|Nutrition Evidence Library|
Erkkila AT, Lehto S, Pyorala K, and Uusitupa MIJ. N-3 fatty acids and five-year risks of death and cardiovascular disease events in patients with coronary artery disease. Am J Clin Nutr 2003 July; 78 (1): 65-71.
PubMed ID: 12816772
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Research Design and Implementation Rating:
POSITIVE: See Research Design and Implementation Criteria Checklist below.
To investigate whether a high proportion of n-3 fatty acids in serum lipids would be associated with reduced risks of death and coronary events in patients with established CAD.
Finnish cohort of EUROASPIRE study with clinically-established CAD, aged <71 at time of admission to hospital in 1991-94. The subjects fell into one of the following four criteria: First elective or emergency coronary artery bypass grafting (CABG), first elective or emergency percutaneous transluminal coronary angioplasty (PCTA) but no previous CABG, first or recurrent acute myocardial infarction (AMI) but with no previous CABG or PTCA or admitted with symptoms compatible with acute myocarial ischemia (AMIA) but in whom the diagnosis of AMI could not be confirmed and who no previous CABG, PCTA, or AMI.
Description of Study Protocol:
Data Collection Summary:
The food records were analyzed for total calories, total fat, saturated, monounsaturated and polyunsaturated fat, cholesterol, protein, carbohydrate, fiber and alcohol.
Blood was analyzed for LDL, HDL, cholesterol, triacylglycerol, glucose, cholesteryl esters, phospholipids and fatty acid methyl esters.
Description of Actual Data Sample:
285 men and 130 women with CAD, mean age 61 years, range 33-74 years.
Summary of Results:
During the five-year follow-up, 36 patients died, 21 had MIs, and 12 had strokes. The patients who died were significantly older at baseline than those who survived and had significantly higher serum TC, LDL-C and TG concentrations, as well as higher intakes of fat and saturated fat and lower intakes of fiber.
Fish intake was divided into three categories: No intake (0 grams per day), and below and above median consumption (57 grams per day). Fish intake tended to be associated with low risks of death and of the combined endpoint of CVD death, AMI or stroke.
High proportions of ALA, EPA and DHA in CEs tended to be associated with a low risk of death. The relative risks of death adjusted for CVD risk factors for subjects in the highest tertile of fatty acids in CEs compared with those in the lowest tertile were 0.33 (95% CI: 0.11, 0.96) for a-linolenic acid, 0.33 (0.12, 0.93) for EPA, and 0.31 (0.11, 0.87) for DHA (P for trend =0.063, 0.056, and 0.026, respectively). A high proportion of EPA in CEs was associated with a low risk in CAD death.
Fish intake correlated with proportions of EPA (r=0.568, P<0.01) and DHA (r= 0.545, P<0.01) in serum CEs. Compared with no consumption, consumption of fish tended to be associated with a lower risk of death [1-57 grams per day, relative risk =0.50 (0.20, 1.28); >57 grams per day, relative risk =0.37 (0.14, 1.00); P for trend =0.059].
The main finding of the present study is that proportions of ALA, EPA and DHA in serum CEs are associated with a reduction in the risk of all-cause mortality. The associations between EPA and DHA and the risk of death were confirmed by the reduced risk observed in the subjects who ate fish or who had high proportions of EPA and DHA in serum phospholipids. The associations of n-3 fatty acids with combined fatal and non-fatal CVD events were, however, not significant. In conclusion, ALA, EPA and DHA are nutritional factors that could potentially reduce the risk of death in patients with CAD. Furthermore, this benefit can be obtained through the intake of foods and without the intake of supplements.
Author noted that the size of the study cohort may have limited the power of the statistical analysis, and since virtually all the patients were taking cardiovascular drugs, this could have confounded the observed associations. Dietary intakes and serum lipid fatty acid profiles measured only at baseline, and it is possible that dietary changes may have occurred during the follow-up period.
Copyright American Dietetic Association (ADA).