Randomized controlled trial of gamma-linolenic acid and eicosapentaenoic acid in peripheral arterial disease

Background and Aims: epidemiological studies suggest polyunsaturated fatty acids protect against the development of atherosclerosis. The aim of this study was to perform a randomized controlled trial of gamma-linolenic and eicosapentaenoic acids in patients with lower limb atherosclerosis. Main outcome measures were: cholesterol and lipoprotein concentrations; haemostatic and rheological variables; the ankle brachial pressure index; walking distance; and cardiovascular events and death. Methods: 120 men and women with stable intermittent claudication were randomized to 2 years treatment with either a combination of gamma-linolenic and eicosapentaenoic acids, or placebo. Results: 39 (65.0%) of those taking fatty acids and 36 (60.0%) of those taking placebo completed the trial. Lipid concentrations did not differ significantly during the trial. In those taking fatty acids, haematocrit was significantly higher than in the placebo group after 6 months (46.1% compared with 44.6%, P ≤ 0.01), and systolic blood pressure was significantly lower after 2 years (150 mmHg compared with 161.8 mmHg, ≤ 0.05). There was no difference in walking distance, but there was a small reduction in non-fatal coronary events in the fatty acid group (10% compared with 15%, P> 0.05). Conclusions: a combination of polyunsaturated fatty acids produced a statistically significant reduction in systolic blood pressure, but no other significant benefits on risk factors. The trend towards fewer coronary events in those taking fatty acids warrants further investigation.