Dietary polyunsaturated fatty acid intake and all-cause and cardiovascular mortality in patients with COPD.

Background: Chronic obstructive pulmonary disease (COPD) patients face increased mortality risk, particularly from cardiovascular causes. While polyunsaturated fatty acids (PUFAs) have shown cardiovascular benefits in general populations, their impact on COPD mortality remains unexplored.

Methods: This prospective cohort study analyzed 2,102 COPD patients from NHANES (1999-2018). PUFA intake was assessed through 24-hour dietary recalls and categorized into tertiles. Associations with all-cause and cardiovascular mortality were evaluated using Cox regression models, restricted cubic splines (RCS), and weighted quantile sum (WQS) regression. Comprehensive subgroup and sensitivity analyses confirmed result robustness.

Results: During 9.08 years of follow-up, 603 deaths (28.7%) occurred, including 190 (9.0%) from cardiovascular disease. Compared to the lowest tertile, the highest tertile of total PUFA (HR: 0.70, 95% CI: 0.53-0.91), N-3 PUFA (HR: 0.67, 95% CI: 0.52-0.87), and N-6 PUFA (HR: 0.74, 95% CI: 0.57-0.97) intake was associated with lower all-cause mortality. For cardiovascular mortality, higher intake of total PUFA (HR: 0.55, 95% CI: 0.33-0.90), N-3 PUFA (HR: 0.56, 95% CI: 0.36-0.89), and N-6 PUFA (HR: 0.57, 95% CI: 0.34-0.93) showed significant protective effects. RCS analyses revealed non-linear associations with significant threshold effects. WQS analysis identified two plant-derived PUFA-α-linolenic acid (ALA) and linoleic acid (LA) as the primary contributors to mortality reduction. All sensitivity analyses confirmed the stability and consistency of our main findings.

Conclusions: Higher dietary PUFA intake is associated with lower all-cause and cardiovascular mortality among COPD patients, suggesting that increasing dietary PUFA, particularly from plant sources, may help reduce COPD-related mortality risk.