High PUFAs May Slow Emphysema Progression, Lower Pulmonary Disease Risk

After careful consideration, the American Thoracic Society canceled its annual meeting that was to take place in Philadelphia, Pennsylvania from May 15-20, because of the ongoing coronavirus disease 2019 (COVID-19) pandemic. Although the live events will not proceed as planned, our readers can still find coverage of research that was scheduled to be presented at the meeting. A virtual event is being planned for later this year.

High plasma omega-3 polyunsaturated fatty acid (n-3 PUFA) levels have been shown to be associated with a slower progression of percent emphysema and a decreased risk for chronic lower respiratory disease, according to results of analysis intended to be presented at the American Thoracic Society (ATS) International Conference. (Select research is slated to be presented in a virtual format later this year.)

Using data from the longitudinal Multi-Ethnic Study of Atherosclerosis (MESA), researchers analyzed whether higher plasma n-3 PUFAs were linked to a change in percent emphysema on computed tomography (CT), a slower decline in lung function, and a lower likelihood of developing chronic lower respiratory disease.

A total of 6814 adult patients aged 45 to 84 years were enrolled in the MESA Lung Study, which was initiated between the years 2000 and 2002. The most recent examination occurred between 2016 and 2018. Overall, 6573 of the participants had baseline phospholipid fatty acid levels measured via the use of baseline plasma samples. From 2000 to 2007, the participants underwent cardiac CT scans, and from 2010 to 2018, patients received full-lung CT scans, at which time percent emphysema (< -950 Hounsfield Units) was evaluated. Follow-up examinations took place between 2004 and 2018, at which time spirometry was performed.

Relationships between n-3 PUFA levels and change in percent emphysema, and associations of n-3 PUFA concentrations with spirometry, were examined with the use of linear mixed models. Adjustments were made for age, sex, race/ethnicity, smoking status, cigarettes/d, cigarette pack-years, height, weight, education, insurance type, 18:2 trans fat level, chronic obstructive pulmonary disease genetic risk score (COPD GRS), as well as primary components for ancestry, baseline ozone, nitric oxide, and temperature exposure. In the analysis, PUFA levels were expressed as percent of total fatty acids.

Results of the study reported mean plasma docosahexaenoic (DHA), eicosapentaenoic (EPA), and docosapentaenoic acid (DPA) levels of 3.8%±1.5%, 0.9%±0.8%, and 0.9%±0.2%, respectively. Over a mean follow-up of 12.0±4.1 years, higher total n-3 plasma levels (DHA+EPA+DPA) were associated with a slower percent of progression of emphysema in a model that was adjusted for covariates and COPD GRS (-0.51% relative change in percent emphysema per log-transformed total n-3 increment; 95% CI, -0.99 to -0.03). These associations were stronger in ever smokers compared with never smokers (P =.01 for smoking interaction).

Additionally, n-3 PUFA levels were not associated with spirometry. Higher total n-3 PUFA levels were linked to a decreased risk for occurrence of a chronic lower respiratory disease event (adjust hazard ratio, 0.53 per log-transformed total n-3 increment; 95% CI, 0.43-0.67). Moreover, in terms of chronic lower respiratory disease events, n-3 PUFA concentrations were associated with a decreased risk for COPD-related events (adjusted hazard ratio, 0.45; 95% CI, 0.31-0.66), with the associations significantly stronger in ever smokers (P =.04 for smoking interaction).

The investigators concluded that the findings from this study demonstrated that the use of n-3 PUFAs may be protective in patients with COPD and individuals with other chronic lower respiratory lung diseases.

Reference

Kim J, Balte P, Hoffman EA, et al. Associations of plasma omega-3 fatty acid levels with longitudinal change in percent emphysema, spirometry, and chronic lower respiratory disease events: the MESA Lung Study. Am J Respir Crit Care Med. 2020;201:A4489.

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