(a) concentrations in the highest tertile GS group were significantly higher than that in the lowest GS group (P < .001). Stepwise linear regression analysis demonstrated positive correlations between Lp(a), LDL-P6 and GS (P = .007 and P < .001). LDL-P6 and Lp(a) are useful markers for predicting the presence and severity of CAD.

Trans fatty acids in food: A review on dietary intake, health impact, regulations and alternatives

Trans fats are desired by the edible oil industry as they impart firmness, plasticity, and oxidative stability to oil. However, clinical trials have demonstrated the adverse effects of trans fats in food on human health and nutrition. Regulatory actions have been taken up by government and non-government bodies worldwide to eliminate the presence of trans fats in the food supply. The World Health Organization (WHO) has launched a "REPLACE" action plan to eliminate trans-fat from the global food industry by 2023. A few enabling technologies are developed to mitigate trans fats namely, trait-enhanced oils, modification in the hydrogenation process, interesterification, fractionation, blending, and oleogelation. Some of them have the drawback of replacing trans-fat with saturated fats. Interesterification and oleogelation are in-trend techniques with excellent potential in replacing trans fats without compromising the desired functionality and nutritional quality attributes. This review presents an overview of trans fatty acid for example, its dietary intake in food products, possible adverse health impact, regulations, and approaches to reduce the usage of trans fats for food application. PRACTICAL APPLICATION: The requirement for the replacement of trans fatty acids (TFAs) in food supply globally has challenged the food industry to find a novel substitute for trans fats without compromising the desired functionality and nutritional property. This review presents detailed background on trans fats, their health impacts and current trends of reformulation of oils and fats to mitigate their presence in food supply chains. Information compiled in this paper will help food scientists and technologists, chemists, food processors, and retailers as there is an urgent need to find novel technologies and substitutes to replace trans fats in processed foods.

The effects of fat consumption on low-density lipoprotein particle size in healthy individuals: a narrative review

Cardiovascular disease (CVD) is the number one contributor to death in the United States and worldwide. A risk factor for CVD is high serum low-density lipoprotein cholesterol (LDL-C) concentrations; however, LDL particles exist in a variety of sizes that may differentially affect the progression of CVD. The small, dense LDL particles, compared to the large, buoyant LDL subclass, are considered to be more atherogenic. It has been suggested that replacing saturated fatty acids with monounsaturated and polyunsaturated fatty acids decreases the risk for CVD. However, certain studies are not in agreement with this recommendation, as saturated fatty acid intake did not increase the risk for CVD, cardiovascular events, and/or mortality. Furthermore, consumption of saturated fat has been demonstrated to increase large, buoyant LDL particles, which may explain, in part, for the differing outcomes regarding fat consumption on CVD risk. Therefore, the objective was to review intervention trials that explored the effects of fat consumption on LDL particle size in healthy individuals. PubMed and Web of Science were utilized during the search process for journal articles. The results of this review provided evidence that fat consumption increases large, buoyant LDL and/or decreases small, dense LDL particles, and therefore, influences CVD risk.

Risk Factors and Their Diagnostic Values for Ocular Metastases in Gastric Adenocarcinoma

Objective

Gastric adenocarcinoma originates from the glands in the superficial layer or mucosa of the stomach. It is prone to metastases, of which ocular metastasis (OM) is rare, but once it occurs the disease is considered more serious. The aim of this study was to investigate the risk factors for OM in gastric adenocarcinoma.

Methods

Patients with gastric adenocarcinoma were recruited to this study between June 2003 and July 2019. Demographic data and serological indicators (SI) were compared between patients with and without OM, and binary logistic regression was used to explore whether the relevant SI may be risk factors for OM of gastric adenocarcinoma. Receiver operating characteristic (ROC) curves were used to analyze different SIs for OM in gastric cancer patients.

Results

Chi-square tests showed significant between-groups difference in gender composition (P < 0.05), but not in age or histological grade (P > 0.05). t-test results showed that low-density lipoprotein (LDL) and carbohydrate antigen-724 (CA724) were significantly higher in patients with than without OM (P < 0.05). Binary logistic regression analysis showed that LDL was an independent risk factor for OM (P < 0.001). ROC curve analysis showed that the areas under the curves (AUC) for LDL and CA724 were 0.903 and 0.913 respectively, with higher AUC for combined LDL and CA724 (0.934; P < 0.001).

Conclusion

LDL and CA724 have value as predictors for OM in patients with gastric adenocarcinoma, with higher predictive value when these factors are combined.

Balanced high fat diet reduces cardiovascular risk in obese women although changes in adipose tissue, lipoproteins, and insulin resistance differ by race

BACKGROUND

We previously reported that consuming a balanced high fat diet (BHFD) wherein total saturated fat was reduced and total unsaturated fat increased by proportionately balancing the type of fat (1/3 saturated, 1/3 monounsaturated, 1/3 polyunsaturated) led to significant improvements in inflammatory burden, blood pressure, and vascular function in obese premenopausal European American (EA) and African American (AA) women.

OBJECTIVE

Here we compared changes in adipose tissue, lipoproteins, insulin resistance, and cardiovascular risk between EA and AA women.

METHODS

Dietary intakes, plasma fatty acids, lipids, apolipoproteins, lipoproteins, HOMA-IR and ASCVD risk was measured in 144 women who consumed BHFD for 16 weeks. Generalized linear modeling was performed while controlling for change in body weight.

RESULTS

EA women had greater reductions in visceral adipose tissue. Only EA women had significant reductions in fasting insulin levels (↓24.8%) and HOMA-IR (↓29%) scores. In EA women, the most significant improvements occurred in VLDL particle size (↑), apolipoprotein B levels (↑), serum TG (↓), number of plasma LDL particles (↓), and serum LDL-cholesterol (↓). In AA women, significant improvements occurred in HDL particle size (↑), number of large HDL particles (↑), and apolipoprotein AI levels (↑). Consequently, both groups had improved ASCVD risk scores (↓5.5%).

CONCLUSIONS

Consuming the balanced high fat diet led to significant reduction in cardiovascular risk factors in both groups. However, the pattern of response to BHFD differed with EA women responding more in components of the apolipoprotein B pathway versus AA women responding more in components of the apolipoprotein AI pathway.

Effects of a 6-month caloric restriction induced-weight loss program in obese postmenopausal women with and without the metabolic syndrome: a MONET study

OBJECTIVE

To compare the effects of a caloric restriction (CR) on body composition, lipid profile, and glucose homeostasis in obese postmenopausal women with and without metabolic syndrome (MetS).

METHODS

Secondary analyses were performed on 73 inactive obese postmenopausal women (age 57.7 ± 4.8 years; body mass index 32.4 ± 4.6 kg/m) who participated in the 6-month CR arm of a study of the Montreal-Ottawa New Emerging Team. The harmonized MetS definition was used to categorize participants with MetS (n = 20, 27.39%) and without MetS (n = 53, 72.61%). Variables of interest were: body composition (dual-energy X-ray absorptiometry), body fat distribution (computed tomography scan), glucose homeostasis at fasting state and during a euglycemic/hyperinsulinemic clamp, fasting lipids, and resting blood pressure.

RESULTS

By design, the MetS group had a worse cardiometabolic profile, whereas both groups were comparable for age. Fifty-five participants out of 73 displayed no change in MetS status after the intervention. Twelve participants out of 20 (or 60.0%) in the MetS group had no more MetS after weight loss (P = NS), whereas 6 participants out of 53 (or 11.3%) in the other group developed the MetS after the intervention (P = NS). Overall, indices of body composition and body fat distribution improved significantly and similarly in both groups (P between 0.03 and 0.0001). Furthermore, with the exception of triglyceride levels and triglycerides/high-density lipoprotein cholesterol ratio, which decrease significantly more in the MetS group (P ≤ 0.05), no difference was observed between groups for the other variables of the cardiometabolic profile.

CONCLUSIONS

Despite no overall significant effects on MetS, heteregeneous results were obtained in response to weight loss in the present study, with some improving the MetS, whereas other displaying deteriorations. Further studies are needed to identify factors and phenotypes associated with positive and negative cardiometabolic responses to CR intervention.

Effects of a very high saturated fat diet on LDL particles in adults with atherogenic dyslipidemia: A randomized controlled trial

Background

Previous studies have shown that increases in LDL-cholesterol resulting from substitution of dietary saturated fat for carbohydrate or unsaturated fat are due primarily to increases in large cholesterol-enriched LDL, with minimal changes in small, dense LDL particles and apolipoprotein B. However, individuals can differ by their LDL particle distribution, and it is possible that this may influence LDL subclass response.

Objective

The objective of this study was to test whether the reported effects of saturated fat apply to individuals with atherogenic dyslipidemia as characterized by a preponderance of small LDL particles (LDL phenotype B).

Methods

Fifty-three phenotype B men and postmenopausal women consumed a baseline diet (55%E carbohydrate, 15%E protein, 30%E fat, 8%E saturated fat) for 3 weeks, after which they were randomized to either a moderate carbohydrate, very high saturated fat diet (HSF; 39%E carbohydrate, 25%E protein, 36%E fat, 18%E saturated fat) or low saturated fat diet (LSF; 37%E carbohydrate, 25%E protein, 37%E fat, 9%E saturated fat) for 3 weeks.

Results

Compared to the LSF diet, consumption of the HSF diet resulted in significantly greater increases from baseline (% change; 95% CI) in plasma concentrations of apolipoprotein B (HSF vs. LSF: 9.5; 3.6 to 15.7 vs. -6.8; -11.7 to -1.76; p = 0.0003) and medium (8.8; -1.3 to 20.0 vs. -7.3; -15.7 to 2.0; p = 0.03), small (6.1; -10.3 to 25.6 vs. -20.8; -32.8 to -6.7; p = 0.02), and total LDL (3.6; -3.2 to 11.0 vs. -7.9; -13.9 to -1.5; p = 0.03) particles, with no differences in change of large and very small LDL concentrations. As expected, total-cholesterol (11.0; 6.5 to 15.7 vs. -5.7; -9.4 to -1.8; p<0.0001) and LDL-cholesterol (16.7; 7.9 to 26.2 vs. -8.7; -15.4 to -1.4; p = 0.0001) also increased with increased saturated fat intake.

Conclusions

Because medium and small LDL particles are more highly associated with cardiovascular disease than are larger LDL, the present results suggest that very high saturated fat intake may increase cardiovascular disease risk in phenotype B individuals. This trial was registered at clinicaltrials.gov (NCT00895141).

Trial registration

Clinicaltrials.gov NCT00895141.

State of the Art Reviews: Relationship Between Diet/ Physical Activity and Health

Obesity and 4 of the leading causes of death—heart disease, cancer, stroke, and type 2 diabetes mellitus—are related to lifestyle. The combination of a healthy weight, prudent diet, and daily physical activity clearly plays a role in primary, secondary, and tertiary prevention of these and other chronic diseases. Because nearly 65% of the adult population is overweight or obese, weight loss and maintenance are central to this review article. Improved lipid profiles, blood pressure, insulin sensitivity, and euglycemia are associated with weight loss or a normal body weight; thus, maintaining a healthy weight is a universal recommendation for health. The methods for improving lifestyle described in the section on obesity include assessing nutritional status and stages of change of the client, setting realistic goals, eating a diet high in fruits and vegetables with low-fat sources of dairy and protein, and achieving appropriate physical activity levels. The importance of physicians discussing weight with clients and vice versa is stressed. The common features of lifestyle-related diseases make them amenable to similar lifestyle interventions.

[Nutritional therapy in the obese patient with insulin resistance and cardiovascular risk]

Currently, each of the different scientific societies advocate one kind or another nutritional recommendations for patients with vascular risk. This variety of diets on the one hand enrich the nutritional therapeutic possibilities, but on the other can lead to some confusion, both for the patient and for the professional that advises. Furthermore, most studies assessing vascular risk mention a "diet" without defining or specifying to which kind of diet they refer, thereby introducing an important bias in the results of those studies. In fact, some of them bear a degree of contradiction. This review aims to shed some light on such a controversial topic.

Traditional dietary recommendations for the prevention of cardiovascular disease: do they meet the needs of our patients?

The characteristics of patients with CVD have changed: whereas smoking prevalence declines, obesity and metabolic syndrome are on the rise. Unfortunately, the traditional low-fat diet for the prevention of cardiovascular disease (CVD) still seems to be the “mainstream knowledge” despite contradicting evidence. But lowering LDL-cholesterol by the wrong diet even may be counterproductive, if sd-LDL is raised and HDL is lowered. New insights into the pathophysiology of insulin resistance and its influence on the effects of dietary changes have led to a better approach: (1) the higher a patient's insulin resistance, the more important is the glycemic load of the diet. (2) Fat quality is much more important than fat quantity. (3) The best principle for a reduced calorie intake is not fat counting, but a high volume diet with low energy density, which means fibre rich vegetables and fruits. (4) And finally, satiation and palatability of a diet is very important: there is no success without the patient's compliance. Thus, the best approach to the dietary prevention of CVD is a Mediterranean style low-carb diet represented in the LOGI pyramid. Dietary guidelines for the prevention of CVD should to be revised accordingly.

Effect of short-term low- and high-fat diets on low-density lipoprotein particle size in normolipidemic subjects

High-fat, low-carbohydrate diets have been shown to raise plasma cholesterol levels, an effect associated with the formation of large low-density lipoprotein (LDL) particles. However, the impact of dietary intervention on time-course changes in LDL particle size has not been investigated. To test whether a short-term dietary intervention affects LDL particle size, we conducted a randomized, double-blind, crossover study using an intensive dietary modification in 12 nonobese healthy men with normal plasma lipid profile. Participants were subjected to 2 isocaloric 3-day diets: high-fat diet (37% energy from fat and 50% from carbohydrates) and low-fat diet (25% energy from fat and 62% from carbohydrates). Plasma lipid levels and LDL particle size were assessed on fasting blood samples after 3 days of feeding on each diet. The LDL particles were characterized by polyacrylamide gradient gel electrophoresis. Compared with the low-fat diet, plasma cholesterol, LDL cholesterol, and high-density lipoprotein cholesterol were significantly increased (4.45 vs 4.78 mmol/L, P = .04; 2.48 vs 2.90 mmol/L, P = .005; and 1.29 vs 1.41 mmol/L, P = .005, respectively) following the 3-day high-fat diet. Plasma triglycerides and fasting apolipoprotein B-48 levels were significantly decreased after the high-fat diet compared with the low-fat diet (1.48 vs 1.01 mmol/L, P = .0003 and 9.6 vs 5.5 mg/L, P = .008, respectively). The high-fat diet was also associated with a significant increase in LDL particle size (255.0 vs 255.9 Å;P = .01) and a significant decrease in the proportion of small LDL particle (<255.0 Å) (50.7% vs 44.6%, P = .01). As compared with a low-fat diet, the cholesterol-raising effect of a high-fat diet is associated with the formation of large LDL particles after only 3 days of feeding.

Smaller Mean LDL Particle Size and Higher Proportion of Small Dense LDL in Korean Type 2 Diabetic Patients

BACKGROUND

Small dense low density lipoprotein (sdLDL) has recently emerged as an important risk factor of coronary heart disease.

METHODS

The mean LDL particle size was measured in 203 patients with type 2 diabetes mellitus (T2DM) and 212 matched subjects without diabetes using polyacrylamide tube gel electrophoresis. Major vascular complications were defined as stroke, angiographically-documented coronary artery disease or a myocardial infarction. Peripheral vascular stenosis, carotid artery stenosis (≥50% in diameter) or carotid artery plaque were considered minor vascular complications. Overall vascular complications included both major and minor vascular complications.

RESULTS

Diabetic patients had significantly smaller mean-LDL particle size (26.32 nm vs. 26.49 nm) and a higher percentage of sdLDL to total LDL compared to those of subjects without diabetes (21.39% vs. 6.34%). The independent predictors of sdLDL in this study were serum triglyceride level and body mass index (odds ratio [OR], 1.020 with P<0.001 and OR 1.152 with P<0.027, respectively). However, no significant correlations were found between sdLDL and major vascular complications (P=0.342), minor vascular complications (P=0.573) or overall vascular complications (P=0.262) in diabetic subjects.

CONCLUSION

Diabetic patients had a smaller mean-LDL particle size and higher proportion of sdLDL compared to those of subjects without diabetes. Obese diabetic patients with hypertriglyceridemia have an increased risk for atherogenic small dense LDL. However, we could not verify an association between LDL particle size and vascular complications in this study.

Endogenous and diet-induced hypercholesterolemia in nonhuman primates: effects of age, adiposity, and diabetes on lipoprotein profiles

Nonhuman primates (NHPs) share with humans many features of lipid metabolism and often develop all features of the metabolic syndrome, including hypertriglyceridemia and low high-density lipoprotein cholesterol, and have been used in many studies of potential therapeutics during the preclinical phase. Here we identify for the first time in middle-aged and older rhesus the natural occurrence of hypercholesterolemia, and this hypercholesterolemia develops despite maintenance on a low-cholesterol diet. The aims of this study were to (a) define normal and hypercholesterolemia in rhesus monkeys, (b) determine the factors associated with the development of hypercholesterolemia, (c) compare the lipoprotein profiles in adult rhesus monkeys fed a low-fat/low-cholesterol diet (LFLC) with the profiles of human subjects, and (d) determine the effect of a 16-week high-fat/high-cholesterol (HFHC) diet feeding on total cholesterol and lipoprotein profiles in middle-aged and older monkeys. In our colony, maintained on a constant diet with negligible cholesterol, the mean total cholesterol level in healthy nondiabetic monkeys was 3.7 ± 0.02 mmol/L, with hypercholesterolemia identified as the 95th percentile of the normal cholesterol distribution (≥5.2 mmol/L). Severe hypercholesterolemia developed in the HFHC-fed group; however, despite the high-fat diet composition, unexpectedly, no weight gain occurred in these NHPs. The diet-induced hypercholesterolemia differed significantly in lipoprotein pattern from that of the spontaneous hypercholesterolemia. In summary, despite ingesting only a LFLC, NHPs frequently develop hypercholesterolemia, reflecting lipoprotein patterns similar to human subjects; and this lipid profile of spontaneous hypercholesterolemia differs significantly from the hypercholesterolemia induced by an HFHC diet.

Exchanging carbohydrate or protein for fat improves lipid-related cardiovascular risk profile in overweight men and women when consumed ad libitum

BACKGROUND

The impact of low-fat diets on the plasma lipoprotein profile is incompletely understood.

METHODS

We conducted two 16-week dietary studies to compare the effects of a moderate-fat (mod-FAT) baseline diet with isocaloric and ad libitum low-fat diets rich in either carbohydrates (high-CHO, n = 16) or protein (high-PRO, n = 19) on plasma lipids, post-heparin lipase activities, cholesteryl ester transfer protein, and phospholipid transfer protein.

RESULTS

Switching from the mod-FAT to the isocaloric high-CHO diet lowered plasma high-density lipoprotein cholesterol concentrations (P < 0.001) and tended to increase triglyceride levels (P = 0.087). Cholesterol content in the larger, buoyant low-density lipoprotein (LDL) fractions decreased, whereas those of the very-low-density lipoprotein, intermediate-density lipoprotein, and smaller, denser LDL fractions tended to increase. These changes were largely reversed when subjects lost weight by consuming this high-CHO diet ad libitum. Switching from the mod-FAT diet to the isocaloric high-PRO diet did not increase cholesterol content in the small-dense LDL fraction and led to decreases in both LDL and high-density lipoprotein cholesterol in plasma (P < 0.001 for both).Consumption of the high-protein ad libitum diet accompanied by weight loss did not change plasma lipids further, except for a shift of cholesterol from dense low-density lipoprotein fractions to more buoyant low-density lipoprotein fractions. Cholesteryl ester transfer protein concentrations decreased with high-cholesterol feeding, whereas cholesteryl ester transfer protein concentrations and hepatic lipase and phospholipid transfer protein activities all decreased during high-protein feeding.

CONCLUSIONS

Both high-CHO and high-PRO diets improve plasma lipid-related risk of cardiovascular disease when consumed ad libitum.

Localization of genes for V+LDL plasma cholesterol levels on two diets in the opossum Monodelphis domestica

Plasma cholesterol levels among individuals vary considerably in response to diet. However, the genes that influence this response are largely unknown. Non-HDL (V+LDL) cholesterol levels vary dramatically among gray, short-tailed opossums fed an atherogenic diet, and we previously reported that two quantitative trait loci (QTLs) influenced V+LDL cholesterol on two diets. We used hypothesis-free, genome-wide linkage analyses on data from 325 pedigreed opossums and located one QTL for V+LDL cholesterol on the basal diet on opossum chromosome 1q [logarithm of the odds (LOD) = 3.11, genomic P = 0.019] and another QTL for V+LDL on the atherogenic diet (i.e., high levels of cholesterol and fat) on chromosome 8 (LOD = 9.88, genomic P = 5 x 10(-9)). We then employed a novel strategy involving combined analyses of genomic resources, expression analysis, sequencing, and genotyping to identify candidate genes for the chromosome 8 QTL. A polymorphism in ABCB4 was strongly associated (P = 9 x 10(-14)) with the plasma V+LDL cholesterol concentrations on the high-cholesterol, high-fat diet. The results of this study indicate that genetic variation in ABCB4, or closely linked genes, is responsible for the dramatic differences among opossums in their V+LDL cholesterol response to an atherogenic diet.

Lipoproteins and lipoprotein metabolism in periodontal disease

A growing body of evidence indicates that the incidence of atherosclerosis is increased in subjects with periodontitis - a chronic infection of the oral cavity. This article summarizes the evidence that suggests periodontitis shifts the lipoprotein profile to be more proatherogenic. LDL-C is elevated in periodontitis and most studies indicate that triglyceride levels are also increased. By contrast, antiatherogenic HDL tends to be low in periodontitis. Periodontal therapy tends to shift lipoprotein levels to a healthier profile and also reduces subclinical indices of atherosclerosis. In summary, periodontal disease alters lipoprotein metabolism in ways that could promote atherosclerosis and cardiovascular disease.

Reversal of small, dense LDL subclass phenotype by normalization of adiposity

Excess adiposity and high-carbohydrate diets have been associated with an atherogenic lipoprotein phenotype (ALP) characterized by increased concentrations of small, dense low-density lipoprotein (LDL) particles (pattern B). We tested whether weight loss and normalization of adiposity could reverse ALP in overweight men with pattern B. After consuming a moderate-carbohydrate, high-fat diet for 3 weeks, pattern B and nonpattern B (pattern A) men were randomized to a weight loss (n = 60 and n = 36, respectively) or control weight-stable arm (n = 20 and n = 17, respectively). Men in the weight loss arm consumed approximately 1,000 fewer calories per day over 9 weeks to induce an average approximately 9 kg weight loss. In the control group, weight stability was maintained for 4 weeks after randomization. Weight loss led to the conversion of pattern B to pattern A in 58% of baseline pattern B men. Among men who achieved BMIs of <25 kg/m(2) (62% of pattern B men vs. 83% of pattern A men), 81% of pattern B men converted to pattern A. Weight loss was associated with a significantly greater decrease in small, dense LDL subclass 3b in pattern B relative to pattern A men. The lipoprotein profiles of pattern A men who converted from pattern B were comparable to those of men with pattern A at baseline. Conversion of LDL subclass pattern B to pattern A and reversal of ALP can be achieved in a high proportion of overweight men by normalization of adiposity.

C18 hydroxy fatty acids as markers of lipid peroxidationex vivoandin vivo

Different C18 monohydroxy fatty acids (OHFAs) were evaluated for their usefulness as markers of plasma lipid peroxidation (unsaturated fatty acid oxidation) ex vivo and in vivo. First, plasma samples (n = 5) were exposed for 3 h to different radical fluxes ex vivo. The formation of OHFAs was assessed by using varying concentrations of Cu2+ ions and AAPH (2,2'-azobis(2-amidinopropane) hydrochloride) as radical flux initiators. Secondly, a cross-sectional study was carried out in 47 middle-aged men. In this study, plasma concentrations of different in vivo OHFAs were compared with other indices of lipid peroxidation. Under mild oxidation conditions (heparin plasma containing 4.2 or 8.3 mM AAPH), concentrations of all the measured OHFAs (8, 9, 10, 11, 12, 13, 15 and 16-OH acids) increased in an identical manner, but under highly oxidative conditions (heparin plasma containing 83 mM AAPH or 4.2 to 8.3 mM CuSO4) mainly 9 and 13-OHFAs were formed. In the cross-sectional study, plasma 11 and 13-OHFA levels were associated statistically significantly with plasma free F2alpha-isoprostanes, recognized index of in vivo lipid peroxidation (r = 0.305, p = 0.037 and r = 0.308, p = 0.035, respectively). In addition, 16-OHFA levels correlated with the ratio of electronegatively charged LDL to total LDL (r = 0.335, p = 0.021). With respect to the other OHFAs, 15-OHFA had no correlation with either other OHFAs or the reference substances used. In addition, occasionally there were contamination problems in the assessment of 12-OHFA. It is concluded that all of the measured C18 OHFAs can be used as indicators of plasma lipid peroxidation under mild oxidation conditions, though the 12 and 15-OHFAs may need to be used with some caution. Under high oxidation conditions, 9-and 13-OHFAs seem to be the most useful indices because of their high formation capacity.

Systematic review: association of low-density lipoprotein subfractions with cardiovascular outcomes

BACKGROUND

Measures of low-density lipoprotein (LDL) subfractions have been proposed as an independent risk factor for cardiovascular disease.

PURPOSE

To review published studies that reported relationships between LDL subfractions and cardiovascular outcomes.

DATA SOURCES

MEDLINE (1950 to 5 January 2009), CAB Abstracts (1973 to 30 June 2008), and Cochrane Central Register of Controlled Trials (2nd quarter of 2008), limited to English-language studies.

STUDY SELECTION

3 reviewers selected longitudinal studies with 10 or more participants that reported an association between LDL subfractions and incidence or severity of cardiovascular disease and in which plasma samples were collected before outcome determination.

DATA EXTRACTION

Data were extracted from 24 studies. The 10 studies that used analytical methods available for clinical use (all of which used nuclear magnetic resonance) had full data extraction, including quality assessment (good, fair, or poor). All studies were extracted by 1 researcher and verified by another.

DATA SYNTHESIS

All 24 studies, and the subset of 10 nuclear magnetic resonance studies, were heterogeneous in terms of the specific tests analyzed, analytical methods used, participants investigated, and outcomes measured. Higher LDL particle number was consistently associated with increased risk for cardiovascular disease, independent of other lipid measurements. Other LDL subfractions were generally not associated with cardiovascular disease after adjustment for cholesterol concentrations. No study evaluated the incremental value of LDL subfractions beyond traditional cardiovascular risk factors or their test performance.

LIMITATION

Publication bias was a possibility.

CONCLUSION

Higher LDL particle number has been associated with cardiovascular disease incidence, but studies have not determined whether any measures of LDL subfractions add incremental benefit to traditional risk factor assessment. Routine use of clinically available LDL subfraction tests to estimate cardiovascular disease risk is premature.

Stearoyl-CoA desaturase and its relation to high-carbohydrate diets and obesity

Obesity is currently a worldwide epidemic and public health burden that increases the risk for developing insulin resistance and several chronic diseases such as diabetes, cardiovascular diseases and non-alcoholic fatty liver disease. The multifactorial causes of obesity include several genetic, dietary and lifestyle variables that together result in an imbalance between energy intake and energy expenditure. Dietary approaches to limit fat intake are commonly prescribed to achieve the hypocaloric conditions necessary for weight loss. But dietary fat restriction is often accompanied by increased carbohydrate intake, which can dramatically increase endogenous fatty acid synthesis depending upon carbohydrate composition. Since both dietary and endogenously synthesized fatty acids contribute to the whole-body fatty acid pool, obesity can therefore result from excessive fat or carbohydrate consumption. Stearoyl-Coenzyme A desaturase-1 (SCD1) is a delta-9 fatty acid desaturase that converts saturated fatty acids into monounsaturated fatty acids (MUFA) and this activity is elevated by dietary carbohydrate. Mice lacking Scd1 are protected from obesity and insulin resistance and are characterized by decreased fatty acid synthesis and increased fatty acid oxidation. In this review, we address the association of high-carbohydrate diets with increased SCD activity and summarize the current literature on the subject of SCD1 and body weight regulation.

Comparability of methods for LDL subfraction determination: A systematic review

Identifying and aggressively treating individuals at elevated risk of developing cardiovascular disease (CVD) is critical to optimizing health outcomes. The CVD risk factors defined by the National Cholesterol Education Program do not fully predict individuals at high risk of developing CVD. Validation of potential methodologies against a reference method is essential to the adoption of a potential new risk factor to improve risk prediction. Low-density lipoprotein (LDL) subfraction has been advanced as a potential additional CVD risk factor. Currently, there is no reference method for determining LDL subfractions or standardizing the different methods used to measure LDL subfractions. We conducted a systematic review to identify reports comparing two or more methods of measuring LDL subfractions. Nine articles were identified that separated and quantified LDL subfractions by at least two methods. Comparative data were available for nuclear magnetic resonance vs. gel electrophoresis (GE), LipoPrint vs. other GE methods, ultracentrifugation vs. GE, and high performance gel filtration chromatography vs. GE. We found a wide range of agreement (from 7 to 94% concordance for classifying LDL patterns) among methods for LDL subfraction determinations. Different criteria and definitions were used among the articles to classify individuals with respect to CVD risk. No study used CVD or other clinical outcomes as an outcome measure. In summary, the currently available literature does not provide adequate data about comparability in terms of test performance to choose one or another method to serve as a standard nor are data on comparability in terms of predicting CVD outcomes.

Do trans fatty acids from industrially produced sources and from natural sources have the same effect on cardiovascular disease risk factors in healthy subjects? Results of the trans Fatty Acids Collaboration (TRANSFACT) study

BACKGROUND

The consumption of monounsaturated trans fatty acids (TFAs) increases the risk of cardiovascular disease (CVD). Putative differences between the effects of TFAs from industrially produced and natural sources on CVD risk markers were not previously investigated in healthy subjects.

OBJECTIVE

We aimed to compare the effects of TFAs from industrially produced and natural sources on HDL and LDL cholesterol, lipoprotein particle size and distribution, apolipoproteins, and other lipids in healthy subjects.

DESIGN

In a randomized, double-blind, controlled, crossover design, 46 healthy subjects (22 men and 24 women) consumed food items containing TFAs (11-12 g/d, representing approximately 5% of daily energy) from the 2 sources.

RESULTS

Forty subjects (19 men and 21 women) completed the study. Compared with TFAs from industrially produced sources, TFAs from natural sources significantly (P = 0.012) increased HDL cholesterol in women but not in men. Significant (P = 0.001) increases in LDL-cholesterol concentrations were observed in women, but not in men, after the consumption of TFAs from natural sources. Apolipoprotein (apo)B and apoA1 concentrations confirmed the changes observed in LDL and HDL cholesterol. Analysis of lipoprotein subclass showed that only large HDL and LDL concentrations were modified by TFAs from natural sources but not by those from industrially produced sources.

CONCLUSIONS

This study shows that TFAs from industrially produced and from natural sources have different effects on CVD risk factors in women. The HDL cholesterol-lowering property of TFAs seems to be specific to industrial sources. However, it is difficult in the present study to draw a conclusion about the effect of TFAs from either source on absolute CVD risk in these normolipidemic subjects. The mechanism underlying the observed sex- and isomer-specific effects warrants further investigation.

Nutrition in the genomics era: cardiovascular disease risk and the Mediterranean diet

The effect of dietary changes on phenotypes (i.e., plasma lipid measures, body weight and blood pressure) differs significantly between individuals. This phenomenon has been more extensively researched in relation to changes in dietary fat and plasma lipid concentrations for the prevention of cardiovascular disease (CVD) compared to other pathological conditions. Although common knowledge associates low fat diets with reductions in total and plasma LDL cholesterol, the clinical evidence shows dramatic inter-individual differences in response that are partially due to genetic factors. The discovery of the cardioprotective and other healthy properties of the Mediterranean diet has popularized the consumption of Mediterranean products such as olive oil. Molecular, clinical, and epidemiological studies have begun to shed some light about how various components of this diet may protect the cardiovascular system and to decrease the risk of other diseases such as cancer. However, it is also possible that the right combination of genetic, cultural, socioeconomic factors is needed to achieve full benefit. It has been proposed that the Mediterranean diet may be closer to the ancestral foods that were part of human development and our metabolism may have evolved to work optimally on such a diet rather than with the current diets richer in saturated fat and highly refined and processed foods. Therefore, it is possible that alleles that are associated with increase disease risk may be silenced in the presence of that more ancestral and traditional diet and lifestyle. This knowledge may provide the basis for successful public health as well individual approaches for disease prevention.

Influences of the phosphatidylcholine transfer protein gene variants on the LDL peak particle size

BACKGROUND

The small, dense LDL phenotype is associated with an increased cardiovascular disease risk. A genome-wide scan performed on 236 nuclear families of the Quebec Family Study (QFS) revealed a quantitative trait locus (QTL) affecting LDL peak particle size (LDL-PPD) and density on the 17q21 region. This region contains the phosphatidylcholine transfer protein gene (PCTP). In the liver, phosphatidylcholine transfer protein binds specifically phosphatidylcholine suggesting a role for this protein in the formation of HDL and possibly VLDL phospholipid membranes.

OBJECTIVES

To test the association between two coding polymorphisms (c.29A>C (Glu10Ala) and c.188G>A (Cys63Tyr)) in PCTP gene and the LDL-PPD.

METHODS

LDL-PPD was measured by non-denaturating 2-16% polyacrylamide gradient gel electrophoresis on 623 QFS subjects.

RESULTS

After adjustment for age and sex, carriers of the c.29C allele showed larger LDL-PPD than A/A homozygotes (p<0.05). These results remained significant when LDL-PPD was further adjusted for the effects of BMI and triglyceride levels (p<0.04). We also observed a three-fold lower risk of having the small (LDL-PPD <256A), dense LDL phenotype in subjects carrying the c.29C allele, when compared to A/A homozygotes (OR=0.35 (95% CI: 0.14-0.91; p=0.03)).

CONCLUSION

PCTP gene variants are associated with LDL-PPD.

State of the Art Reviews: Relationship Between Diet/ Physical Activity and Health

Obesity and 4 of the leading causes of death—heart disease, cancer, stroke, and type 2 diabetes mellitus—are related to lifestyle. The combination of a healthy weight, prudent diet, and daily physical activity clearly plays a role in primary, secondary, and tertiary prevention of these and other chronic diseases. Because nearly 65% of the adult population is overweight or obese, weight loss and maintenance are central to this review article. Improved lipid profiles, blood pressure, insulin sensitivity, and euglycemia are associated with weight loss or a normal body weight; thus, maintaining a healthy weight is a universal recommendation for health. The methods for improving lifestyle described in the section on obesity include assessing nutritional status and stages of change of the client, setting realistic goals, eating a diet high in fruits and vegetables with low-fat sources of dairy and protein, and achieving appropriate physical activity levels. The importance of physicians discussing weight with clients and vice versa is stressed. The common features of lifestyle-related diseases make them amenable to similar lifestyle interventions.

Particle size of LDL is affected by the National Cholesterol Education Program (NCEP) step II diet in dyslipidaemic adolescents

The objective was to determine the effects of the National Cholesterol Education Program (NCEP) step II diet on LDL and HDL particle size in dyslipidaemic adolescents. Forty-four dyslipidaemic adolescents, aged 10–18 years, participated in this case-control study. The control diet was a diet similar to what most Tehranian adolescents eat. NCEP step II diet was a diet with 30 % of energy as total fat, less than 7 % saturated fat, less than 200 mg cholesterol/d, less than 15 % of energy as MUFA and less than 10 % as PUFA. Lipoprotein particle size was the major outcome variable, which was measured after 3 months of intervention. Comparison was made by the repeated measurement ANOVA. The mean BMI was 26·3 (sd4·2) kg/m2. There were no significant changes in weight or physical activity in the two groups during the study. The NCEP diet resulted in higher reduction in total cholesterol ( − 13 (sd4)v.− 2 (sd0·3) mg/dl,P < 0·001) and LDL ( − 9 (sd2)v.3 (sd0·6) mg/dl,P < 0·01), and higher increase in size of the LDL (1·7 (sd0·4)v.0·1 (sd0·4) nanometer,P < 0·001). HDL particle size did not change significantly. NCEP step II diet had a favourable effect on the LDL particle size. The related mechanism needs to be studied in future experimental designs.

Clinical importance and therapeutic modulation of small dense low-density lipoprotein particles

The National Cholesterol Education Programme Adult Treatment Panel III accepted the predominance of small dense low-density lipoprotein (sdLDL) as an emerging cardiovascular disease (CVD) risk factor. Most studies suggest that measuring low-density lipoprotein (LDL) particle size, sdLDL cholesterol content and LDL particle number provides additional assessment of CVD risk. Therapeutic modulation of small LDL size, number and distribution may decrease CVD risk; however, no definitive causal relationship is established, probably due to the close association between sdLDL and triglycerides and other risk factors (e.g., high-density lipoprotein, insulin resistance and diabetes). This review addresses the formation and measurement of sdLDL, as well as the relationship between sdLDL particles and CVD. The effect of hypolipidaemic (statins, fibrates and ezetimibe) and hypoglycaemic (glitazones) agents on LDL size and distribution is also discussed.

Nutrigenetics, plasma lipids, and cardiovascular risk

Cardiovascular disease (CVD) results from complex interactions between genetic and environmental factors. The evidence supports that gene-environment interactions modulate plasma lipid concentrations and potentially CVD risk. Several genes (eg, apolipoprotein A-I and A-IV, apolipoprotein E, and hepatic lipase) are providing proof-of-concept for the application of genetics in the context of personalized nutrition for CVD prevention. The spectrum of candidate genes has been expanding to incorporate those involved in intracellular lipid metabolism and especially those transcription factors (ie, peroxisome proliferator activator receptors) that act as sensors of nutrients in the cell (eg, polyunsaturated fatty acids) to trigger metabolic responses through activation of specific sets of genes. However, current knowledge is still very limited and so is the potential benefit of its application to clinical practice. Thinking needs to evolve from simple scenarios (eg, one single dietary component, a single nucleotide polymorphism and risk factor) to more realistic situations involving multiple interactions. One of the first situations where personalized nutrition is likely to be beneficial is in patients with dyslipidemia who require special intervention with dietary treatment. This process could be more efficient if the recommendations were carried out based on genetic and molecular knowledge. Moreover, adherence to dietary advice may increase when it is supported with information based on nutritional genomics, and a patient believes the advice is personalized. However, a number of important changes in the provision of health care are needed to achieve the potential benefits associated with this concept, including a teamwork approach with greater integration among physicians, food and nutrition professionals, and genetic counselors.

Composition, structure and absorption of milk lipids: a source of energy, fat-soluble nutrients and bioactive molecules

Milkfat is a remarkable source of energy, fat-soluble nutrients and bioactive lipids for mammals. The composition and content of lipids in milkfat vary widely among mammalian species. Milkfat is not only a source of bioactive lipid components, it also serves as an important delivery medium for nutrients, including the fat-soluble vitamins. Bioactive lipids in milk include triacylglycerides, diacylglycerides, saturated and polyunsaturated fatty acids, and phospholipids. Beneficial activities of milk lipids include anticancer, antimicrobial, anti-inflammatory, and immunosuppression properties. The major mammalian milk that is consumed by humans as a food commodity is that from bovine whose milkfat composition is distinct due to their diet and the presence of a rumen. As a result of these factors bovine milkfat is lower in polyunsaturated fatty acids and higher in saturated fatty acids than human milk, and the consequences of these differences are still being researched. The physical properties of bovine milkfat that result from its composition including its plasticity, make it a highly desirable commodity (butter) and food ingredient. Among the 12 major milk fatty acids, only three (lauric, myristic, and palmitic) have been associated with raising total cholesterol levels in plasma, but their individual effects are variable-both towards raising low-density lipoproteins and raising the level of beneficial high-density lipoproteins. The cholesterol-modifying response of individuals to consuming saturated fats is also variable, and therefore the composition, functions and biological properties of milkfat will need to be re-evaluated as the food marketplace moves increasingly towards more personalized diets.

Microsomal triglyceride transfer protein -493T variant reduces IDL plus LDL apoB production and the plasma concentration of large LDL particles

The microsomal triglyceride transfer protein (MTP) is essential for the synthesis and secretion of apolipoprotein B (apoB)-containing lipoproteins. We investigated the role the MTP -493G/T gene polymorphism in determining the apoB-100 secretion pattern and LDL heterogeneity in healthy human subjects. Groups of carriers of the T and the G variants (n = 6 each) were recruited from a cohort of healthy 50-yr-old men. Kinetic studies were performed by endogenous [(2)H(3)]leucine labeling of apoB and subsequent quantification of the stable isotope incorporation. apoB production rates, metabolic conversions, and eliminations were calculated by multicompartmental modeling (SAAM-II). LDL subfraction distribution was analyzed in the entire cohort (n = 377). Carriers of the MTP -493T allele had lower plasma LDL apoB and lower concentration of large LDL particles [LDL-I: 136 +/- 57 (TT) vs. 175 +/- 55 (GG) mg/l, P < 0.01]. Kinetic modeling suggested that MTP -493T homozygotes had a 60% lower direct production rate of intermediate-density lipoprotein (IDL) plus LDL compared with homozygotes for the G allele (P < 0.05). No differences were seen in production rates of large and small VLDL, nor were there any differences in metabolic conversion or elimination rates of apoB between the genotype groups. This study shows that a polymorphism in the MTP gene affects the spectrum of endogenous apoB-containing lipoprotein particles produced in humans. Reduced direct production of LDL plus IDL appears to be related to lower plasma concentrations of large LDL particles.

Managing abnormal blood lipids: a collaborative approach

Current data and guidelines recommend treating abnormal blood lipids (ABL) to goal. This is a complex process and requires involvement from various healthcare professionals with a wide range of expertise. The model of a multidisciplinary case management approach for patients with ABL is well documented and described. This collaborative approach encompasses primary and secondary prevention across the lifespan, incorporates nutritional and exercise management as a significant component, defines the importance and indications for pharmacological therapy, and emphasizes the importance of adherence. Use of this collaborative approach for the treatment of ABL ultimately will improve cardiovascular and cerebrovascular morbidity and mortality.

Genetic variation and lipid metabolism: modulation by dietary factors

Cardiovascular diseases (CVD) result from complex interactions between genetic and environmental factors. The evidence supports that gene-environment interactions modulate plasma lipid concentrations and potentially CVD risk. The findings from studies examining gene-diet interactions and lipid metabolism have been promising. Several loci (eg, APOA1, APOE, LIPC) are providing proof of concept for the application of genetics in the context of personalized nutrition for CVD prevention. The spectrum of candidate genes has been expanding to incorporate those involved in intracellular lipid metabolism (eg, iPPARs, CYP7A1). However, the practical application of these findings is not ready for prime time. There is a compelling need for replication using a higher level of scientific evidence. Moreover, we need to evolve from the simple scenarios examined nowadays (ie, one single dietary component, SNP, and risk factor) to more realistic situations involving multiple interactions. In summary, there is need for both large population studies and well-standardized intervention studies.

Detection of a major gene effect for LDL peak particle diameter and association with apolipoprotein H gene haplotype

Low-density lipoprotein (LDL) size, a coronary heart disease risk factor, is influenced by both genetic and environmental factors. Results from the Quebec Family Study (QFS) revealed that the LDL peak particle diameter (LDL-PPD) aggregates in families with a heritability coefficient above 50% and is affected by a major quantitative trait locus on chromosome 17q (LOD=6.8). Complex segregation analyses have consistently demonstrated a major gene effect influencing LDL size. In the present study, we report a similar analysis in the QFS cohort, which suggests that a major gene explains 23% of the variance in age-body mass index and triglyceride-adjusted LDL-PPD. The most intuitive positional candidate gene on chromosome 17q is the apolipoprotein H gene. Direct sequencing of the promoter, coding regions, and exon-intron splicing boundaries of this gene revealed the presence of three missense mutations and two polymorphisms in the untranslated regions. Using family-based association tests, none of these variants was individually associated with LDL-PPD. However, analysis of the haplotypes constructed from the three missense mutations, suggested that one particular haplotype (frequency=20.9%) was associated with a significant increase in LDL-PPD trait values (p=0.046). Taken together, these results suggest the presence of a major gene effect influencing LDL-PPD and a positive association with a positional candidate gene located on chromosome 17q. Replication of the association between apolipoprotein H gene haplotype and LDL-PPD is required before reaching firm conclusion.

Influence of dietary carbohydrate and fat on LDL and HDL particle distributions

Variations in the size and density distributions of low-density lipoprotein (LDL) and high-density lipoprotein (HDL) particles have been related to risk for cardiovascular disease. In particular, increased levels of small, dense LDL particles, together with reduced levels of large HDL and increases in small HDL, are integral features of the atherogenic dyslipidemia found in patients with insulin resistance, obesity, and metabolic syndrome. Increased dietary carbohydrates, particularly simple sugars and starches with high glycemic index, can increase levels of small, dense LDL and HDL, primarily by mechanisms that involve increasing plasma triglyceride concentrations. Low-carbohydrate diets may have the opposite effects. Diets with differing fatty acid composition can also influence LDL and HDL particle distributions.

SINGLE NUCLEOTIDE POLYMORPHISMS THAT INFLUENCE LIPID METABOLISM: Interaction with Dietary Factors

Cardiovascular disease (CVD) risk is the result of complex interactions between genetic and environmental factors. During the past few decades, much attention has focused on plasma lipoproteins as CVD risk factors. The current evidence supports the concept that gene-environment interactions modulate plasma lipid concentrations and potentially CVD risk. The findings from studies examining gene-diet interactions and lipid metabolism have been highly promising. Several loci (i.e., APOA1, APOA4, APOE, and LIPC) are providing proof-of-concept for the potential application of genetics in the context of personalized nutritional recommendations for CVD prevention. However, the incorporation of these findings to the clinical environment is not ready for prime time. There is a compelling need for replication using a higher level of scientific evidence. Moreover, we need to evolve from the simple scenarios examined nowadays (i.e., one single dietary component, single nucleotide polymorphism, and risk factor) to more realistic situations involving interactions between multiple genes, dietary components, and risk factors. In summary, there is need for both large population studies and well-standardized intervention studies.

Insulin resistance, LDL particle size, and LDL susceptibility to oxidation in pediatric kidney and liver recipients

BACKGROUND

Dyslipidemia is common after solid organ transplantation. We have described hypertriglyceridemia in about 50% of our pediatric kidney, and in about 30% of our liver recipients. The aim of the present study was to find out whether this post-transplantation hypertriglyceridemia after pediatric solid organ transplantation is associated with insulin resistance and the occurrence of small, dense low-density lipoprotein (LDL).

METHODS

Fifty kidney and 25 liver recipients (aged 4 to 18 years) on triple immunosuppression, and 181 control children participated in the study for an average of 5.3 and 6.4 years after kidney and liver transplantation (range 1 to 11 years), respectively. Homeostasis model assessments for insulin resistance (HOMA) were calculated and fasting lipoprotein lipid profile, apolipoprotein A-I and B concentrations, LDL particle diameter, and indices of LDL susceptibility to copper-induced oxidation determined.

RESULTS

Kidney patients had significantly higher serum total, high-density, and low-density lipoprotein cholesterol, triglyceride, apolipoprotein A-I and B concentrations than liver patients or control subjects (P < 0.003 for all). HOMA indices higher than the 95th percentile of Canadian normal children were seen in 50.0% of kidney (of liver 41.2%) recipients younger than 11 years, and in 27.3% of older recipients (of liver 37.5%). Smaller sized LDL or LDL of increased oxidizability was not more frequent in patients than in control children.

CONCLUSION

Pediatric kidney recipients had significantly higher lipid and insulin concentrations than healthy control children. Combined hyperlipidemia and features of the dysmetabolic syndrome were common in children after kidney and liver transplantation. However, no small, dense LDL, or LDL prone to oxidation was seen in either group.

Unveiling Health Attitudes and Creating Good-For-You Foods: The Genomics Metaphor, Consumer Innovative Web-Based Technologies

This article presents an integrated analysis of three emerging knowledge bases in the nutrition and consumer products industries, and how they may effect the food industry. These knowledge bases produce new vistas for corporate product development, especially with respect to those foods that are positioned as 'good for you.' Couched within the current thinking of state-of-the-art knowledge and information, this article highlights how today's thinking about accelerated product development can be introduced into the food and health industries to complement these three research areas. The 3 knowledge bases are: the genomics revolution, which has opened new insights into understanding the interactions of personal needs of individual consumers with nutritionally relevant components of the foods; the investigation of food choice by scientific studies; the development of large scale databases (mega-studies) about the consumer mind. These knowledge bases, combined with new methods to understand the consumer through research, make possible a more focused development. The confluence of trends outlined in this article provides the corporation with the beginnings of a new path to a knowledge-based, principles-grounded product-development system. The approaches hold the potential to create foods based upon people's nutritional requirements combined with their individual preferences. Integrating these emerging knowledge areas with new consumer research techniques may well reshape how the food industry develops new products to satisfy consumer needs and wants.

Diet and low-density lipoprotein particle size

Small, dense low-density lipoprotein (LDL) particles are being increasingly recognized as an important risk factor for cardiovascular disease. This paper provides an overview of how different diets and macronutrients modulate the LDL size phenotype. Data reviewed indicated that several components of the LDL size phenotype should be measured concurrently in order to fully appreciate the impact of diet on this complex trait. Data also suggested that numerous dietary elements have a significant impact on several characteristics of the LDL size phenotype, thus providing further evidence to the concept that specific dietary modifications can beneficially alter cardiovascular disease risk beyond their known and demonstrated effects on plasma LDL cholesterol concentrations.

Metabolic and health effects of isomeric fatty acids

PURPOSE OF REVIEW

Isomeric fatty acids have the same number of carbon and hydrogen atoms, but may have distinct metabolic and health effects. Two well-known examples of isomeric fatty acids are cis and trans monounsaturated fatty acids, and conjugated isomers of linoleic acid (CLA). The purpose of this review is to summarize recent findings from human studies on the metabolic and health effects of these two classes of isomeric fatty acids.

RECENT FINDINGS

Apart from an unfavorable effect on serum lipoproteins, trans monounsaturated fatty acids from hydrogenated oils may increase plasma markers for a low-grade inflammatory state. From epidemiological studies, however, it is not possible to conclude if effects of ruminant and industrial trans fatty acids on cardiovascular risk are different. In contrast to in-vitro and animal studies, there are no indications that in humans the two most common CLA isomers (cis9,trans11-CLA and trans10,cis12-CLA) affect body composition differently. Longer-term supplementation, however, may slightly decrease body fat mass without apparent effects on plasma markers for glucose and lipid metabolism. Other studies have even reported adverse effects of CLA supplementation on insulin resistance and lipid peroxidation.

SUMMARY

Evidence is increasing that trans monounsaturated fatty acids from hydrogenated oils increase plasma markers of low-grade chronic inflammation. From epidemiological studies, however, it is not clear if effects of ruminant and industrial trans fatty acids on cardiovascular risk are different. Effects of CLA on body composition remain controversial and more research is needed before the widely available CLA supplements should be advocated as an adjunct to control body weight.

Relationship between low-density lipoprotein subclasses and asymptomatic atherosclerosis in subjects from the Atherosclerosis Risk in Communities (ARIC) Study

Low-density lipoprotein (LDL) particle size has been associated with coronary heart disease, but an association between LDL size and preclinical atherosclerosis is less well established. Using gradient gel electrophoresis, large (A), intermediate (I) and small (B) LDL size subclasses were determined in 198 cases with asymptomatic carotid artery atherosclerosis (determined by B-mode ultrasonography) and 318 controls from the Atherosclerosis Risk in Communities (ARIC) Study. In Caucasians, a smaller LDL size was more prevalent in men and associated with a higher body mass index, hypertension prevalence, and plasma total- and LDL-cholesterol and triglycerides, but lower HDL-cholesterol. In African-Americans, a smaller LDL size was associated with higher triglycerides and lower HDL-cholesterol and hypertension prevalence. In Caucasians, Subclass B prevalence was 29.1% among cases and 14.8% among controls. The odds ratio (95% confidence interval) for Subclass B rather than Subclass A in Caucasian cases was 2.94 (1.67-5.17); the association remained significant after controlling for age, body mass index, smoking, and either plasma triglycerides or HDL-cholesterol. In African-Americans, however, there was no significant association between LDL subclass and case status. A predominance of smaller LDL particles is associated with asymptomatic carotid artery atherosclerosis in Caucasians, through mechanisms that remain to be elucidated.