Table 1.
Blood Pb, tibia bone Pb, and plasma homocysteine concentrations, by key baseline participant characteristics among study participants with data on blood Pb and homocysteine concentrations (n = 1,056).
| Characteristic | n (%) or mean ± SD | Blood Pb (μg/dL) | Tibia bone Pb (μg/g) | Plasma homocysteine (μmol/L) | |||
|---|---|---|---|---|---|---|---|
| Mean ± SD | p-Valuea | Mean ± SD | p-Valuea | GM (GSD) | p-Valuea | ||
| Overall value | 4.9 ± 2.7 | 21.4 ± 13.5 | 10.1 (1.3) | ||||
| Age (years) | 69 ± 7.4 | ||||||
| 50–65 | 355 (34) | 4.6 ± 2.6 | 0.03 | 16.5 ± 9.3 | < 0.0001 | 9.8 (1.4) | < 0.0001 |
| 66–71 | 327 (31) | 4.9 ± 2.8 | 21.8 ± 12.3 | 9.9 (1.3) | |||
| 72–97 | 374 (35) | 5 ± 2.8 | 26 ± 16.3 | 10.7 (1.3) | |||
| Education | |||||||
| < High school | 80 (8) | 5.8 ± 3 | < 0.0001 | 30.2 ± 18.6 | < 0.0001 | 9.8 (1.3) | 0.9 |
| High school | 303 (29) | 5.2 ± 2.9 | 24.7 ± 15.9 | 10.2 (1.4) | |||
| Some college | 288 (27) | 4.8 ± 2.7 | 20.3 ± 11 | 10.1 (1.3) | |||
| College degree | 202 (19) | 4.5 ± 2.3 | 18.9 ± 11.3 | 9.9 (1.3) | |||
| > College degree | 183 (17) | 4.4 ± 2.8 | 17 ± 9.4 | 10.2 (1.3) | |||
| Smoking status | |||||||
| Never | 296 (28) | 4.8 ± 3 | 0.1 | 20 ± 13.7 | 0.002 | 9.8 (1.3) | 0.005 |
| Former | 698 (66) | 4.8 ± 2.6 | 22 ± 13.6 | 10.1 (1.3) | |||
| Current | 62 (6) | 5.8 ± 3.2 | 22.1 ± 11.5 | 11.2 (1.3) | |||
| Alcohol consumption (drinks/day) | |||||||
| < 2 | 834 (79) | 4.6 ± 2.7 | < 0.0001 | 21.4 ± 13.9 | 0.5 | 9.9 (1.3) | < 0.0001 |
| ≥ 2 | 222 (21) | 5.7 ± 2.9 | 21.2 ± 12.1 | 10.8 (1.4) | |||
| BMI (kg/m2) | 28 ± 3.9 | ||||||
| < 25 | 216 (21) | 4.9 ± 2.8 | 0.5 | 21.4 ± 11.5 | 0.3 | 10.1 (1.3) | 0.9 |
| 25 to < 30 | 574 (54) | 4.8 ± 2.7 | 21.8 ± 14.3 | 10.1 (1.3) | |||
| ≥ 30 | 266 (25) | 4.8 ± 2.8 | 20.4 ± 13.3 | 10.1 (1.3) | |||
| Plasma vitamin B6 (nmol/L) | 87.5 ± 87.2 | ||||||
| < 61.8 | 561 (53.1) | 5.2 ± 2.9 | < 0.0001 | 23.0 ± 14.2 | < 0.0001 | 10.8 (1.3) | < 0.0001 |
| ≥ 61.8 | 483 (45.7) | 4.4 ± 2.5 | 19.3 ± 12.4 | 9.4 (1.3) | |||
| Plasma vitamin B12 (pg/mL) | 466.4 ± 222 | ||||||
| < 431 | 566 (53.6) | 5.1 ± 2.8 | < 0.0001 | 21.5 ± 12.0 | 0.5 | 10.8 (1.3) | < 0.0001 |
| ≥ 431 | 469 (44.4) | 4.5 ± 2.6 | 21.1 ± 14.9 | 9.3 (1.3) | |||
| Plasma folate (ng/mL) | 11 ± 7 | ||||||
| < 9.8 | 621 (58.8) | 5.2 ± 2.8 | < 0.0001 | 21.5 ± 12.9 | 0.1 | 10.7 (1.3) | < 0.0001 |
| ≥ 9.8 | 405 (38.4) | 4.4 ± 2.6 | 20.9 ± 13.8 | 9.3 (1.3) | |||
| Dietary vitamin B6 (mg/day) | 2.3 ± 0.9 | ||||||
| < 1.8 | 254 (24) | 5.4 ± 2.8 | < 0.0001 | 22.8 ± 14.7 | 0.2 | 10.6 (1.3) | 0.0002 |
| 1.8 to < 2.2 | 255 (24) | 4.9 ± 2.8 | 21 ± 12.4 | 10.1 (1.3) | |||
| 2.2 to < 2.8 | 246 (23) | 4.7 ± 2.7 | 21 ± 13.5 | 10.2 (1.3) | |||
| ≥ 2.8 | 252 (24) | 4.4 ± 2.6 | 21 ± 13.9 | 9.6 (1.3) | |||
| Dietary vitamin B12 (μg/day) | 7.9 ± 5.5 | ||||||
| < 4.4 | 252 (24) | 5 ± 2.6 | 0.9 | 22.1 ± 13.8 | 0.4 | 10.4 (1.3) | 0.2 |
| 4.4 to 6.2 | 253 (24) | 4.7 ± 2.8 | 20.1 ± 12.8 | 10.1 (1.3) | |||
| 6.2 to 9.0 | 250 (24) | 4.8 ± 2.8 | 20 ± 12.6 | 9.8 (1.3) | |||
| ≥ 9.0 | 252 (24) | 5 ± 2.8 | 23.4 ± 14.9 | 10.2 (1.3) | |||
| Dietary folate (μg/day)b | 374.8 ± 178.1 | ||||||
| < 248.5 | 135 (18) | 4.5 ± 2.8 | 0.001 | 21.7 ± 11.7 | 0.2 | 9.9 (1.3) | 0.7 |
| 248.5 to 327.3 | 134 (18) | 4.0 ± 2.4 | 21.1 ± 13.1 | 10.3 (1.3) | |||
| 327.3 to 440 | 134 (18) | 4.0 ± 2.1 | 19.3 ± 19.3 | 10.1 (1.4) | |||
| ≥ 440 | 134 (18) | 3.6 ± 1.7 | 19.6 ± 19.6 | 9.9 (1.3) | |||
| aCalculated using a test for linear trend across ordinal categories of nonmissing data. bCalculated at visit 2, due to missing data at visit 1. | |||||||