Effect of Omega-3 Fatty Acids on Chronic Obstructive Pulmonary Disease: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Abstract

Purpose

Omega-3 fatty acid is an emerging hotspot on anti-inflammation and chronic obstructive pulmonary disease (COPD) is known as a chronic inflammatory disease. The effect of Omega-3 fatty acid supplement on patients with COPD remains mixed for insufficient evidence. This systematic review and meta-analysis is based on neat randomized controlled trials trying to give a clearer impression on the effect of Omega-3 on patients with COPD.

Methods

This systematic review and meta-analysis was conducted following the Preferred Reporting Items for Systematic Review and Meta-analyses (PRISMA) statements. Randomized clinical trials (RCTs) published in electronic databases including Medline, Embase, Cochrane Library, ClinicalTrials.gov and China National Knowledge Infrastructure (CNKI) by May 10, 2021 were searched. Data extracted from 6 predetermined domains (nutritional condition, lipid composition, inflammatory biomarker, lung function, physical endurance and quality of life [QoL]) were reviewed and analyzed.

Results

A total of 8 RCTs evaluating 418 patients (age, mean [SD] = 67.3 [10.2] years) were included. Statistical differences were found in 3 parameters of 3 domains – weight (Wt) (0.25 [95% CI, 0.02 to 0.48], P = 0.03) in nutritional condition, low-density lipoprotein (LDL) (0.70 [95% CI, 0.30 to 1.10], P = 0.00) in lipid composition and interleukin-6 (IL-6) level (−0.32 [95% CI, −0.60 to −0.05], P = 0.02) in inflammatory biomarker – while no significant difference was found in lung function, physical endurance or QoL.

Conclusion

Comparing with placebo, Omega-3 intake was associated with more weight-gaining, LDL increase and IL-6 reduction. These results should be interpreted cautiously for the quality and quantity of available evidence are limited.

Keywords:

• COPD
• omega-3 fatty acids
• systematic review and meta-analysis

Abbreviations

ARDS, acute respiratory distress syndrome; BMI, body mass index; CI, confidence interval; CNKI, China National Knowledge Infrastructure; COPD, chronic obstructive pulmonary disease; CRP, C-reactive protein; DLCO, carbon monoxide diffusing capacity; FEV₁, forced expiratory volume in 1 second; FFMI, fat-free mass index; FVC, forced vital capacity; HDL, high density lipoprotein; IL-6, interleukin-6; LDL, low density lipoprotein; MV, mechanical ventilated; NF-ϰB, nuclear factor kappa B; PRISMA, Preferred Reporting Items for Systematic Review and Meta-analyses; QoL, quality of life; RCT, randomized controlled trial; SD, standard difference; SMD, standardized mean difference; TG, triglycerides; TNF-α, tumor necrosis factor-α; VA, alveolar ventilation; VLDL, very low-density lipoprotein; Wt, weight.

Consent for Publication

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Author Contributions

All authors made a significant contribution to the work reported, whether that is in the conception, study design, execution, acquisition of data, analysis and interpretation, or in all these areas; took part in drafting, revising or critically reviewing the article; gave final approval of the version to be published; have agreed on the journal to which the article has been submitted; and agree to be accountable for all aspects of the work.

Disclosure

The authors report grants from Science and Technology Projects of Gansu Province, during the conduct of the study. There are no other conflicts of interest in this work.

Additional information

Funding

This work was supported by the Science and Technology Projects of Gansu Province (grant number 18JR3RA344). Funder had no role in the design of the study, the collection and analysis of the data, or the preparation of the manuscript.