1. ¹Department of Clinical Chemistry, Central Hospital in Rogaland, Stavanger, Norway
2. ²Department of Medicine, Central Hospital in Rogaland, Stavanger, Norway
3. ³Department of Medicine, University of Tromsoe, Norway

Correspondence: H Grundt, Department of Internal Medicine, Central Hospital in Rogaland, POB 8100, 4068 Stavanger, Norway. E-mail: heidi@madlalia.no

Guarantor: H Grundt.

Received 8 September 2002; Revised 2 December 2002; Accepted 19 December 2002.

Abstract

Objective: To assess the oxidative burden of a highly concentrated compound of n-3 PUFAs as compared to corn oil by measuring thiobarbituric acid–malondialdehyde complex (TBA–MDA) by HPLC. We also studied the influence on TBA–MDA of statins combined with n-3 PUFAs or corn oil.

Design: A prospective, randomised, double-blind, controlled study.

Setting: One hospital centre in Stavanger, Norway.

Subjects: A total of 300 subjects with an acute myocardial infarction (MI).

Interventions: Gelatine capsules, containing 850–882 mg EPA and DHA as concentrated ethylesters, or 1 g of corn oil, were ingested in a dose of two capsules twice a day for at least 1 y. Alpha-tocopherol (4 mg) was added to all capsules to protect the PUFAs against oxidation.

Results: After 1 y TBA–MDA increased modestly in the n-3 PUFA group (n=125), as compared to the corn oil group (n=130), P=0.027. Multiple linear regression analyses of fatty acids in serum total phospholipids (n=56) on TBA–MDA measured after 12 months intervention, showed no dependency. Performing best subsets regression, serum phospholipid concentration of arachidonic acid (20:4 n-6 PUFA) was identified as a predictor of TBA–MDA at 12 months follow-up, P=0.004.

We found no impact of statins on TBA–MDA.

Conclusion: TBA–MDA increased modestly after long-term intervention with n-3 PUFAs compared to corn oil post-MI, suggesting biological changes induced by n-3 PUFAs, rather than simply reflecting their concentration differences. The peroxidative potential of n-3 PUFAs was not modified by statin treatment.

Sponsorship: Pharmacia A/S and Pronova A/S, Norway.