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

Abstract

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 cent) of those taking fatty acids and 36 (60.0 cent) 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 cent compared with 44.6 cent, 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 cent compared with 15 cent, 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.