Can fish oil supplementation improve endothelial function in asymptomatic offspring of patients with peripheral arterial disease

Correspondence: J Ian Spark Department of Vascular Surgery, Flinders Medical Centre, Flinders Drive, Bedford Park, Adelaide, SA 5042, Australia Tel +618 8204 5445 Fax +618 8204 7106 Email ian.spark@health.sa.gov.au Background: Peripheral arterial disease affects 10%–25% of adults aged .55 years, and while a multitude of risk factors exist, one key influence is genetics. Rather than awaiting the onset of debilitating symptoms, interventions that target high-risk individuals and prevent or delay the onset of symptoms would have widespread impact. The aim of this study is to implement a 12-week fish oil intervention (10 mL/day containing approximately 1.5 g of eicosapentaenoic acid and 1 g of docosahexaenoic acid), with the intention of improving endothelial function, inflammation, and lipid status in a high-risk population, ie, those with impaired endothelial function and a parent with symptomatic peripheral arterial disease. Methods: This is a parallel-group, double-blind, randomized controlled trial involving administration of fish oil containing either about 1.5 g of docosahexaenoic acid and 1 g of docosahexaenoic acid (intervention) or about 0.15 g of eicosapentaenoic acid and about 0.1 g of docosahexaenoic acid for 12 consecutive weeks (control). The participants are 100 offspring of adults with diagnosed peripheral arterial disease who themselves have an ankle-brachial pressure index $0.9 but impaired endothelial function according to peripheral arterial tonometry. Measures performed at baseline and at 6 and 12 weeks include flow-mediated dilatation, Creactive protein, absolute neutrophil and lymphocyte counts, tumor necrosis factor-α, interleukin-1β, and interleukin-6 levels, thromboxane and prostacyclin, lipid status, and homocysteine, nitrite, and nitrate levels. Participants will be phoned fortnightly to monitor adherence and side effects, while participants will maintain a diary of fish oil consumption on a daily basis, and fish oil returned will be measured to confirm adherence. Participants will complete validated surveys to determine background diet and physical activity levels. Discussion: This study will examine the effectiveness of a moderate-dose fish oil intervention in reversing endothelial dysfunction in asymptomatic offspring of patients with peripheral arterial disease. It provides the opportunity to delay the progression of peripheral arterial disease using a cheap and readily available dietary supplement that has minimal side effects compared with synthetic vasoactive pharmacological medications.