Higher Plasma Omega-3 Levels Are Associated with Improved Exacerbation Risk and Respiratory-Specific Quality of Life in COPD

Background: Omega - 3 polyunsaturated fatty acids (PUFAs) have been associated with systemic anti - inflammatory responses. Dietary intake of omega - 3 PUFAs eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) has also been associated with lower chronic obstructive pulmonary disease (COPD) morbidity using self - report food frequency questionnaires. Objective: The objective of this study was to investigate the relationship between measured PUFA intake using plasma EPA+DHA levels and COPD morbidity. Methods: Former smokers with moderate - to - severe COPD living in low - income communities were enrolled in a 6 - month prospective cohort study. Participants completed standardized questionnaires, spirometry, and plasma samples at 3 - month intervals. Total plasma PUFAs were analyzed using gas chromatography/mass spectrometry for DHA and EPA concentrations. Linear or logistic mixed model regression was used to evaluate EPA+DHA's and COPD morbidity's association, accounting for demographics, lung function, pack years, comorbidities, and neighborhood poverty. Results: A total of 133 plasma EPA+DHA samples from 57 participants were available. Participants exhibited average plasma EPA and DHA levels of 14.7 +/- 7.3 mu g/mL and 40.2 +/- 17.2 mu g/mL, respectively, across the 3 clinic visits. Each standard deviation increase in EPA+DHA levels was associated with 2.7 points lower St George's Respiratory Questionnaire score (95% confidence interval [CI] - 5.2, - 0.2) and lower odds of moderate exacerbation (odds ratio 0.4; 95% CI 0.2, 0.9), but lacked significant association with the COPD Assessment Test score (95% CI - 2.4, 0.8), modified Medical Research Council dyspnea scale (95% CI - 02, 0.2), or severe exacerbations (95% CI 0.3, 1.4). Conclusion: Plasma EPA+DHA levels are associated with better respiratory - specific quality of life and lower odds of moderate exacerbations in patients with moderate - to - severe COPD. Further research is warranted to investigate the efficacy of an omega - 3 dietary intervention in the management of COPD morbidities.