Table 1.
Baseline Characteristics
| Characteristics | Incident Atrial Fibrillation |
p Value | |||
|---|---|---|---|---|---|
| Yes (n = 1,580) | No (n = 10,135) | ||||
| Mean* | SD | Mean* | SD | ||
| Age, yrs | 56.5 | 5.4 | 53.7 | 5.7 | <0.001 |
| Male | 0.53 | 0.42 | <0.001 | ||
| White | 0.82 | 0.74 | <0.001 | ||
| Education | <0.001 | ||||
| Less than high school | 0.28 | 0.22 | |||
| High school but less than college | 0.41 | 0.42 | |||
| College or professional | 0.31 | 0.36 | |||
| Hypertension | 0.45 | 0.32 | <0.001 | ||
| Diabetes | 0.16 | 0.10 | <0.001 | ||
| Prevalent CHD | 0.09 | 0.04 | <0.001 | ||
| Prevalent heart failure | 0.08 | 0.04 | <0.001 | ||
| Current smoker | 0.30 | 0.25 | <0.001 | ||
| Former smoker | 0.35 | 0.32 | <0.001 | ||
| Cigarette-years of smoking | 408.2 | 496.3 | 291.1 | 415.7 | <0.001 |
| Usual ethanol intake, g/week | 44.63 | 97.1 | 40.54 | 92.0 | 0.10 |
| LDL cholesterol, mg/dl | 139.0 | 39.1 | 137.0 | 39.1 | 0.05 |
| HDL cholesterol, mg/dl | 48.6 | 15.7 | 52.7 | 17.3 | <0.001 |
| BMI, kg/m2 | 28.7 | 5.6 | 27.4 | 5.2 | <0.001 |
| Cornell voltage, mm | 12.9 | 5.8 | 12.1 | 5.4 | <0.001 |
| Mean RR interval, ms | 916.2 | 144.2 | 904.4 | 135.3 | 0.001 |
| Log (SDNN) | 3.43 | 0.53 | 3.51 | 0.48 | <0.001 |
| Log (RMSSD) | 3.10 | 0.68 | 3.18 | 0.61 | <0.001 |
| Log (LF) | 2.40 | 1.48 | 2.71 | 1.34 | <0.001 |
| Log (HF) | 1.80 | 1.45 | 2.11 | 1.29 | <0.001 |
| Log (LF/HF) | 0.60 | 0.97 | 0.60 | 0.92 | 0.91 |
*
Mean or proportion
BMI = body mass index; CHD = coronary heart disease; HDL = high-density lipoprotein; HF = high frequency; LDL = low-density lipoprotein; LF = low frequency; RMSSD = root mean square of successive differences in normal-to-normal R-R intervals; SDNN = standard deviation of normal-to-normal R-R intervals.