A new study from a team of investigators at the University of California, San Francisco (UCSF) has just published evidence showing that individuals diagnosed with peripheral artery disease (PAD) have a lower Omega-3 Index compared to those who don’t have the disease. Findings from the new study were published recently in Lipids through an article titled “Peripheral Artery Disease Is Associated with a Deficiency of Erythrocyte Membrane n‐3 Polyunsaturated Fatty Acids.”
PAD is a disease that affects the blood vessels outside the heart and brain. Evidence from other studies suggests that omega-3s affect many steps of the atherosclerotic process. More specifically, they improve endothelial function, promote vasodilatation through relaxation of smooth muscle cells, exert antioxidant, anti-inflammatory, and antithrombotic actions, delay development of plaques and increase their stability, and decrease wall stiffening.
Since PAD is often considered atherosclerosis of the leg arteries, researchers in this study believe that patients with PAD may have an omega-3 fatty acid deficiency.
“The objective of this study is to compare erythrocyte membrane fatty acid (FA) content between patients with PAD and controls. We conducted a cross‐sectional study of 179 vascular surgery outpatients (controls, 34; PAD, 145),” the authors wrote.
The research team found that the Omega-3 Index was significantly lower in the PAD patients than the controls (5% vs 6%). When they controlled for other patient characteristics that might have influenced these findings (like age, smoking, blood pressure, diabetes, drugs, etc.), the Omega-3 Index was still lower in the cases vs. the controls.
“A blood sample was drawn and the erythrocyte FA content was assayed using capillary gas chromatography. We calculated the ratio of the n‐3 polyunsaturated fatty acids (PUFA) eicosapentaenoic acid (EPA) to the n‐6 PUFA arachidonic acid (ARA) as well as the omega‐3 index (O3I), a measure of erythrocyte content of the n‐3 PUFA, EPA, and docosahexaenoic acid (DHA), expressed as a percentage of total erythrocyte FA,” the authors stated. “Compared with controls, patients with PAD smoked more and were more likely to have hypertension and hyperlipidemia (p < 0.05). Patients with PAD had a lower mean O3I (5.0 ± 1.7% vs 6.0 ± 1.6%, p < 0.001) and EPA:ARA ratio (0.04 ± 0.02 vs 0.05 ± 0.05, p < 0.001), but greater mean total saturated fats (39.5 ± 2.5% vs 38.5 ± 2.6%, p = 0.01). After adjusting for several patient characteristics, comorbidities, and medications, an absolute decrease of 1% in the O3I was associated with 39% greater odds of PAD (odds ratio [OR] 1.39, 95% confidence interval [CI] 1.03–1.86, and p = 0.03).”
In the final analysis, the researchers reported that for every 1% unit reduction in the Omega-3 Index, the odds of being a PAD patient increased by 39%, and for every additional pack-year of smoking the odds of being a PAD case increased by 4%.
“It is likely that the lower inflammatory burden associated with a higher Omega-3 Index may be part of the explanation for these results,” concluded study author Bill Harris, PhD, president and CEO of OmegaQuant Analytics. “Whether long-term use of omega-3 supplements and/or increased consumption of oily fish could prevent the development of PAD should be examined in future studies.”