Background: Atrial fibrillation (AF) is a common cardiac arrhythmia affecting over 6 million people in the U.S. Fatigue is a frequent symptom of AF, yet no underlying biological mechanisms have been identified in AF-related fatigue as in other chronic conditions such as cancer or HIV fatigue (inflammation, tissue injury). We aimed to identify biomarkers and correlates of AF-fatigue in ARIC participants.
Methods: Participants with AF from ARIC visit 5 (2011-2013) were included in the study. Multiple linear regression was used to estimate the association of high sensitivity troponin (hs-TnT), N-terminal fragment B-type natriuretic peptide (NT-proBNP) and high sensitivity C-reactive protein (hsCRP) levels with self-reported fatigue (SF-12 and PROMIS Fatigue Scale), depressive symptoms (Center for Epidemiological Studies Depression survey), and physical functioning (Short Physical Performance Battery) scores. All biomarkers underwent natural-log transformation.
Results: There were 446 participants (mean age: 78 y ± 5; 44% women). In adjusted analyses, NT-proBNP was associated with AF-fatigue (β: 0.11, 95% CI: 0.03, 0.19), increased depressive symptoms (β: 0.44, 95% CI: 0.19, 0.70), and decreased physical function (β: -0.48, 95% CI: -0.72, -0.23). Hs-TnT was also associated with elevated AF-fatigue (β: 0.24, 95% CI: 0.09, 0.39) along with decreased physical function (β: -1.19, 95% CI: -1.64, -0.75). No significant associations were found with hsCRP and fatigue.
Conclusion: Increased levels of cardiac injury biomarkers, depressive symptoms, and decreased physical function were associated with AF-fatigue. Inflammation was not associated with AF-fatigue; other physiological pathways, such as cardiac overload or myocardial injury may be more relevant in AF-fatigue.
Keywords: atrial fibrillation; biomarkers; fatigue; inflammation.