Effects of n-3 PUFA on endothelial function in patients with peripheral arterial disease: a randomised, placebo-controlled, double-blind trial

As only limited evidence is available for potential benefits of n-3 PUFA supplementation in patients with peripheral arterial disease (PAD), we studied the effects of 4 g n-3 PUFA on endothelial function and inflammatory markers. Seventy patients with stable PAD classified as Rutherford stage 2 or 3 and good control of cardiovascular factors were randomised to receive either 4 g n-3 PUFA or placebo daily for 3 months in a double-blind fashion. Primary endpoint was endothelial function assessed by flow-mediated vasodilation (FMD). In addition, ankle-brachial index, maximum and pain-free walking distances were determined. Lipid parameters including the omega-3 index reflecting n-3 PUFA intake as well as pro-inflammatory, endothelial and platelet activation markers were measured over the same time interval. After 3 months of treatment with 4 g n-3 PUFA daily, a significant improvement of FMD was observed compared with placebo (n-3 PUFA, median Δ 3·7 (interquartile range (IQR) -1·8, 7·1) % v. placebo, Δ -0·5 (IQR -6·5, 3·0) %, P = 0·01 between the groups). After a 3-month washout period, this benefit was not sustained (n-3 PUFA, median Δ 0·6 (IQR -2·2, 5·6) % v. placebo, Δ -0·9 (IQR -6·6, 6·7) %, P = 0·20). In response to n-3 PUFA, an improvement of lipid parameters with a pronounced increase in the omega-3 index was seen. No changes were found for other parameters. In conclusion, in patients with PAD, 4 g/d n-3 PUFA improved cardiovascular risk in PAD patients, which needs testing in large-scale trials.