Plasma vitamin C and risk of hospitalisation with diagnosis of atrial fibrillation in men and women in EPIC-Norfolk prospective study

BackgroundFruit and vegetable intake has been associated with lower risk for cardiovascular risk factors and disease. Data on its association with atrial fibrillation are lacking.Methods and resultsWe examined the prospective association of plasma vitamin C concentration as a biomarker for fruit and vegetable intake with the risk of hospitalisation with diagnosis of atrial fibrillation in apparently healthy 8,760 men and 10,530 women aged 39-79 participating in the EPIC-study in Norfolk.The hazard ratios of atrial fibrillation comparing each quartile of plasma vitamin C concentration with the lowest were 0.76 (95% CI 0.57-1.00), 0.73 (95% CI 0.55-0.98) and 0.77 (95% CI 0.58-1.01) in women (p for trend 0.05) and 0.81 (95% CI 0.63-1.03), 0.96 (95% CI 0.76-1.22) and 1.01 (95% CI 0.79-1.28) in men (p for trend 0.66) after adjustment for age, smoking, alcohol consumption, physical activity, systolic blood pressure, diabetes, use of blood pressure medication and body-mass index, with a significant gender × vitamin C interaction (p = 0.03). Assuming a linear association, a 20 μmol/l increase in plasma vitamin C concentration (1 standard deviation) was associated with a 13% (95% CI 3-22%) relative reduction in risk of atrial fibrillation in women.ConclusionPlasma vitamin C was inversely associated with the risk of atrial fibrillation in women, but there was no such association in men. Our findings suggest that intake of food rich in vitamin C might be preventive for atrial fibrillation with a significant benefit particularly in women with low baseline intake.