Polyunsaturated Fatty Acids In Patients Research Articles

Marine n-3 Polyunsaturated Fatty Acids in Patients With End-stage Renal Failure and in Subjects Without Kidney Disease: A Comparative Study

Patients with end-stage renal disease treated with chronic hemodialysis (HD) are reported to have low levels of marine n-3 polyunsaturated fatty acids (PUFA) in plasma and cell membranes compared with healthy subjects. The aim of this study was to investigate whether n-3 PUFA levels in plasma and cells are lower in HD patients as compared with subjects without kidney disease. A comparative study was carried out. This study was carried out at the Departments of Nephrology and Cardiology, Aalborg Hospital, Aarhus University Hospital, Denmark. This study consisted of 2 study populations comprising HD patients and 5 study populations comprising subjects without kidney disease. The fatty acid distribution in plasma phospholipids and platelet phospholipids was measured using gas chromatography. Eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and arachidonic acid (AA) levels in plasma or serum phospholipids and platelet phospholipids in HD patients were compared with n-3 PUFA levels in subjects without kidney disease. EPA and DHA were lower and AA/EPA was higher in plasma/serum phospholipids in HD patients than in subjects without kidney disease. Similarly, higher AA and AA/EPA and lower EPA and DHA levels were found in platelet phospholipids of HD patients. Adjustment for gender, age, and habitual intake of fish and fish oil supplements did not change these results. HD patients have lower n-3 PUFA levels in plasma and cells compared with subjects without kidney disease.

Transmyocardial Gradient of Polyunsaturated Fatty Acid Associate With the Washout Rate of Tc-99m Sestamibi

Background: In myocardium of failing heart, utilization of polyunsaturated fatty acids (PUFAs),which affect composition of mitochondrial membrane, is still unknown.On the other hand, Tc-99m sestamibi (MIBI) is taken into mitochondria depending on its membrane potential and the washout rate of MIBI (WOR) reflect mitochondrial function. Therefore, we studied transmyocardial gradient of PUFAs in patients with idiopathic dilated cardiomyopathy (DCM) and association between transmyocardial gradient of PUFAs and WOR.

Takotsubo cardiomyopathy and elevated troponin levels following cerebral seizure

left ventricular ejection fractions and congestive heart failure. N Engl J Med 1991;325:293–302. [5] CIBIS-II Investigators and Committee. The cardiac insufficiency bisoprolol study II (CIBIS-II): a randomised trial. Lancet 1999;353:9–13. [6] Allen LA, Rogers JG, Warnica JW, et al. Escape investigators and coordinators. High mortality without ESCAPE: the registry of heart failure patients receiving pulmonary artery catheters without randomization. J Card Fail 2008;14:661–9. [7] Investigators Gissi-HF. Effect of n-3 polyunsaturated fatty acids in patients with chronic heart failure (the GISSI-HF trial): a randomised, double-blind, placebocontrolled trial. Lancet 2008;372:1223–30. [8] Coats AJ. Ethical authorship and publishing. Int J Cardiol 2009;131:149–50.

Effects of a 1-year dietary intervention with n-3 polyunsaturated fatty acid-enriched olive oil on non-alcoholic fatty liver disease patients: a preliminary study

Background and aims Non-alcoholic fatty liver disease (NAFLD) is a worldwide diffuse condition due to alimentary, environment and genetic factors. The aim of our preliminary study was to evaluate the effectiveness of long-term consumption of food enriched with n-3 polyunsaturated fatty acids (PUFA) in patients with NAFLD.Methods Eleven patients were enrolled; six (four males, two females) were planned for oral administration of 6.5 ml olive oil enriched with n-3 PUFA for 12 months, while five (four males, one female) were used as controls.Results Consumption of olive oil enriched with n-3 PUFA demonstrated a significant improvement of liver echo-texture and of the Doppler Perfusion Index after 12 months (after: 0.19 ± 0.02 vs. pre: 0.15 ± 0.03; P < 0.05), whereas no significant changes were seen at the end of follow-up in controls. Moreover, patients who consumed the olive oil enriched with n-3 PUFA showed a significant amelioration of liver enzymes, and of triglycerides (post: 132.8 ± 63.7 vs. pre: 164.5 ± 85.5 mg/dl; P = 0.04) in a general linear model adjusted for age and gender. Interestingly, patients reported to have a significant increase of adiponectin levels (post: 1,487.9 ± 96.7 vs. pre: 1,143 ± 24.8 μg/ml; P = 0.04).Conclusion The results of this preliminary study showed that long-term consumption of olive oil enriched with n-3 PUFA in patients with NAFLD is able to decrease circulating liver enzymes and triglycerides, with a significant improvement of adiponectin levels.

A Meta-Analytic Review of Polyunsaturated Fatty Acid Compositions in Patients with Depression

On the basis of evidence from studies showing the antidepressant effects of omega-3 polyunsaturated fatty acids and the inverse relation between fish consumption and the prevalence of depression, the phospholipid hypothesis seems promising in ascertaining the etiology and treatment of depression. Although several studies have shown lower levels of omega-3 (n-3) polyunsaturated fatty acids in depressive patients, the results of individual polyunsaturated fatty acids, including docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and the omega-6 (n-6) polyunsaturated fatty acid arachidonic acid (AA), were inconsistent. We conducted the meta-analyses of 14 studies comparing the levels of polyunsaturated fatty acids between depressive patients and control subjects. The effect size of each study was synthesized by using a random effects model. Compared with control subjects, the levels of EPA, DHA, and total n-3 polyunsaturated fatty acids were significantly lower in depressive patients. There was no significant change in AA or total n-6 polyunsaturated fatty acids. The results showed lower levels of EPA, DHA, and total n-3 polyunsaturated fatty acids in patients with depression, thus implying that n-3 polyunsaturated fatty acids play a role in the pathogenesis of depression. Our findings provide further support to the phospholipid hypothesis of depression and a rationale for using n-3 polyunsaturated fatty acids as an alternative treatment for depression. With these results, future studies examining specific roles of DHA and EPA in different clusters of depressive symptoms are warranted.

Change in the fatty acid pattern of erythrocyte membrane phospholipids after oral supplementation of specific fatty acids in patients with gastrointestinal diseases

The fatty acid pattern of membrane phospholipids is suggested to affect membrane fluidity and epithelial barrier function as a result of membrane fatty acid unsaturation. The incorporation of n-3 polyunsaturated fatty acids (PUFAs) into membrane phospholipids may diminish inflammatory potential in patients with gastrointestinal diseases. The aim of this study was to improve the fatty acid profile of erythrocyte membrane phospholipids after oral supplementation of specific fatty acids in patients with maldigestion and/or malabsorption. We conducted a randomized, double-blind, controlled trial. A total of 48 patients with gastrointestinal diseases received either fat-soluble vitamins A,D,E,K (ADEK) or ADEK plus fatty acids alpha-linolenic acid (ALA), docosahexaenoic acid (DHA) and medium-chain triglycerides (FA-ADEK) for 12 weeks. The fatty acid profile of erythrocyte membrane phospholipids, dietary intake, plasma antioxidant vitamins and serum gamma-glutamyl transferase (GGT) were evaluated at baseline, 8 and 12 weeks after supplementation. Supplementation with FA-ADEK increased ALA, DHA and eicosapentaenoic acid (EPA) concentrations of erythrocyte membrane phospholipids by 0.040, 1.419 and 0.159%, respectively, compared with ADEK supplementation (-0.007, 0.151 and 0.002%, respectively) after 12 weeks (all P<or=0.001). Serum GGT activity decreased in patients receiving FA-ADEK compared with those receiving ADEK with a significant difference after 8 weeks. The significant change in erythrocyte membrane fatty acid pattern demonstrates the incorporation of orally administered n-3 PUFA in patients with maldigestion and malabsorption. The increase in ALA and DHA, as well as the conversion of ALA to EPA is attributed to the supplementation of sufficient amounts of ALA and DHA, respectively. Serum GGT activity decreased in response to decreased oxidative stress.

Effect of glucosamine sulfate with or without omega-3 fatty acids in patients with osteoarthritis

A total of 177 patients with moderate-to-severe hip or knee osteoarthritis (OA) were tested over a period of 26 weeks in a two-center, two-armed, randomized, double-blind, comparison study. The aim was to see if a combination of glucosamine sulfate (1500 mg/day) and the omega-3 polyunsaturated fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (group A), showed equivalence (noninferiority) or superiority as opposed to glucosamine sulfate alone (group B). The primary therapy evaluation was performed using the Western Ontario and McMaster Universities Arthrosis index (WOMAC) score. At the end of the study, a reduction in the pain score of > or =20% was required (primary target criterion) and the quantitative difference in the WOMAC subscores pain, stiffness, and function were analyzed (secondary target criteria). When a minimal pain reduction of > or =20% was chosen, there was no statistically significant difference in the number of responders between the two groups (92.2% group A, 94.3% group B). A higher responder criterion (> or =80% reduction in the WOMAC pain score) was chosen. Therefore, the frequency of responders showed a therapeutic and statistical superiority for the combination product of glucosamine sulfate and the omega-3 polyunsaturated fatty acids in patients who complied with the study protocol (group A 44%, group B 32%; P=0.044). OA symptoms (morning stiffness, pain in hips and knees) were reduced at the end of the study: by 48.5%-55.6% in group A and by 41.7%-55.3% in group B. The reduction was greater in group A than in group B. There was a tendency toward superiority shown in the secondary target criteria and concurrent variables. In the global safety evaluation, both products have been demonstrated to be very safe in long-term treatment over 26 weeks. To our knowledge, this is the first clinical trial in which glucosamine was given in combination with omega-3 fatty acids to patients with OA.

N-3 polyunsaturated fatty acids reduced morbidity and mortality in chronic heart failure

Source Citation GISSI-HF Investigators. Effect of n-3 polyunsaturated fatty acids in patients with chronic heart failure (the GISSI-HF trial): a randomised, double-blind, placebo-controlled trial. Lancet. 2008;372:1223-30. 18757090

Towards evidence-based practice via practice-based evidence: the Italian experience

Research is a fundamental tool for GPs' clinical practice. Independent research should be the answer to important questions on population needs not yet answered. To have a democratic approach, the results of the studies should be available not only to GPs but also to patients participating to the research. Research has also a formative value for investigators: a process of learning by doing. Risk and Prevention Study is a model of the 'Italian experience' in doing research in primary health care. To describe the collaboration between Centro Studi e Richerche in Medicina Generale and Mario Negri Institute in producing observational and experimental research in the setting of family medicine such the Risk and Prevention Study. Risk and Prevention Study has two main aims and two different methods: the first, to establish the effectiveness of an intensive recommended treatment and lifestyle advice in cardiovascular (CV) prevention is an observational design. The second, the efficacy of n-3 polyunsaturated fatty acid in patients with CV risk is a randomized controlled trial design. The Risk and Prevention trial has enrolled up until now 860 Italian GPs and over 12 500 high CV risk patients that will be followed during 5 years. They will visit their GP at least once a year. The first year of follow-up of the study has been completed. Relatively few patients (2.5%) have withdrawn. The treatment was well tolerated. Enrolment of large number of GPs in research appears feasible when an independent design with clear benefit for the patient's needs is offered.

Statins and n-3 fatty acid supplementation in heart failure

Heart failure is common, and leads to substantial morbidity and mortality in most regions of the world. 1 Hunt SA Abraham WT Chin MH et al. ACC/AHA 2005 guideline update for the diagnosis and management of chronic heart failure in the adult: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2005; 46: e1-e82 Summary Full Text PDF PubMed Scopus (1273) Google Scholar Medical and device therapies have been successfully developed to improve outcomes in patients with systolic heart failure. Beneficial treatments include inhibitors of the renin–angiotensin–aldosterone system and sympathetic nervous system, use of implantable cardioverter defibrillators, and cardiac resynchronisation therapy in selected patients (table). 1 Hunt SA Abraham WT Chin MH et al. ACC/AHA 2005 guideline update for the diagnosis and management of chronic heart failure in the adult: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2005; 46: e1-e82 Summary Full Text PDF PubMed Scopus (1273) Google Scholar However, not all patients with systolic heart failure qualify for or tolerate these therapies and, even with the best treatment, heart failure remains a major cause of morbidity, mortality, and health-care expenditure. No drug or device has been definitively shown to improve outcomes in patients with heart failure and preserved systolic function. 1 Hunt SA Abraham WT Chin MH et al. ACC/AHA 2005 guideline update for the diagnosis and management of chronic heart failure in the adult: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2005; 46: e1-e82 Summary Full Text PDF PubMed Scopus (1273) Google Scholar New therapies and management strategies need to be identified. Effect of n-3 polyunsaturated fatty acids in patients with chronic heart failure (the GISSI-HF trial): a randomised, double-blind, placebo-controlled trialA simple and safe treatment with n-3 PUFA can provide a small beneficial advantage in terms of mortality and admission to hospital for cardiovascular reasons in patients with heart failure in a context of usual care. Full-Text PDF Effect of rosuvastatin in patients with chronic heart failure (the GISSI-HF trial): a randomised, double-blind, placebo-controlled trialRosuvastatin 10 mg daily did not affect clinical outcomes in patients with chronic heart failure of any cause, in whom the drug was safe. Full-Text PDF

Effect of n-3 polyunsaturated fatty acids in patients with chronic heart failure (the GISSI-HF trial): a randomised, double-blind, placebo-controlled trial

Several epidemiological and experimental studies suggest that n-3 polyunsaturated fatty acids (PUFA) can exert favourable effects on atherothrombotic cardiovascular disease, including arrhythmias. We investigated whether n-3 PUFA could improve morbidity and mortality in a large population of patients with symptomatic heart failure of any cause. We undertook a randomised, double-blind, placebo-controlled trial in 326 cardiology and 31 internal medicine centres in Italy. We enrolled patients with chronic heart failure of New York Heart Association class II-IV, irrespective of cause and left ventricular ejection fraction, and randomly assigned them to n-3 PUFA 1 g daily (n=3494) or placebo (n=3481) by a concealed, computerised telephone randomisation system. Patients were followed up for a median of 3.9 years (IQR 3.0-4.5). Primary endpoints were time to death, and time to death or admission to hospital for cardiovascular reasons. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00336336. We analysed all randomised patients. 955 (27%) patients died from any cause in the n-3 PUFA group and 1014 (29%) in the placebo group (adjusted hazard ratio [HR] 0.91 [95.5% CI 0.833-0.998], p=0.041). 1981 (57%) patients in the n-3 PUFA group and 2053 (59%) in the placebo group died or were admitted to hospital for cardiovascular reasons (adjusted HR 0.92 [99% CI 0.849-0.999], p=0.009). In absolute terms, 56 patients needed to be treated for a median duration of 3.9 years to avoid one death or 44 to avoid one event like death or admission to hospital for cardiovascular reasons. In both groups, gastrointestinal disorders were the most frequent adverse reaction (96 [3%] n-3 PUFA group vs 92 [3%] placebo group). A simple and safe treatment with n-3 PUFA can provide a small beneficial advantage in terms of mortality and admission to hospital for cardiovascular reasons in patients with heart failure in a context of usual care.

CT13 PREVENTION OF ATRIAL FIBRILLATION AFTER CABG WITH OMEGA‐3 POLYUNSATURATED FATTY ACIDS

Purpose Atrial fibrillation (AF) is a common complication of cardiothoracic surgery, occurring in more than 30% of patients undergoing CABG. Postoperative AF results in thromboembolic events, haemodynamic compromise and an increase in length and cost of hospitalisation. Any intervention that reduces the incidence of postoperative AF should result in fewer complications in addition to being of important economic benefit. Increased consumption of oily fish or Omega‐3 Polyunsaturated Fatty Acid (PUFA) supplements substantially lowers the risk of sudden cardiac death and myocardial infarction both in primary and secondary prevention trials, through a reduction in fatal arrhythmias. Omega‐3 PUFAs may also play a role in the treatment of AF as shown by cell culture research, animal models and a recent prospective observation study in 5000 elderly adults. With respect to postoperative AF, a recent Italian randomized controlled study in 160 patients showed that Omega‐3 PUFA administration during hospitalisation in patients undergoing CABG reduced the incidence of postoperative AF by 54% and led to a shorter hospital stay.Methodology We have undertaken a randomized, placebo controlled, prospective trial of Omega‐3 PUFAs in patients undergoing CABG to examine its effect on the incidence of AF within 30 days and variations in length of hospital stay. We have also developed a clinically relevant measurement of the concentrations of the PUFA arachidonic acid and the omega‐3 fatty acids eicosapentaenoic acid and docosahexaenoic acid in patients with and without atrial fibrillation.Results We are presenting interim results of the first 80 patients enrolled in the trial.

Enhanced plasma values of long-chain polyunsaturated fatty acids in patients with inflammatory bowel disease

Enhanced plasma values of long-chain polyunsaturated fatty acids in patients with inflammatory bowel disease

Major depression is associated with lower omega-3 fatty acid levels in patients with recent acute coronary syndromes

Background Polyunsaturated fatty acids (PUFAs) are intrinsic cell membrane components and closely involved in neurotransmission and receptor function. Lower omega-3 levels are associated with increased risk of coronary artery disease (CAD), increases in cardiac events in CAD patients, and depression. We sought to examine relationships between depression and serum levels of omega-3 and omega-6 PUFAs in patients recovering from acute coronary syndromes (ACS). Methods We carried out a case-control study of serum PUFA levels and current major depression in 54 age- and sex-matched pairs approximately 2 months following ACS. Results Depressed patients had significantly lower concentrations of total omega-3 and docosahexaenoic acid (DHA), and higher ratios of arachidonic acid (AA) to DHA, AA to eicosapentaenoic acid (EPA), and n-3 to n-6 than controls. There were no baseline differences in any potential risk or protective factors for depression. Conclusions Results are consistent with previous reports in depressed patients without CAD, and with literature concerning omega-3 levels and risk of CAD events. Dietary, genetic, and hormonal factors may all play a role in both depression and CAD. Both prospective studies and randomized trials are needed to help clarify the interrelationships.

N-3 Fatty acids and their role in nephrologic practice

During the past year, a newly reported clinical trial has strengthened the argument for recommending daily treatment with n-3 polyunsaturated fatty acids in patients with immunoglobulin A nephropathy (the most common form of primary glomerulonephritis in the world) who are at high risk for progression of renal disease. Studies are underway that involve a combination of cyclosporine A, a commonly prescribed immunosuppressive agent in solid-organ transplantation, with a high-potency n-3 polyunsaturated fatty acid to reduce cyclosporine toxicity. Two studies reported during the past year show promise that dietary supplementation with n-3 polyunsaturated fatty acids will substantially decrease vascular access graft thrombosis in patients receiving maintenance hemodialysis, and may reduce hypercalciuria in patients who suffer from kidney stones.

Heart rate variability and n-3 polyunsaturated fatty acids in patients with diabetes mellitus.

Dietary n-3 polyunsaturated fatty acids (PUFA) derived from fish may reduce the incidence of sudden cardiac death (SCD). The aim of the present study was to examine associations between n-3 PUFA and 24-h heart rate variability in patients with type 1 and type 2 diabetes mellitus (DM). Observational study. The out-patient's diabetic clinic at Hjørring Hospital, Hjørring, Denmark. Forty-three patients with type 1 DM and 38 patients with type 2 DM. The patients fulfilled a food-questionnaire regarding fish consumption, whilst the content of n-3 PUFA in platelets was measured and 24-h heart rate variability (HRV) was obtained. The patients fish consumption was strongly related to their content of n-3 PUFA in platelets. Furthermore, in patients with type 1 DM a close positive association was found between the content of n-3 PUFA in platelets and 24-h HRV. This association was not significant in patients with type 2 DM. The positive association between n-3 PUFA in platelets and HRV may indicate a beneficial effect of n-3 PUFA on HRV in patients with type 1 DM. Further studies are warranted to clarify whether supplementation with n-3 PUFA reduce the risk of SCD amongst patients with DM.

EFFECT OF SYSTEMIC ADMINISTRATION OF ISOTRETINOIN ON BLOOD LIPIDS AND FATTY ACIDS IN ACNE PATIENTS

In many studies, an increase in total cholesterol and triglycerides with isotretinoin therapy have been shown and investigators have commented on potential cardiovascular risk. A low intake of linoleic acid, the main essential fatty acid in man, may act as an independent risk factor for coronary heart disease. In vitro etretin alters both the incorporation of extracellular fatty acids into cell membranes and the fatty acid composition of the cell membrane itself. It is, therefore, important to establish whether isotetinoin has any effect on the metabolism of polyunsaturated fatty acids. The effect of treatment with isotretinoin for 4 months on the metabolism of polyunsaturated fatty acids in patients with acne was assessed. Quantitative total cholesterol and triglycerides as well as plasma phospholipid, triglycerides, and cholesteryl ester fatty acids were measured in 12 patients and red cell phosphatidylethanolamine, phosphatidylcholine, and phosphatidylinositol fatty acids were measured in 13 patients before and after isotretinoin therapy. There was a significant increase in the concentrations of cholesterol (P < 0.02) and triglycerides (P < 0.04) during treatment. There was no significant difference is plasma phospholipids, triglycerides, and cholesterol esters, or in the red cell phosphatidylethanolamine, phosphatidylcholine, and phosphatidylinositol during isotretinoin therapy. This study failed to demonstrate any effect of isotretinon on the metabolism of polyunsaturated fatty acids. There was a significant increase in total cholesterol and triglyceride levels following isotretinoin therapy supporting the findings of many previous studies.

Long-term metabolic effects of n-3 polyunsaturated fatty acids in patients with coronary artery disease

The long-term metabolic effects of n-3 fatty acids were studied in patients with coronary artery disease. They were investigated before and 9 mo after bypass surgery. After postoperative randomization, 260 patients received 4 g fish-oil concentrate/d (approximately 3.4 g eicosapentaenoic and docosahexaenoic acids/d), whereas 251 patients comprised the control group. No group differences in the intake of energy and nutrients, apart from n-3 fatty acids, were discerned from dietary records. Compliance was affirmed by analyses of serum phospholipid fatty acids. Serum triglyceride concentrations were lowered by 19.1% in the fish-oil group, but no influence on the concentrations of cholesterol or apolipoproteins A-I and B-100 was seen. The concentrations of plasma glucose and serum insulin and C-peptide were not influenced by fish oil. The activity of liver enzymes increased slightly, but significantly, in the fish-oil group, whereas no group difference in the serum concentrations of thiobarbituric acid-reactive substances was observed. Thus, no adverse metabolic effects of long-term fish-oil supplementation assumed to be of clinical importance were seen.

Blood polyunsaturated fatty acids in patients with peroxisomal disorders. A multicenter study

The purpose of the study was to compare the polyunsaturated fatty acid (PUFA) status in patients with X-linked adrenoleukodystrophy or adrenomyeloneuropathy (X-ALD/AMN) with that in disorders of peroxisome biogenesis (PB). Total fatty acids and plasmalogens were quantified in plasma and red cells from 28 patients with X-ALD/AMN, 26 patients with generalized peroxisomal disorders, and 37 controls. Total fatty acid methyl esters and plasmalogen dimethyl acetals were obtained by direct transmethylation and separated by capillary column gas chromatography. The results confirm previous findings in that docosahexaenoic acid (DHA, 22:6n-3) was greatly decreased in both plasma and erythrocytes from patients with PB disorders. When nutritional conditions were adequate, patients with X-ALD/AMN had normal levels of DHA. A highly significant positive correlation was found between the levels of DHA and those of plasmalogens in peroxisomal patients. As in other tissues, the parent n-6 fatty acid, linoleic acid (LA, 18:2n-6) was significantly increased in red cells from PB patients, whereas arachidonic acid (20:4n-6) was virtually within normal limits. In clear contrast to red cells and other tissues, arachidonate was significantly lower in plasma from PB patients. The decrease in plasma arachidonate and the high tissue levels of LA suggest a defect of delta 6 desaturase and/or delta 5 desaturase in PB patients. The n-6 fatty acids were normal in X-ALD/AMN patients. The present data show that X-ALD/AMN patients do not have the profound PUFA alterations that PB patients have, at least in blood.

Postheparin lipolytic activity and plasma lipoprotein response to ω-3 polyunsaturated fatty acids in patients with primary hypertriglyceridemia

The hypotriglyceridemic action of omega-3 (n-3) fatty acids is attributed primarily to reduction in hepatic triglyceride synthesis and reduced secretion of very-low-density lipoproteins (VLDLs). However, increased catabolism of triglyceride-rich lipoproteins was reported and could be due to increased availability of peripheral lipoprotein lipase (LPL) or hepatic lipase (HL). In this study plasma lipoproteins and postheparin activities of LPL and HL were determined in 12 patients with primary hypertriglyceridemia before and during isocaloric substitution of omega-3 fatty acids (10 g/d) for 4 wk. Omega-3 polyunsaturates resulted in 53% and 61% reductions in plasma triglyceride and VLDL-cholesterol concentrations, respectively (P less than 0.0001). However, low-density-lipoprotein (LDL)-cholesterol concentrations increased by 26% (P less than 0.001). Activities of postheparin LPL and HL essentially remained the same. Thus, in patients with primary hypertriglyceridemia, reduction in plasma triglyceride concentrations and increase in LDL-cholesterol concentrations mediated by omega-3 polyunsaturates seem to occur without an increase in LPL or HL activities.