Hazard ratios (95% confidence interval) of atrial fibrillation by categories of DHA+EPA intake, ARIC, 1987–2008.

<p>Dietary DHA and EPA adjusted for energy using the residual method. CI: Confidence interval. HR: Hazard ratio. Model 1: adjusted for age, sex, and race; Model 2: adjusted for center, age, race, sex, energy intake, BMI, education, exercise levels, smoking status and amount, alcohol intake, HDL-C, LDL-C, use of cholesterol lowering medications, systolic blood pressure, use of antihypertensive medications, diabetes, coronary heart disease, and ECG-defined left ventricular hypertrophy.</p

Hazard ratio (95% confidence interval) of atrial fibrillation by combined dietary and biomarker DHA and EPA, ARIC Minnesota field center, 1987–2005.

*<p>Adjusted for age, sex, BMI, education, energy intake, exercise levels, smoking status and amount, alcohol intake, total cholesterol, use of cholesterol lowering medications, systolic blood pressure, use of antihypertensive medications, diabetes, coronary heart disease, and ECG-defined left ventricular hypertrophy.</p><p>CI: Confidence interval. HR: hazard ratio.</p

Baseline characteristics of ARIC participants (n = 14,222), 1987–1989.

<p>Values are % for categorical variables and mean (SD) for continuous variables. BMI: Body mass index. CHD: Coronary heart disease. DHA: Docosahexaenoic acid. ECG: Electrocardiogram. EPA: Eicosapentanoic acid.</p

Hazard ratios (95% confidence intervals) of atrial fibrillation by fish intake categories, ARIC, 1987–2008.

<p>CI: Confidence interval. HR: Hazard ratio. Model 1: adjusted for age, sex, and race; Model 2: adjusted for center, age, race, sex, energy intake, body mass index, education, exercise levels, smoking status and amount, alcohol intake, LDL cholesterol, HDL cholesterol, use of cholesterol lowering medications, systolic blood pressure, use of antihypertensive medications, diabetes, coronary heart disease, and ECG-defined left ventricular hypertrophy.</p

Association of White Blood Cell Count and Differential with the Incidence of Atrial Fibrillation: The Atherosclerosis Risk in Communities (ARIC) Study

<div><p>Background</p><p>Although inflammation is involved in the development of atrial fibrillation (AF), the association of white blood cell (WBC) count and differential with AF has not been thoroughly examined in large cohorts with extended follow-up.</p><p>Methods</p><p>We studied 14,500 men and women (25% blacks, 55% women, mean age 54) free of AF at baseline (1987–89) from the Atherosclerosis Risk in Communities (ARIC) study, a community-based cohort in the United States. Incident AF cases through 2010 were identified from study electrocardiograms, hospital discharge records and death certificates. Multivariable Cox proportional hazards regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for AF associated with WBC count and differential.</p><p>Results</p><p>Over a median follow-up time of 21.5 years for the entire cohort, 1928 participants had incident AF. Higher total WBC count was associated with higher AF risk independent of AF risk factors and potential confounders (HR 1.09, 95% CI 1.04–1.15 per 1-standard deviation [SD] increase). Higher neutrophil and monocyte counts were positively associated with AF risk, while an inverse association was identified between lymphocyte count and AF (multivariable adjusted HRs 1.16, 95% CI 1.09–1.23; 1.05, 95% CI 1.00–1.11; 0.91, 95% CI 0.86–0.97 per 1-SD, respectively). No significant association was identified between eosinophils or basophils and AF.</p><p>Conclusions</p><p>High total WBC, neutrophil, and monocyte counts were each associated with higher AF risk while lymphocyte count was inversely associated with AF risk. Systemic inflammation may underlie this association and requires further investigation for strategies to prevent AF.</p></div

Association between each white blood cell differential count and incident atrial fibrillation presented as hazard ratio (solid line) and 95% confidence intervals (shaded area), Atherosclerosis Risk in Communities Study, 1987 to 2010.

<p>(A) Neutrophil Count; (B) Lymphocyte Count; (C) Neutrophil Count/Lymphocyte Count Ratio; (D) Monocyte Count; (E) Eosinophil Count. *Cox proportional hazards model using restricted cubic splines with knots at the 5^th, 27.5^th, 50^th, 72.5^th and 95^th percentiles and adjustment for age, race, and sex. The reference is the median value of each white blood cell differential count (hazard ratio = 1), and the histogram represents the frequency distribution of each white blood cell differential count in the study sample.</p

Baseline characteristics by total white blood cell (WBC) count quintile, Atherosclerosis Risk in Communities Study, 1987 to 1989.

<p>BP indicates blood pressure. Values are mean (SD) when appropriate.</p><p>*Reduced sample size: n = 10,661</p><p>†All baseline characteristics have p-values <0.05 for differences in means (ANOVA) and percentages (Chi-Square) between total WBC quintiles except for height and prevalent stroke.</p><p>Baseline characteristics by total white blood cell (WBC) count quintile, Atherosclerosis Risk in Communities Study, 1987 to 1989.</p

Hazard ratio (HR) and 95% confidence interval (CI) of atrial fibrillation (AF) by white blood cell differential count, Atherosclerosis Risk in Communities Study, 1987 to 2010.

<p><b>Model 1:</b> Cox proportional hazards model adjusted for age, race, sex, and study site.</p><p><b>Model 2:</b> Model 1 with additional adjustment for body mass index, chronic obstructive pulmonary disease, diabetes mellitus, drinking status, educational level, height, pack-years, smoking status, systolic blood pressure, use of antihypertensive medications, and prevalent heart failure, myocardial infarction, or stroke at baseline.</p><p><b>Model 3:</b> Model 2 with additional adjustment for heart failure, myocardial infarction, or stroke as time-varying covariates.</p><p><b>*Neutrophil Count SD = 1.42 x 10</b>^<b>9</b><b>/L, Lymphocyte Count SD = 0.64 x 10</b>^<b>9</b><b>/L, Neutrophil/Lymphocyte Ratio SD = 1.25; Monocyte Count SD = 0.18 x 10</b>^<b>9</b><b>/L, Eosinophil Count SD = 0.15 x 10</b>^<b>9</b><b>/L, Basophil Count SD = 0.04 x 10</b>^<b>9</b><b>/L</b></p><p>Hazard ratio (HR) and 95% confidence interval (CI) of atrial fibrillation (AF) by white blood cell differential count, Atherosclerosis Risk in Communities Study, 1987 to 2010.</p

Hazard ratio (HR) and 95% confidence interval (CI) of atrial fibrillation (AF) by total white blood cell (WBC) count, Atherosclerosis Risk in Communities Study, 1987 to 2010.

<p><b>Model 1:</b> Cox proportional hazards model adjusted for age, race, sex, and study site.</p><p><b>Model 2:</b> Model 1 with additional adjustment for body mass index, chronic obstructive pulmonary disease, diabetes mellitus, drinking status, educational level, height, pack-years, smoking status, systolic blood pressure, use of antihypertensive medications, and prevalent heart failure, myocardial infarction, or stroke at baseline.</p><p><b>Model 3:</b> Model 2 with additional adjustment for heart failure, myocardial infarction, or stroke as time-varying covariates.</p><p><b>*Total WBC Count SD = 1.70 x 10</b>^<b>9</b><b>/L</b></p><p>Hazard ratio (HR) and 95% confidence interval (CI) of atrial fibrillation (AF) by total white blood cell (WBC) count, Atherosclerosis Risk in Communities Study, 1987 to 2010.</p

Flow chart of participants excluded at baseline, Atherosclerosis Risk in Communities Study, 1987 to 1989.

<p>ECG = electrocardiogram. WBC = White Blood Cell.</p