Postprandial chylomicrons and VLDLs in severe hypertriacylglycerolemia are lowered more effectively than are chylomicron remnants after treatment with n-3 fatty acids

Effect of Dietary Flaxseed Oil Supplementation on the Redox Status, Haematological and Biochemical Parameters of Horses' Blood

Simple Summary

Flaxseed oils have long been used in animal feeding and human nutrition due to the beneficial effects of their biologically active substances, especially omega-3 polyunsaturated fatty acids (PUFA). This study aimed to evaluate the effect of the replacement of soybean oil (SO) with flaxseed oil (FO) in the horses’ diet on biochemical, haematological, and redox status parameters of the blood. We found FO contributed to an improvement of lipid profile, haematological parameters of the blood and enhanced antioxidant defence mechanisms of horses. This suggests that substitution of SO with FO in the diet of horses is beneficial for their health status.

Abstract

This study compared the effect of two dietary vegetable oils on plasma biochemical indices, haematological parameters, and redox status of horses. Forty riding horses (20 mares and 20 stallions) of the Malopolski breed were divided equally into two groups that were similar in terms of age, sex, and body weight (on average 530 ± 30 kg). The horses received soybean oil (SO) or flaxseed oil (FO) in the amount of 25 mL per 100 kg BW/day. After 60 days, blood was collected for biochemical and haematological analyses. The results show that horses receiving FO as compared to the SO group had significantly lower plasma levels of glucose, low density lipoprotein cholesterol, total cholesterol/high-density lipoprotein (HDL) ratio and triacylglycerols, as well as the activities of alanine aminotransferase and alkaline phosphatase. In turn, %HDL-TC and lactate dehydrogenase activity were significantly higher in the FO group. The inclusion of FO in the diet contributed to an increase in antioxidant indices: creatinine, vitamin C, copper, and zinc contents and also superoxide dismutase and catalase activities. The level of the end product of lipid peroxidation, i.e., malonyl dialdehyde, in the FO group as compared to the SO group was significantly lower. Moreover, FO caused an elevation in red blood cell indicators, lymphocyte count and lysozymes. In conclusion, FO exerts a beneficial effect by stimulating antioxidant defence mechanisms of horses and reducing the severity of oxidative stress. FO also improved the lipid profile and haematological parameters of the blood. The replacement of SO by FO is recommended based on these findings.

Effect of Nutrient and Micronutrient Intake on Chylomicron Production and Postprandial Lipemia

Postprandial lipemia, which is one of the main characteristics of the atherogenic dyslipidemia with fasting plasma hypertriglyceridemia, low high-density lipoprotein cholesterol and an increase of small and dense low-density lipoproteins is now considered a causal risk factor for atherosclerotic cardiovascular disease and all-cause mortality. Postprandial lipemia, which is mainly related to the increase in chylomicron production, is frequently elevated in individuals at high cardiovascular risk such as obese or overweight patients, type 2 diabetic patients and subjects with a metabolic syndrome who share an insulin resistant state. It is now well known that chylomicron production and thus postprandial lipemia is highly regulated by many factors such as endogenous factors: circulating factors such as hormones or free fatty acids, genetic variants, circadian rhythms, or exogenous factors: food components, dietary supplements and prescription drugs. In this review, we focused on the effect of nutrients, micronutrients and phytochemicals but also on food structure on chylomicron production and postprandial lipemia.

Effect of omega-3 fatty acid plus vitamin E Co-Supplementation on lipid profile: A systematic review and meta-analysis

BACKGROUND

Dyslipidemia is linked to chronic inflammation, which in return leads to a set of chronic disorders. Omega-3 fatty acids have been reported to reduce inflammation. Furthermore, Vitamin E is a fat-soluble vitamin which has antioxidant and anti-inflammatory effects. Vitamin E and omega-3 fatty acids co-supplementations may be more effective than the single supplementation in control dyslipidemia. Therefore, we designed and conducted the current systematic review and meta-analysis to investigate the effect of co-supplementation of vitamin E and omega-3 fatty acids on the lipid profile.

METHODS

A comprehensive search for studies published between January 1990 and July 2018 was performed. The initial search extracted 3015 potentially relevant articles. After studying these publications, 9 RCTs were potentially eligible and retrieved in full text.

RESULTS

The meta-analysis indicate that on total cholesterol, HDL, LDL and triglyceride individually did not show any significant difference between intervention and control groups, but vitamin E an omega-3 fatty acids co-supplementations significantly reduce VLDL levels.

CONCLUSIONS

Based on the available evidence, omega-3 fatty acid and vitamin E co-supplementation can reduce VLDL, although its effect on other lipid profile parameters requires more well-designed studies.

Platycodi radix beverage ameliorates postprandial lipemia response through lipid clearance of triglyceride-rich lipoprotein: A randomized controlled study in healthy subjects with a high-fat load

BACKGROUND/OBJECTIVES

Elevation of postprandial lipemia characterized by a rise in triglyceride (TG)-rich lipoproteins can increase the risk of atherogenesis. The objective of this study was to investigate postprandial lipemia response to a single dietary fat/sugar load test and monitor beneficial changes induced by the consumption of Platycodi radix (AP) beverage in healthy subjects.

SUBJECTS/METHODS

A total of 52 subjects were randomly assigned to either placebo or AP beverage group with a high-fat shake in a randomized controlled crossover trial. Postprandial blood was collected at 0, 1, 2, 4, and 6 h and analyzed for TG and lipoprotein lipase mass. Inhibition of pancreatic lipase was determined in vitro.

RESULTS

AP inhibited pancreatic lipase activity in vitro (IC₅₀ = 5 mg/mL). Compared to placebo beverage, AP beverage consumption with a high-fat shake induced significant increase of plasma lipoprotein lipase mass (P = 0.0111, β estimate = 4.2948) with significant reduction in very low-density lipoprotein (VLDL) TG concentration (P = 0.038, β estimate = −52.69) at 6 h. Based on significant correlation between high-fat dietary scores MEDFICTS and postprandial TG responses in VLDL (P = 0.0395, r = 0.2127), subgroup analysis revealed that 6 h-postprandial VLDL TG response was significantly decreased by AP consumption in subjects with MEDFICTS ≥ 40 (P = 0.0291, β estimate = −7214).

CONCLUSIONS

AP beverage might have potential to alleviate postprandial lipemia through inhibiting pancreatic lipase activity and elevating lipoprotein lipase mass. Subgroup analysis revealed that subjects with high-fat dietary pattern could be classified as responders to AP beverage among all subjects.

Elevation of Low-Density Lipoprotein Cholesterol Concentration with Over-the-Counter Fish Oil Supplementation

Objective:

To report a case of elevated low-density lipoprotein cholesterol (LDL-C) concentration in a patient taking fish oil supplements for hypertriglyceridemia.

Case Summary:

A 63-year-old white woman had been taking 2.7 g of eico-sapentaenotc acid (EPA) and docosahexaenoic acid (DHA) daily in 9 g of over-the-counter (OTC) fish oil capsules for triglyceride lowering. Prior to the adverse event, she had baseline fasting triglyceride (TG) and LDL-C concentrations of 278 mg/dL and 106 mg/dL, respectively. After 6 weeks of treatment with fish oil, fasting TG levels decreased by 47.5% (-132 mg/dL) and the LDL-C increased by 75% (+80 mg/dL). Discontinuation of therapy for 6 weeks resulted in TG returning to high concentrations (334 mg/dL; +56 mg/dL change from baseline) and LDL-C decreasing toward baseline (143 mg/dL; +37 mg/dL change from baseline).

Discussion:

Fish oil, an omega-3 polyunsaturated fatty acid, consists of EPA and DHA. EPA and DHA are thought to inhibit the synthesis of triglycerides in the liver. Type IV dyslipidemic patients may develop increased LDL-C levels while taking fish oil to lower triglycerides due to possible down-regulation of the LDL-C receptor in hepatic cells and formation of larger LDL particles. Use of the Naranjo probability scale indicates a probable relationship between elevations in LDL-C from baseline and initiation of fish oil treatment for hypertriglyceridemia. It is unknown whether any component within this particular product could have contributed to such an unusual elevation in LDL-C.

Conclusions:

This case documents a much higher LDL-C elevation associated with OTC fish oil supplementation than has been previously identified in the literature. Healthcare providers should be advised that LDL-C levels may increase with use of OTC fish oil and should monitor patients periodically for such elevations. The significance of this Increase on clinical outcomes is not known.

Postprandial Dysmetabolism and Oxidative Stress in Type 2 Diabetes: Pathogenetic Mechanisms and Therapeutic Strategies

Postprandial dysmetabolism in type 2 diabetes (T2D) is known to impact the progression and evolution of this complex disease process. However, the underlying pathogenetic mechanisms still require full elucidation to provide guidance for disease prevention and treatment. This review focuses on the marked redox changes and inflammatory stimuli provoked by the spike in blood glucose and lipids in T2D individuals after meals. All the causes of exacerbated postprandial oxidative stress in T2D were analyzed, also considering the consequence of enhanced inflammation on vascular damage. Based on this in-depth analysis, current strategies of prevention and pharmacologic management of T2D were critically reexamined with particular emphasis on their potential redox-related rationale.

α-Lipoic acid as a triglyceride-lowering nutraceutical

Considering the current obesity epidemic in the United States (>100 million adults are overweight or obese), the prevalence of hypertriglyceridemia is likely to grow beyond present statistics of ∼30% of the population. Conventional therapies for managing hypertriglyceridemia include lifestyle modifications such as diet and exercise, pharmacological approaches, and nutritional supplements. It is critically important to identify new strategies that would be safe and effective in lowering hypertriglyceridemia. α-Lipoic acid (LA) is a naturally occurring enzyme cofactor found in the human body in small quantities. A growing body of evidence indicates a role of LA in ameliorating metabolic dysfunction and lipid anomalies primarily in animals. Limited human studies suggest LA is most efficacious in situations where blood triglycerides are markedly elevated. LA is commercially available as dietary supplements and is clinically shown to be safe and effective against diabetic polyneuropathies. LA is described as a potent biological antioxidant, a detoxification agent, and a diabetes medicine. Given its strong safety record, LA may be a useful nutraceutical, either alone or in combination with other lipid-lowering strategies, when treating severe hypertriglyceridemia and diabetic dyslipidemia. This review examines the current evidence regarding the use of LA as a means of normalizing blood triglycerides. Also presented are the leading mechanisms of action of LA on triglyceride metabolism.

Lowering triglycerides to modify cardiovascular risk: will icosapent deliver?

Despite the clinical benefits of lowering levels of low-density lipoprotein cholesterol, many patients continue to experience cardiovascular events. This residual risk suggests that additional risk factors require aggressive modification to result in more effective prevention of cardiovascular disease. Hypertriglyceridemia has presented a considerable challenge with regard to understanding its role in the promotion of cardiovascular risk. Increasing evidence has established a clear causal role for elevated triglyceride levels in vascular risk. As a result, there is increasing interest in the development of specific therapeutic strategies that directly target hypertriglyceridemia. This has seen a resurgence in the use of omega-3 fatty acids for the therapeutic lowering of triglyceride levels. The role of these agents and other emerging strategies to reduce triglyceride levels in order to decrease vascular risk are reviewed.

Distinct regulation of plasma LDL cholesterol by eicosapentaenoic acid and docosahexaenoic acid in high fat diet-fed hamsters: participation of cholesterol ester transfer protein and LDL receptor

Despite established anti-atherogenic action, previous reports have shown that fish oils or n-3 poly-unsaturated fatty acid (PUFA) increase plasma LDL-C in animals and humans. However, which component of n-3 PUFAs and what mechanisms contribute to this increase are unclear. We investigated the effects of the major components of n-3 PUFA, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), on plasma LDL-C in high fat diet-fed hamsters. While LDL-C increased significantly with n-3 PUFA oil and DHA, EPA had no effect on LDL-C. Interestingly, a positive correlation was found between plasma cholesterol ester transfer protein (CETP) activity and LDL-C. Only DHA increased plasma CETP activity and significantly decreased LDL receptor expression in the liver. Our data suggest that DHA, not EPA, is a major factor in the LDL-C increasing effect of n-3 PUFA oil. These differential effects on LDL-C may arise from differences in plasma CETP activity and LDL receptor expression.

A short-term n-3 DPA supplementation study in humans

PURPOSE

Despite the detailed knowledge of the absorption and incorporation of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) into plasma lipids and red blood cells (RBC) in humans, very little is known about docosapentaenoic acid (DPA, 22:5 n-3). The aim of this study was to investigate the uptake and incorporation of pure DPA and EPA into human plasma and RBC lipids.

METHODS

Ten female participants received 8 g of pure DPA or pure EPA in randomized crossover double-blinded manner over a 7-day period. The placebo treatment was olive oil. Blood samples were collected at days zero, four and seven, following which the plasma and RBC were separated and used for the analysis of fatty acids.

RESULTS

Supplementation with DPA significantly increased the proportions of DPA in the plasma phospholipids (PL) (by twofold) and triacylglycerol (TAG) fractions (by 2.3-fold, day 4). DPA supplementation also significantly increased the proportions of EPA in TAG (by 3.1-fold, day 4) and cholesterol ester (CE) fractions (by 2.0-fold, day 7) and of DHA in TAG fraction (by 3.1-fold, day 4). DPA proportions in RBC PL did not change following supplementation. Supplementation with EPA significantly increased the proportion of EPA in the plasma CE and PL fractions, (both by 2.7-fold, day 4 and day 7) and in the RBC PL (by 1.9-fold, day 4 and day 7). EPA supplementation did not alter the proportions of DPA or DHA in any lipid fraction. These results showed that within day 4 of supplementation, DPA and EPA demonstrated different and specific incorporation patterns.

CONCLUSION

The results of this short-term study suggest that DPA may act as a reservoir of the major long-chain n-3 fatty acids (LC n-3 PUFA) in humans.

Physical activity and postprandial lipidemia: are energy expenditure and lipoprotein lipase activity the real modulators of the positive effect?

Historically, the link between elevated cholesterol and increased risk of cardiovascular disease has been based on fasting measurements. This is appropriate for total, low-density lipoprotein and high-density lipoprotein cholesterol. However, triglyceride concentrations vary considerably throughout the day in response to the regular consumption of food and drink. Recent findings indicate that postprandial triglyceride concentrations independently predict future cardiovascular risk. Potential modulators of postprandial lipidemia include meal composition and physical activity. Early cross sectional studies indicated that physically active individuals had a lower postprandial lipidemic response compared to inactive individuals. However, the effect of physical activity on postprandial lipidemia is an acute phenomenon, which dissipates within 60 h of a single bout of exercise. Total exercise induced energy expenditure, rather than duration or intensity of the physical activity is commonly reported to be a potent modulator of postprandial lipidemia. However, the pooled results of studies in this area suggest that energy expenditure exerts most of its influence on fasting triglyceride concentrations rather than on the incremental change in triglyceride concentrations seen following meal consumption. It seems more likely that energy expenditure is one component of a multifactorial list of mediators that may include local muscle contractile activity, and other yet to be elucidated mechanisms.

Understanding postprandial inflammation and its relationship to lifestyle behaviour and metabolic diseases

Postprandial hyperlipidemia with accumulation of remnant lipoproteins is a common metabolic disturbance associated with atherosclerosis and vascular dysfunction, particularly during chronic disease states such as obesity, the metabolic syndrome and, diabetes. Remnant lipoproteins become attached to the vascular wall, where they can penetrate intact endothelium causing foam cell formation. Postprandial remnant lipoproteins can activate circulating leukocytes, upregulate the expression of endothelial adhesion molecules, facilitate adhesion and migration of inflammatory cells into the subendothelial space, and activate the complement system. Since humans are postprandial most of the day, the continuous generation of remnants after each meal may be one of the triggers for the development of atherosclerosis. Modulation of postprandial lipemia by lifestyle changes and pharmacological interventions could result in a further decrease of cardiovascular mortality and morbidity. This paper will provide an update on current concepts concerning the relationship between postprandial lipemia, inflammation, vascular function, and therapeutic options.

Dietary intake of stearidonic acid-enriched soybean oil increases the omega-3 index: randomized, double-blind clinical study of efficacy and safety

BACKGROUND

The benefits of omega-3 (n-3) long-chain polyunsaturated fatty acids to heart health are well established. Stearidonic acid (SDA, 18:4n-3) may contribute to these benefits.

OBJECTIVE

The objective was to evaluate the ability of SDA-containing soybean oil to increase the omega-3 index [erythrocyte eicosapentaenoic acid (EPA) + docosahexaenoic acid, as a percentage of total fatty acids] and to affect other cardiovascular disease risk markers compared with EPA and regular soy oil (control).

DESIGN

This was a randomized, placebo-controlled, double-blind multicenter study in which 252 overweight subjects were randomly assigned to 1 of 3 treatments for 12 wk: 1 g encapsulated soybean oil/d plus 14.7 g liquid soybean oil/d to be mixed in food (control group), 1 g encapsulated EPA/d plus 14.7 g liquid soybean oil/d (EPA group), and 1 g encapsulated soybean oil/d plus 14.7 g liquid SDA-enriched soybean oil/d, providing 4.2 g SDA (SDA group). Subjects consumed treatment oils in exchange for other oils in their diet.

RESULTS

The mean (±SE) baseline omega-3 index was similar between treatments, but after 12 wk of treatment values for this index were 4.15 ± 0.12%, 4.84 ± 0.13%, and 4.69 ± 0.15% for control, EPA, and SDA groups, respectively. Values for the EPA and SDA groups were greater than those for control subjects in the intent-to-treat population (P < 0.001 and P = 0.006, respectively). No adverse treatment-related effects of SDA-enriched soybean oil were reported.

CONCLUSIONS

SDA-enriched soybean oil increased the omega-3 index by raising erythrocyte EPA concentrations. SDA-enriched soybean oil is a land-based n-3 fatty acid that is a sustainable approach to increasing tissue concentrations of long-chain polyunsaturated n-3 fatty acids.

Long-term up to 24-month efficacy and safety of concomitant prescription omega-3-acid ethyl esters and simvastatin in hypertriglyceridemic patients

OBJECTIVE

Assess the long-term efficacy and safety of prescription omega-3-acid ethyl esters (P-OM3) coadministered with simvastatin in an extension of the Combination of Prescription Omega-3 Plus Simvastatin (COMBOS) trial.

METHODS

COMBOS included hypertriglyceridemic patients (triglyceride [TG] >or=200 mg/dL and <500 mg/dL or >or=2.26 mmol/L and <5.64 mmol/L) with low density lipoprotein cholesterol (LDL-C) level no greater than 10% above the National Cholesterol Education Program, Adult Treatment Panel III treatment goal. After an 8-week lead-in phase with simvastatin 40 mg/day (which continued throughout the trial), subjects were randomized to 8 weeks of P-OM3 4 g/day or placebo. Completers were eligible to participate in a 24-month extension study. Those who received placebo + simvastatin in COMBOS switched to open-label P-OM3 + simvastatin ('Switchers'); those who received P-OM3 + simvastatin during COMBOS continued the same regimen (open-label) in the extension phase ('Non-switchers'). The primary endpoint was the difference between Non-switchers and Switchers in median percent change in non-high-density lipoprotein-cholesterol (non-HDL-C) from COMBOS end of treatment to Month 4 of the extension phase.

RESULTS

At Month 4 from COMBOS end of treatment, non-HDL-C was reduced by a median of 9.4% in Switchers and increased by 0.9% in Non-switchers (p < 0.001). For the total population (combined Non-switcher + Switcher population), the median percent change from COMBOS baseline to Months 4, 12, and 24 was -8.3%, -7.3%, and -8.9%, respectively (all p < 0.001). This extension study revealed no unexpected safety findings. A limitation of this study was a gap between completion of COMBOS and enrollment in the extension phase for some patients; however, a post-hoc non-HDL-C sensitivity analysis performed at the 4-month primary endpoint revealed no influence of gap on study results.

CONCLUSIONS

In this 24-month extension study, P-OM3 was generally well tolerated, and produced sustained reductions in non-HDL-C levels in simvastatin-treated patients with TG levels between 200 and 500 mg/dL (2.26 mmol/L and 5.64 mmol/L).

CLINICAL TRIAL REGISTRY NUMBER

NCT00903409.

Acute fish oil and soy isoflavone supplementation increase postprandial serum (n-3) polyunsaturated fatty acids and isoflavones but do not affect triacylglycerols or biomarkers of oxidative stress in overweight and obese hypertriglyceridemic men

Chronic consumption of fish and fish oil high in (n-3) PUFA reduces triacylglycerols (TG) but may increase oxidative stress, whereas consumption of soy isoflavones may reduce oxidative stress. Elevated serum TG and oxidative stress are considered cardiovascular disease (CVD) risk factors, but the effects of acute (n-3) PUFA and soy isoflavones on these CVD risk factors are unknown. The purpose of the study was to determine the effects of acutely supplementing a high-fat, high-fructose meal with fish oil and isoflavone placebo (FO) and fish oil placebo and soy isoflavones (ISO). In a randomized, double-blind, placebo-controlled, crossover study, 10 overweight or obese men consumed a high-fat, high-fructose meal with 4 dietary supplement combinations: fish oil placebo and isoflavone placebo (placebo); fish oil and isoflavone placebo (FO); fish oil placebo and isoflavones (ISO); and fish oil and isoflavones (FO + ISO). Serum collected at baseline and at 2, 4, and 6 h postprandially was analyzed for fatty acids, isoflavones, TG, and oxidative stress biomarkers (lipid hydroperoxides, oxidized-LDL, total antioxidant status). FO significantly increased serum (n-3) PUFA and ISO increased serum isoflavones. The study meal significantly increased serum total fatty acids and TG without affecting oxidative stress biomarkers. Serum TG and oxidative stress biomarkers did not differ between treatments. The FO and ISO were bioavailable but did not attenuate the postprandial rise in serum TG. Neither the study meal nor the FO or ISO induced significant changes in oxidative stress biomarkers. The current study adds to a limited literature on the acute effects of FO and ISO interventions on postprandial biomarkers of CVD risk.

Dispelling the myths about omega-3 fatty acids

Although there is an enormous amount of information available on omega-3 fatty acids, it is sometimes misleading, contradictory, and unsupported by scientific fact. Consumers and medical professionals may be confused regarding the potential value of omega-3 fatty acid supplements, despite having either read or heard about fi sh oil consumption and/or omega-3 fatty acid benefits and risks. The availability of a prescription formulation of omega-3-acid ethyl esters (P-OM3) has provided important new information that helps to dispel the myths and alleviate concerns surrounding the use of omega-3 fatty acids in clinical practice. The safety and efficacy of P-OM3, but not dietary-supplement omega-3 fatty acids, are documented in placebo-controlled trials. In general, studies using Food and Drug Administration-approved dosages of P-OM3 have not substantiated various myths surrounding the negative effects of omega-3 fatty acids. Thus, there are now evidence-based clinical guidelines for the use of omega-3 fatty acids in clinical practice.

Macronutrient intake and modulation on chylomicron production and clearance

The extent and kinetics of postprandial changes are highly variable and are modulated by numerous factors including diet, lifestyle conditions, genetic background and pathological conditions. This review focuses on dietary factors affecting postprandial chylomicron and lipoprotein metabolism in humans. The first key step in the process is fat digestion within the stomach and small intestine which can be modulated by fat and dietary fiber amounts and types. The second key step is intestinal absorption per se. The uptake and secretion of absorbed nutrients in chylomicrons is affected by numerous factors, including nutrients themselves. The amount of dietary triglycerides as well as the nature of fatty acids ingested from habitual diet or present in a test meal modulates the extent of chylomicron and plasma triglyceride levels postprandially. The amount of dietary cholesterol also modulates the extent of postprandial chylomicron and plasma triglycerides. Other nutrients can alter the postprandial occurrence of chylomicrons such as proteins, alcohol, carbohydrates or fibers. Addition of glucose and more markedly fructose, to a fat test meal increases the accumulation of chylomicrons, as does a high-glycemic index meal. In contrast, some sources of dietary fibers such as oat bran noticeably decrease the occurrence of chylomicron postprandially. Overall, changing the habitual dietary pattern, for instance from a Western-type diet to Mediterranean-type one, can in turn alter the postprandial response of the subjects. The last step in postprandial lipid metabolism is clearance from plasma through combined lipolysis processes and tissue uptake of chylomicron remnants. Both the processes can also be modulated by the nutrients. Because most day-time is usually spent in a postprandial state, the link between dietary patterns and cardiovascular health or risk is clearly mediated by the secretion and clearance rates of chylomicrons in the circulation.

Role of n-3 fatty acids in the treatment of hypertriglyceridemia and cardiovascular disease

n-3 Fatty acids (FAs) when used in doses of 3-4 g/d eicosapentaenoic acid and docosahexaenoic acid have profound effects on triacylglycerol (TG) concentrations. The mechanism for their TG reduction relates to their favorable effects on reducing hepatic production and secretion of VLDL and VLDL apolipoprotein B particles, along with favorable effects on plasma lipolytic activity through lipoprotein lipase-mediated clearance, as well as stimulation of beta-oxidation of other FAs in the liver. Their hypotriglyceridemic properties are related to both the dose of n-3 FAs used and the baseline TG concentrations of the population. In patients with TG concentrations >500 mg/dL, 4 g n-3 FAs have been shown to reduce TGs by 45%, VLDL by 42%, and non-HDL by 10.2%. A recent pooled meta-analysis with multiple doses of n-3 FAs ranging from 0.8 to 5.4 g revealed changes in TGs of -27 mg/dL (95% CI: -33, -20), in HDL of +1.6 mg/dL (95% CI: + 0.8, +2.3), and in LDL cholesterol of +6 mg/dL (95% CI: + 3, +8). The clinical uses of n-3 FAs include treatment of severe and moderate hypertriglyceridemia, use in statin-treated patients with elevated TG concentrations or non-HDL cholesterol (mixed hyperlipidemia), and use in the secondary and primary prevention of cardiovascular disease. Existing large-scale clinical trials such as the GISSI-Prevenzione Study and JELIS with low doses of n-3 FAs (1-2 g) show clinical benefit in reducing coronary heart disease without substantial changes in concentrations of TGs or other lipids. Future clinical trials need to determine whether the TG-lowering doses of n-3 FAs (3-4 g/d) result in additional risk reduction.

Fish oil in the treatment of dyslipidemia

PURPOSE OF REVIEW

The recent availability of a concentrated prescription omega-3 fatty acid preparation provides physicians with an additional anti-dyslipidemic agent at a time when limitations of statin therapy in dyslipidemic high-risk patients are recognized. This review examines the evidence supporting the use of omega-3 fatty acid treatment in dyslipidemic states.

RECENT FINDINGS

There is now considerable evidence that omega-3 fatty acid treatment at the prescription strength of 4 g/day effectively and safely lowers triglyceride levels and increases low-density lipoprotein size, as well as affecting high-density lipoprotein metabolism. Similar effects have been noted in patients treated with statins, and add-on prescription omega-3 fatty acid therapy significantly increases the proportion of statin-treated dyslipidemic patients reaching their non-high-density lipoprotein cholesterol goals. In addition to past studies showing a cardioprotective effect of low-dose omega-3 fatty acid treatment against sudden death, a recent controlled clinical trial showed that 1.8 g of omega-3 fatty acid in statin-treated patients reduced major coronary events by 19% compared with statin plus placebo treatment.

SUMMARY

Omega-3 fatty acid treatment should be considered in patients with severe hypertriglyceridemia as well as in high-risk patients with an atherogenic lipoprotein phenotype.

Omega-3 fatty acid containing diets decrease plasma triglyceride concentrations in mice by reducing endogenous triglyceride synthesis and enhancing the blood clearance of triglyceride-rich particles

BACKGROUND & AIMS

Intake of n-3 fatty acids can reduce both fasting and postprandial triglyceride (TG) concentrations in humans as well as in experimental animals, but the mechanisms by which this occurs are not completely known. We investigated in mice the effects of dietary fish oil (a source of n-3 fatty acids) on endogenous TG synthesis and exogenous TG-rich particle removal.

METHODS

C57 BL/6J mice were fed for 4 months with three types of high-fat diets (18% fat wt/wt) - soy oil, fish oil and a mixture of soy oil and fish oil (soy/fish) (5:1 wt/wt), and a chow diet with 6% fat from soy oil (wt/wt) served as a control. Plasma TG and apolipoprotein B (apoB) concentrations and lipoprotein lipase (LPL) activity were measured. Triton WR 1339 was used to assess hepatic synthesis of very low density lipoprotein, and intravenous injection of chylomicron-like lipid emulsions was conducted to determine the effects of dietary fish oil n-3 fatty acids on exogenous TG clearance.

RESULTS

Both fish and soy/fish oil diets reduced plasma TG levels in fed and fasted states compared to soy oil alone. Plasma pre- and post-heparin LPL activities were significantly higher with fish and soy/fish oil diets than soy oil diet in fed mice. No differences in plasma TG levels and LPL activity were shown among groups of fish oil, soy/fish oil and normal chow diets. Levels of hepatic TG and apoB synthesis were 30-50% and 42% lower in mice fed with the fish oil diet compared to the other three diets. In addition, compared to soy oil diet, fish oil feeding significantly increased blood clearance of chylomicron-like lipid emulsions by 21-26%.

CONCLUSIONS

Our data suggest that reduced endogenous TG synthesis, increased LPL activities and more rapid blood clearance of TG-rich particles all distinctly contribute to the TG-lowering effects of fish oil n-3 fatty acids.

Effects of organohalogen pollutants on haematological and urine clinical-chemical parameters in Greenland sledge dogs (Canis familiaris)

Seven West Greenland sledge dog bitches (Canis familiaris) and their three pups were fed 50-200 g of contaminated West Greenland minke whale (Balaenoptera acutorostrata) blubber, and in a control cohort eight sister bitches and their five pups were fed a similar amount pork fat. Blood plasma and urine clinical-chemical parameters were measured and compared between the bitches and pups form the control and exposed cohorts. Based on existing reference intervals, Arctic mammals may have blood clinical-chemical endpoint levels that differ from comparable species at lower latitudes. The cortisol:creatinine ratio, protein:creatinine ratio, alkaline phosphatase, cholesterol and inorganic phosphate were significantly highest (ANCOVA: all p<0.05) in the pup generation. The cortisol:creatinine ratio, cholesterol, lactate dehydrogenase and creatinine kinase were significantly higher (ANCOVA: all p<0.05) in the control group, while glucose was significantly highest (ANCOVA: p<0.05) in the exposed group. Furthermore, the blood cholesterol levels indicate that exposure via the diet to marine mammal blubber has a preventive effect on the development of cardiovascular diseases. We therefore suggest that the consumption of contaminated Arctic marine blubber impacted liver and kidney function in adult and pup sledge dogs.

Dietary, physiological, genetic and pathological influences on postprandial lipid metabolism

Most of diurnal time is spent in a postprandial state due to successive meal intakes during the day. As long as the meals contain enough fat, a transient increase in triacylglycerolaemia and a change in lipoprotein pattern occurs. The extent and kinetics of such postprandial changes are highly variable and are modulated by numerous factors. This review focuses on factors affecting postprandial lipoprotein metabolism and genes, their variability and their relationship with intermediate phenotypes and risk of CHD. Postprandial lipoprotein metabolism is modulated by background dietary pattern as well as meal composition (fat amount and type, carbohydrate, protein, fibre, alcohol) and several lifestyle conditions (physical activity, tobacco use), physiological factors (age, gender, menopausal status) and pathological conditions (obesity, insulin resistance, diabetes mellitus). The roles of many genes have been explored in order to establish the possible implications of their variability in lipid metabolism and CHD risk. The postprandial lipid response has been shown to be modified by polymorphisms within the genes for apo A-I, A-IV, A-V, E, B, C-I and C-III, lipoprotein lipase, hepatic lipase, fatty acid binding and transport proteins, microsomal triglyceride transfer protein and scavenger receptor class B type I. Overall, the variability in postprandial response is important and complex, and the interactions between nutrients or dietary or meal compositions and gene variants need further investigation. The extent of present knowledge and needs for future studies are discussed in light of ongoing developments in nutrigenetics.

Role of prescription omega-3 fatty acids in the treatment of hypertriglyceridemia

A prescription form of omega-3 fatty acids has been approved by the United States Food and Drug Administration as an adjunct to diet for the treatment of very high triglyceride levels. The active ingredients of omega-3 fatty acids are eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are responsible for the triglyceride lowering. The prescription product contains a total of 0.84 g of these two active ingredients in every 1-g capsule of omega-3 fatty acids. The total EPA and DHA dose recommended for triglyceride lowering is approximately 2-4 g/day. Fish oil products containing EPA and DHA are available without a prescription, but the American Heart Association advises that therapy with EPA and DHA to lower very high triglyceride levels should be used only under a physician's care. In patients with triglyceride levels above 500 mg/dl, approximately 4 g/day of EPA and DHA reduces triglyceride levels 45% and very low-density lipoprotein cholesterol levels by more than 50%. Low-density lipoprotein cholesterol levels may increase depending on the baseline triglyceride level, but the net effect of EPA and DHA therapy is a reduction in non-high-density lipoprotein cholesterol level. Alternatively, patients may receive one of the fibrates (gemfibrozil or fenofibrate) or niacin for triglyceride lowering if their triglyceride levels are higher than 500 mg/dl. In controlled trials, prescription omega-3 fatty acids were well tolerated, with a low rate of both adverse events and treatment-associated discontinuations. The availability of prescription omega-3 fatty acids, which ensures consistent quality and purity, should prove to be valuable for the medical management of hypertriglyceridemia.

Interaction of exercise training andn-3 fatty acid supplementation on postprandial lipemia

The effect of combining omega-3 fatty acid (n-3 FA) supplementation and exercise training treatment on postprandial lipemia (PPL) has not been studied. The purpose of this study was to examine the interaction of n-3 FA and exercise training in attenuating PPL after a high-fat meal. Previously sedentary, overweight, subjects (n = 22; 12 women, 10 men, BMI 26.6 ±0.7 kg/m2) were randomly assigned to one of two treatment groups: n-3 FA supplementation alone (FO, n = 10) or n-3 FA supplementation plus exercise training (FO+ExTr, n = 12). Both groups consumed 4 g/d n-3 FA, and one group also exercise trained for 45 min/d, 5d/week of brisk walking and (or) jogging at 60% VO2 max. Before and after 4 weeks of treatment, subjects performed a baseline PPL and a PPL following a single session of exercise (ExPPL). PPL was assessed by triglyceride (TG) area under the curve (AUC) and peak TG response (TGpeak). A two-way analysis of variance (ANOVA) with repeated measures was used to compare results from treatments for baseline and exercise trials. FO alone reduced PPL and Ex PPL, and FO+ExTr attenuated the ExPPL response measured as total AUC and TGpeak. There was no significant main effect for group or group by time interaction for baseline PPL or ExPPL. Fasting high-density lipoprotein cholesterol (HDL-C) and HDL2-C (i.e., subfraction 2) concentrations were significantly increased in the FO+ExTr group after the treatments. These results suggest that n-3 FA supplementation reduced PPL in sedentary subjects. Exercise training has no interference or additive effects with n-3 FA supplementation in attenuating PPL, but combined treatments may be additive in raising high-density lipoprotein cholesterol.

Plasma triacylglycerol and coagulation factor concentrations predict the anticoagulant effect of dietary fish oil in overweight subjects

Fish oil, containing (n-3) PUFA, is associated with a moderate reduction in cardiovascular disease through a multifactorial mechanism involving a decrease in plasma lipids and anticoagulant activity. Two intervention studies on subjects at risk were performed to determine the relation of these 2 fish-oil effects. In study 1, 54 overweight subjects consumed 3.1 g (n-3) PUFA daily. In study 2, which involved 42 overweight patients with type 2 diabetes, 20 subjects consumed (n-3) PUFA, whereas 22 others ingested a preparation rich in (n-6) PUFA. Tissue factor-induced thrombin generation (thrombin potential) was determined as an integrated measure of plasma coagulant activity. In both studies, multivariate analysis indicated a strong clustering of fasting concentrations of triacylglycerols, prothrombin, factor V, factor VII, and factor X with one another at baseline. This cluster of factors determined partly the interindividual variation in thrombin generation, of which prothrombin and triacylglycerol concentrations were the main determinants. In both healthy subjects and diabetes patients, high triacylglycerol concentrations (>1.69 mmol/L) at baseline were closely linked to a strong fish oil-induced lowering of triacylglycerol and coagulation factor V, VII, and X concentrations, and thrombin generation. We conclude that high fasting triacylglycerol concentrations predict high procoagulant activity and a lowering of thrombin potential with dietary fish oil.

Clinical overview of Omacor: a concentrated formulation of omega-3 polyunsaturated fatty acids

Omacor (omega-3-acid ethyl esters; Reliant Pharmaceuticals, Inc., Liberty Corner, NJ) is a highly purified, prescription omega-3 fatty acid formulation with high concentrations of eicosapentaenoic acid (EPA) (465 mg) and docosahexaenoic acid (DHA) (375 mg) in each 1-g capsule, along with 4 mg (6 IU) of vitamin E. At a typical dose of 4 capsules/day, Omacor significantly lowers plasma triglyceride levels either as monotherapy or in combination with 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) or fibrates. Omacor also modestly increases plasma levels of low-density lipoprotein cholesterol, increases high-density lipoprotein cholesterol levels, and has favorable effects on lipoprotein particle size and subclass distribution. Omacor is well tolerated, with few side effects other than mild gastrointestinal symptoms. Hyperglycemia, abnormal bleeding, elevations in muscle or liver enzymes, and/or abnormalities in kidney or nerve function have not been reported. Through its intensive purification process, Omacor has minimal "fishy" smell and taste, and it has not been reported to cause hypervitaminosis or illness due to exposure to environmental toxins. Omacor provides a safe, effective, well-tolerated approach to management of hypertriglyceridemia.

Effect of docosahexaenoic acid administration on plasma lipid profile and metabolic parameters of children with methylmalonic acidaemia

AIM

To evaluate the effect of administration of docosahexaenoic acid (DHA) on dyslipidaemia, plasma fatty acid composition and metabolic parameters of children with isolated methylmalonic acidaemia (MMA) (McKusick 25100).

METHODS

Four children (3 male, 1 female) with MMA (mut(0)), participated in a crossover, randomized study of DHA administration (25 mg/kg per day, divided into three daily doses). The control group comprised 56 healthy children, aged 10+/- 2.7 years, (51 male, 5 female), who were followed in our clinic owing to possible familial risk of cardiovascular disease.

RESULTS

The comparison of plasma fatty acid composition of children with MMA versus control children demonstrated that the patients had significantly higher values for oleic acid (p = 0.004) and linolenic acid (p = 0.008). No differences were observed in the levels of DHA and arachidonic acid. Plasma concentrations of insulin, glycine, ammonia, total cholesterol and cholesterol fractions did not change with DHA administration. No significant changes were observed in urinary excretion of methylmalonic acid. As expected, the percentage of DHA and n-3 fatty acids in plasma increased significantly after therapy (p = 0.005 and 0.014, respectively). The most remarkable result was a decrease of plasma levels of triglycerides after DHA therapy (p = 0.014).

CONCLUSION

As previously found in normal children, dietary supplementation with DHA decreases the triglyceride levels, normalizing the hypertriglyceridaemia of these children without any evidence of short-term adverse effects.

Exercise plus n-3 fatty acids: additive effect on postprandial lipemia

The purpose of this study was to examine changes in postprandial lipemia (PPL) in recreationally active males following aerobic exercise, omega-3 fatty acids (n-3FA) supplementation, and the combination of the two. PPL following a high-fat meal was measured in 10 recreationally active males (25 +/-1.5 years) under each of the following conditions: no exercise and no n-3 FA supplementation (control); exercise and no n-3FA supplementation (exercise); n-3FA supplementation and no exercise (n-3FA); and exercise and n-3 FA supplementation (combined). Blood was collected before the high-fat meal and at 2, 4, 6, and 8 hours after the meal to assess the PPL response. Supplementation consisted of 4.0 g of n-3FA per day for 5 weeks. Triglyceride (TG) peak response, the total area under the TG curve (TG-AUCT), and the incremental area under the TG curve (TG-AUCI) were used to define the PPL response. TG peak response was significantly reduced 38% by n-3FA supplementation and 50% by the combination of exercise and n-3FA supplementation. N-3FAs significantly reduced the TG-AUCT by 27% and by 42% when combined with exercise. When compared with the exercise trial, the TG-AUCT during the combined trial was significantly lower. Exercise, n-3FAs, and the combination significantly reduced the TG-AUCI by 40%, 42%, and 58%, respectively. These results suggest that the combination of exercise and n-3FA supplementation reduce PPL to a greater degree in recreationally active males when compared with the individual treatments.

Lipoprotein transport in the metabolic syndrome: pathophysiological and interventional studies employing stable isotopy and modelling methods

The accompanying review in this issue of Clinical Science [Chan, Barrett and Watts (2004) Clin. Sci. 107, 221–232] presented an overview of lipoprotein physiology and the methodologies for stable isotope kinetic studies. The present review focuses on our understanding of the dysregulation and therapeutic regulation of lipoprotein transport in the metabolic syndrome based on the application of stable isotope and modelling methods. Dysregulation of lipoprotein metabolism in metabolic syndrome may be due to a combination of overproduction of VLDL [very-LDL (low-density lipoprotein)]-apo (apolipoprotein) B-100, decreased catabolism of apoB-containing particles and increased catabolism of HDL (high-density lipoprotein)-apoA-I particles. These abnormalities may be consequent on a global metabolic effect of insulin resistance, partly mediated by depressed plasma adiponectin levels, that collectively increases the flux of fatty acids from adipose tissue to the liver, the accumulation of fat in the liver and skeletal muscle, the hepatic secretion of VLDL-triacylglycerols and the remodelling of both LDL (low-density lipoprotein) and HDL particles in the circulation. These lipoprotein defects are also related to perturbations in both lipolytic enzymes and lipid transfer proteins. Our knowledge of the pathophysiology of lipoprotein metabolism in the metabolic syndrome is well complemented by extensive cell biological data. Nutritional modifications may favourably alter lipoprotein transport in the metabolic syndrome by collectively decreasing the hepatic secretion of VLDL-apoB and the catabolism of HDL-apoA-I, as well as by potentially increasing the clearance of LDL-apoB. Several pharmacological treatments, such as statins, fibrates or fish oils, can also correct the dyslipidaemia by diverse kinetic mechanisms of action, including decreased secretion and increased catabolism of apoB, as well as increased secretion and decreased catabolism of apoA-I. The complementary mechanisms of action of lifestyle and drug therapies support the use of combination regimens in treating dyslipoproteinaemia in subjects with the metabolic syndrome.

Dietary PUFA and the metabolic syndrome in Indian Asians living in the UK

Indian Asians living in the UK have a 50% higher CHD mortality rate compared with the indigenous Caucasian population, which cannot be attributed to traditional risk factors. Instead, features of the metabolic syndrome, including raised plasma triacylglycerol, reduced HDL-cholesterol (HDL-C) and an increased proportion of small dense LDL particles, together with insulin resistance and central obesity, are prevalent among this population. The present review examines evidence to support the hypothesis that an imbalance in dietary PUFA intake, specifically a higher intake of n-6 PUFA in combination with the lower intake of the long-chain (LC) n-3 PUFA, plays an important role in the prevalence of the metabolic syndrome observed in Indian Asians. Data are presented to illustrate the impact of manipulation of the background n-6 PUFA intake (moderate or high n-6 PUFA) and the subsequent response to supplementation with LC n-3 PUFA on blood lipids and insulin action in a group of Indian Asian volunteers. The results demonstrate that supplementation with LC n-3 PUFA had no impact on insulin action in those subjects consuming either the moderate- or high-n-6 PUFA diet. In the postprandial phase reductions in plasma triacylglycerol concentrations were greater in those consuming the high-n-6 PUFA background diet subsequent to fish oil supplementation. The present study concludes that, contrary to the central hypothesis, the prevalence of metabolic abnormalities in Indian Asians compared with Caucasians may not be attributable to differences in intakes of n-6 and n-3 PUFA.

Feeding minipigs fish oil for four weeks lowers postprandial triacylglycerolemia

We wanted to establish a minipig model for the study of postprandial lipemia and plasma lipid clearance after fish oil consumption. Seven minipigs were fed a fish oil-enriched nonpurified diet and a control diet for 4 wk in a randomized cross-over study. After each intervention period, each pig was challenged with a gastric fat load (2 g fat/kg body) and an intravenous fat bolus (0.1 g/kg body) on separate days. Frequent blood samples were collected for 6 h after the gastric fat load and for 40 min after the intravenous bolus. The fish oil-enriched diet was associated with lower triacylglycerol, glycerol and nonesterified fatty acid concentrations in the hours after the gastric fat load than the control diet (P < 0.05). In contrast, the triacylglycerol disappearance rate after the intravenous fat bolus was not affected by fish oil (P = 0.19). In conclusion, dietary fish oil supplementation attenuates postprandial lipemia in minipigs similarly to what occurs in humans. Minipigs could serve as a useful model for future studies of this phenomenon. We observed no significant effect of fish oil supplementation on plasma triacylglycerol clearance and thus were unable to identify the mechanism explaining the attenuated lipemia in minipigs.

Effect of xuezhikang, a cholestin extract, on reflecting postprandial triglyceridemia after a high-fat meal in patients with coronary heart disease

The effect of xuezhikang on postprandial triglyceride (TG) level was investigated in patients with coronary heart disease (CHD) after a high-fat meal (800 cal; 50 g fat). Fifty CHD patients were randomly divided into two groups to accept xuezhikang (xuezhikang group) 1200 mg/day (600 mg twice daily) or not (control group) on the base of routine therapy which included aspirin, metoprolol and fosinopril and nitrates during the whole 6 weeks following-up. Xuezhikang significantly reduced fasting serum total cholesterol (TC) (-20%), low-density lipoprotein cholesterol (LDL-C, -34%), TG (-32%) and apoB (-27%) levels, and raised fasting high-density lipoprotein cholesterol (HDL-C, 18%) and apoA-I (13%) levels (P<0.001). The postprandial serum TG levels at 2, 4 and 6 h decreased 32, 38 and 43%, respectively, in xuezhikang group (P<0.001). The TG area under the curve over the fasting TG level (TG-AUC) significantly decreased in CHD patients accepted xuezhikang with normal (less than 1.7 mmol/l) and elevated (1.74 to 2.92 mmol/l) fasting TG levels by 45 and 50%, respectively (P<0.001). Routine therapy had no significant effect on the fasting and postprandial lipid and apolipoprotein levels. The change of TG-AUC was significantly related to the changes of fasting TG, TC, LDL-C, and HDL-C levels after the treatment, which were related to the changes of fasting apoA-I and apoB levels significantly (P<0.001). Xuezhikang was shown to be beneficial in the treatment of reflecting postprandial triglyceridemia in CHD patients with normal and mildly elevated fasting TG levels.

Randomized controlled trial of the effect of n-3 fatty acid supplementation on the metabolism of apolipoprotein B-100 and chylomicron remnants in men with visceral obesity

BACKGROUND

Lipid abnormalities may contribute to the increased risk of atherosclerosis and coronary disease in visceral obesity. Fish oils lower plasma triacylglycerols, but the underlying mechanisms are not fully understood.

OBJECTIVE

We studied the effect of fish oils on the metabolism of apolipoprotein B-100 (apo B) and chylomicron remnants in obese men.

DESIGN

Twenty-four dyslipidemic, viscerally obese men were randomly assigned to receive either fish oil capsules (4 g/d, consisting of 45% eicosapentaenoic acid and 39% docosahexaenoic acid as ethyl esters) or matching placebo (corn oil, 4 g/d) for 6 wk. VLDL, intermediate-density lipoprotein (IDL), and LDL apo B kinetics were assessed by following apo B isotopic enrichment with the use of gas chromatography-mass spectrometry after an intravenous bolus injection of trideuterated leucine. Chylomicron remnant catabolism was measured with the use of an intravenous injection of a chylomicron remnant-like emulsion containing cholesteryl [(13)C]oleate, and isotopic enrichment of (13)CO(2) in breath was measured with isotope ratio mass spectrometry. Kinetic values were derived with multicompartmental models.

RESULTS

Fish oil supplementation significantly (P < 0.05) lowered plasma concentrations of triacylglycerols (-18%) and VLDL apo B (-20%) and the hepatic secretion of VLDL apo B (-29%) compared with placebo. The percentage of conversions of VLDL apo B to IDL apo B, VLDL apo B to LDL apo B, and IDL apo B to LDL apo B also increased significantly (P < 0.05): 71%, 93%, and 11%, respectively. Fish oils did not significantly alter the fractional catabolic rates of apo B in VLDL, IDL, or LDL or alter the catabolism of the chylomicron remnant-like emulsion.

CONCLUSION

Fish oils effectively lower the plasma concentration of triacylglycerols, chiefly by decreasing VLDL apo B production but not by altering the catabolism of apo B-containing lipoprotein or chylomicron remnants.

A Patient with Severe Hypertriglyceridemia Associated with Anemia and Hypoalbuminemia

We report a patient with severe hypertriglyceridemia associated with anemia and hypoalbuminemia, in which the former may have caused the latter two conditions. This is the first reported case of abrupt onset of severe hypertriglyceridemia resulting in suppression of bone marrow and liver function.

Postprandial dyslipidemia: an atherogenic disorder common in patients with diabetes mellitus

The increased risk of coronary artery disease among patients with diabetes mellitus is attributable, in part, to specific disorders of lipoprotein metabolism that are common in this population. These include disordered metabolism of very-low-density lipoprotein and/or chylomicrons that may be proatherogenic. Elevated postprandial triglycerides, peak postprandial triglyceridemia, and late postprandial triglyceride levels have been associated in clinical trials with both early coronary artery and carotid artery atherosclerosis for persons with normal lipid profiles and those with mild-to-moderate hyperlipidemia, independently of established risk factors. If hyperlipidemia cannot be managed through better glycemic control, diet, and exercise, then hepatic 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, fibric acid derivatives, and omega-3 fatty acids are safe and effective lipid-altering agents that can be used to correct these disorders.

Postprandial lipid handling

The etiological importance of postprandial lipid metabolism in the development of coronary artery disease is now well established. Since then, the work of Patsch and others has helped to establish the etiological importance of postprandial lipid metabolism in the development of coronary artery disease. Dietary and pharmacological interventions have been shown to produce dramatic improvement in postprandial lipid handling in high risk groups and have potential to prevent coronary artery disease through these effects. Research effort continues to focus on the complex mechanisms which underlie defects in postprandial lipid handling, with a view to understanding how lifestyle variables such as diet can be modified to prevent coronary artery disease.