Low levels of plasma carotenoids are associated with an increased risk of atrial fibrillation

Systemic inflammation, oxidative stress, and atrial fibrosis are identified as the main mechanisms for atrial fibrillation (AF). Antioxidant micronutrients may have antiarrhythmic benefit in humans. We studied whether plasma carotenoids are related to the risk of AF in elderly subjects. The study population consisted of 1,847 Finnish subjects (620 women and 1,227 men) aged 61-82 years from the Kuopio Ischaemic Heart Disease Risk Factor study cohort. Plasma concentrations of carotenoids were measured by high-performance liquid chromatography. The multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of plasma carotenoids were analyzed using the Cox proportional hazard's model. During a median follow-up of 2.8 years a total of 105 subjects developed incident AF. The HRs of AF among subjects with levels in the highest through the lowest tertile after adjustment for age, examination year, gender, systolic blood pressure, smoking, alcohol consumption, education, diabetes, use of antihypertensive medication, congestive heart failure, recurrent AF, prevalent coronary heart disease and baseline prevalence of myocardial infarction were 1.70 (95% CI: 1.01-2.86, p = 0.047) for lutein, 1.99 (95% CI: 1.14-3.48, p = 0.016) for zeaxanthin. Risk of AF was borderline significant for β-carotene (HR = 1.69, 95 % CI: 1.00-2.87, p = 0.050). Results remained unchanged, when season was added to the multivariable model. Lycopene, β-cryptoxanthin, α-carotene and total carotenoids were not associated with the risk of AF. Results of the present study suggest that low plasma concentrations of lutein and zeaxanthin were associated with an increased risk of AF in elderly population.