Table 1.
Summary statistics [mean ± SD or n (%)] at baseline for participants with and without bone lead measurements in the NAS.
| Characteristic | With bone lead measure (n = 517) | Without bone lead measure (n = 162) | p-Valuea |
|---|---|---|---|
| Tibia lead (g/g) | 20.5 ± 14.8 | — | |
| Patella lead (g/g) | 27.4 ± 19.7b | — | |
| Blood lead (μg/dL) | 4.1 ± 2.4c | 3.9 ± 2.1d | 0.59 |
| Alu (%) | 26.3 ± 1.0 | 26.2 ± 1.2 | 0.27 |
| LINE-1 (%) | 76.8 ± 1.9 | 77.1 ± 2.1 | 0.16 |
| Age (years) | 72.4 ± 6.5 | 72.5 ± 7.6 | 0.95 |
| BMI (kg/m2) | 28.0 ± 3.8 | 28.5 ± 4.5 | 0.45 |
| Lymphocytes (%) | 25.5 ± 8.6 | 25.7 ± 7.2 | 0.56 |
| Pack-years of cigarettes | 20.1 ± 25.3 | 25.6 ± 32.7 | 0.02 |
| Education | 0.85 | ||
| Less than high school diploma | 46 (8.9) | 10 (6.2) | |
| High school diploma/some college | 314 (60.7) | 88 (54.3) | |
| Four years of college | 143 (27.7) | 39 (24.1) | |
| Missing | 14 (2.7) | 25 (15.4) |
a
p-Values for differences between subjects with and without bone lead measurements from Wilcoxon rank sum or Fisher’s exact test.
b
n = 508 for patella and 517 for tibia.
c
n = 463.
d
n = 127.