Effect of omega-3 fatty acids on kidney function after myocardial infarction: the Alpha Omega Trial

Abstract

Background and objectives: Kidney function gradually decreases with age, and myocardial infarction accelerates this deterioration. Omega-3 (n-3) fatty acids may slow down the decline of kidney function. The effect of marine and plant-derived n-3 fatty acids on kidney function in patients after myocardial infarction was examined.

Design, setting, participants, & measurements: In the Alpha Omega Trial, 2344 patients with history of myocardial infarction ages 60-80 years old (81% men) were randomized to one of four trial margarines. The patients received an additional targeted amount of 400 mg/d eicosapentaenoic acid and docosahexaenoic acid, 2 g/d α-linolenic acid, eicosapentaenoic acid-docosahexaenoic acid plus α-linolenic acid, or placebo for 40 months. Serum cystatin C and serum creatinine were assessed at baseline and after 40 months. Creatinine-cystatin C-based GFR was estimated with the Chronic Kidney Disease Epidemiology Collaboration equation.

Results: Patients consumed 19.9 g margarine/d, providing an additional 239 mg/d eicosapentaenoic acid with 159 mg/d docosahexaenoic acid, 1.99 g/d α-linolenic acid, or both in the active treatment groups. After 40 months, compared with baseline, mean (±SD) creatinine-cystatin C-based GFR was -6.9 (±12.6), -4.8 (±13.4), -6.2 (±12.8), and -6.0 (±13.0) ml/min per 1.73 m(2) in the placebo, eicosapentaenoic acid-docosahexaenoic acid, α-linolenic acid, and eicosapentaenoic acid-docosahexaenoic acid plus α-linolenic acid groups, respectively. After 40 months, in patients receiving eicosapentaenoic acid-docosahexaenoic acid compared with placebo, the decline in creatinine-cystatin C-based GFR was 2.1 less (95% confidence interval, 0.6 to 3.6; P<0.01) ml/min per 1.73 m(2); other comparisons were not statistical significant. Odds ratios (95% confidence intervals) of incident CKD (<60 ml/min per 1.73 m(2)) and rapid decline of kidney function (≥3 ml/min per year) for eicosapentaenoic acid-docosahexaenoic acid compared with placebo were 0.83 (0.58 to 1.18) and 0.85 (0.67 to 1.08), respectively.

Conclusions: Long-term supplementation with 400 mg/d eicosapentaenoic acid-docosahexaenoic acid provides a small beneficial effect on kidney function in patients with a history of myocardial infarction.

Trial registration: ClinicalTrials.gov NCT00127452.

Keywords: CKD; cardiovascular disease; clinical trial; nutrition; omega-3 fatty acids.

Copyright © 2014 by the American Society of Nephrology.

Figures

Figure 1.

Flow chart of the 2344 patients in the Alpha Omega Trial: randomization and follow-up. ALA, α-linolenic acid; DHA, docosahexaenoic acid; EPA, eicosapentaenoic acid.

Figure 2.

Effect of intervention of n-3 fatty acids on yearly decline in creatinine–cystatin C-based kidney function in 2344 patients of the Alpha Omega Trial according to treatment group. Yearly mean changes of eGFRcr-cysC compared with baseline with 95% confidence intervals. P values were obtained by means of the t test for independent samples using the placebo group as the reference. eGFRcr-cysC, creatinine–cystatin C-based eGFR; n-3, Omega-3.