Associations of Dietary Omega-3 and Omega-6 Fatty Acids, Obesity, and Psychological Stress with Fatigue in Patients with Chronic Obstructive Pulmonary Disease: A Cross-Sectional Study

<b>Background/Aim</b>: Fatigue is a common symptom in individuals with chronic obstructive pulmonary disease (COPD) and is associated with reduced quality of life. The aim of this study was to evaluate the relationships between dietary omega-3 (<i>n</i>-3) and omega-6 (<i>n</i>-6) fatty acid intake, obesity, and stress with fatigue in patients with COPD. <b>Materials and Methods</b>: This descriptive cross-sectional study was conducted between 1 February and 31 July 2025, in the pulmonary outpatient clinics of Ağrı Training and Research Hospital in Ağrı and Atatürk University Research Hospital in Erzurum, Türkiye. Study data were collected using a General Information Questionnaire, the COPD and Asthma Fatigue Scale (CAFS), the Perceived Stress Scale (PSS), and an Adult Semi-Quantitative Food Frequency Questionnaire. Higher CAFS scores indicate greater fatigue severity, while higher PSS scores reflect higher perceived stress. <b>Results</b>: CAFS scores correlated strongly with perceived stress (r = 0.718, <i>p</i> < 0.001) and moderately with COPD exacerbation frequency (r = 0.426, <i>p</i> < 0.001). Although higher <i>n</i>-3 intake was inversely associated with fatigue in univariate analyses, this association weakened after adjustment, suggesting that fatty acid composition was not an independent determinant of fatigue. The <i>n</i>-6/<i>n</i>-3 ratio showed a weak positive correlation with fatigue (r = 0.184, <i>p</i> = 0.024). Female reported higher fatigue levels than male (mean [SD], 60.2 [19.3] vs. 51.9 [19.8]; <i>p</i> = 0.042), and patients with comorbid conditions had higher fatigue scores than those without comorbidities (58.1 [18.3] vs. 46.8 [19.4]; <i>p</i> = 0.001). Smoking status was not significantly associated with fatigue (<i>p</i> = 0.788). In backward multiple linear regression analysis, perceived stress emerged as the strongest independent predictor of fatigue (β = 0.519, <i>p</i> < 0.001). Comorbidity presence (β = 0.206, <i>p</i> = 0.030) and smoking status (β = 0.178, <i>p</i> = 0.026) were also significant, while exacerbation frequency (<i>p</i> = 0.062) and female (<i>p</i> = 0.053) showed borderline associations. <b>Conclusions</b>: These findings indicate that fatigue in COPD is primarily influenced by psychosocial stress and multimorbidity, highlighting the importance of integrative management approaches that address mental health burden and comorbid conditions alongside respiratory treatment.