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No funding was obtained specifically for this systematic review. JE is supported by a Food Advancement through Science and Training (FAST) scholarship through the National Sciences and Engineering Research Council’s Collaborative Research and Training Experience (CREATE) program. The authors declare no conflicts of interest.
An expert in vascular and metabolic disease (JE) led the review team, which included a panel of content experts from multiple fields: vascular physiology (PZ), lipid nutrition (CGT), and research methodology (RZ, AMAS). All authors assisted in formulating the review question, CF assisted with developing the search strategies, RZ and AMAS guided the review methods, and AY assisted with screening and data extraction throughout the review process. JE drafted the manuscript with input from all other authors. All authors read and approved the final manuscript.
Individuals with peripheral arterial disease are at higher risk for cardiovascular events than the general population. While supplementation with omega-3 polyunsaturated fatty acids (PUFA) has been shown to improve vascular function, it remains unclear if supplementation decreases serious clinical outcomes. We conducted a systematic review and meta-analysis to determine whether omega-3 PUFA supplementation reduces the incidence of cardiovascular events and complications in adults with peripheral arterial disease.
We searched five electronic databases (MEDLINE, EMBASE, CENTRAL, Scopus and the International Clinical Trials Registry Platform) from inception to 6 December 2013 to identify randomized trials of omega-3 PUFA supplementation (from fish or plant oils) that lasted ≥12 weeks in adults with peripheral arterial disease. No language filters were applied. Data on trial design, population characteristics, and health outcomes were extracted. The primary outcome was major adverse cardiac events; secondary outcomes included myocardial infarction, cardiovascular death, stroke, angina, amputation, revascularization procedures, maximum and pain-free walking distance, adverse effects of the intervention, and quality of life. Trial quality was assessed using the Cochrane Risk of Bias tool.
Of 741 citations reviewed, we included five trials enrolling 396 individuals. All included trials were of unclear or high risk of bias. There was no evidence of a protective association of omega-3 PUFA supplementation against major adverse cardiac events (pooled risk ratio 0.73, 95% CI 0.22 to 2.41, I 2 75%, 2 trials, 288 individuals) or other serious clinical outcomes. Adverse events and compliance were poorly reported.
Our results showed that insufficient evidence exists to suggest a beneficial effect of omega-3 PUFA supplementation in adults with peripheral arterial disease with regard to cardiovascular events and other serious clinical outcomes.