Table 1.
Baseline Characteristics of the Study Cohort (NHANES 1999–2012)
| Characteristic | Training Set (n=8043) | Testing Set (n=7985) |
|---|---|---|
| No. (%) death of all causes | 1211 (15.1) | 1207 (15.1) |
| No. (%) death of CVD | 261 (3.2) | 256 (3.2) |
| Follow‐up, median (range), y | 7.1 (0.1–16.8) | 7.2 (0.2–16.7) |
| Age, mean (SD), y | 59.4 (12.9) | 59.3 (12.8) |
| No. (%) female | 4169 (51.8) | 4239 (53.1) |
| No. (%) racial/ethnical groups | ||
| White | 4072 (50.6) | 3990 (50.0) |
| Black | 1600 (19.9) | 1631 (20.4) |
| Hispanica | 1910 (23.8) | 1904 (23.8) |
| Other race | 462 (5.7) | 461 (5.8) |
| No. (%) current smoker | 1519 (18.9) | 1580 (19.8) |
| SBP, mean (SD), mm Hg | 129 (20) | 129 (20) |
| Total cholesterol, mean (SD), mg/dL | 202.14 (42.32) | 201.52 (42.62) |
| HDL cholesterol, mean (SD), mg/dL | 53.71 (16.56) | 53.61 (16.14) |
| No. (%) diabetes mellitus | 1540 (19.1) | 1641 (20.6) |
| BMIb, mean (SD), kg/m2 | 29.2 (6.5) | 29.2 (6.4) |
| Blood lead, median (IQR), μg/dL | 1.62 (1.10–2.49) | 1.62 (1.10–2.44) |
| Blood cadmium, median (IQR), μg/L | 0.40 (0.26–0.66) | 0.40 (0.26–0.67) |
| Total blood mercury, median (IQR), μg/L | 1.00 (0.52–1.93) | 0.97 (0.50–1.92) |
SI conversion factor: To convert values for blood lead concentrations to μmol/L, multiply by 0.0483; to convert values for blood cadmium concentrations to nmol/L, multiply by 8.897; to convert values for blood mercury concentrations to nmol/L, multiply by 4.99. BMI indicates body mass index; CVD, cardiovascular disease; HDL, high‐density lipoprotein; IQR, interquartile range; NHANES, National Health and Nutrition Examination Survey; SBP, systolic blood pressure; SI, system of units.
a
Combined from Mexican American and other Hispanic in NHANES.
b
Calculated as weight in kilograms divided by the square of height in meters.