Table 2.
Mean patella and tibia bone lead concentrations by key characteristics of participants with Parkinson’s disease in the study of lead exposure and cognition.
| Characteristic | Patella bone lead
|
Tibia bone lead
|
||||
|---|---|---|---|---|---|---|
| N (%)a | Mean concentration (sd), μg/g bone | P value | N (%)a | Mean concentration (sd), μg/g bone | P value | |
| Age at cognitive interview | 0.01 | 0.5 | ||||
| 54.0–64.9 | 20 (20%) | 6.3 (11.5) | 20 (20%) | 5.1 (11.5) | ||
| 65.0–69.9 | 35 (36%) | 11.1 (7.1) | 35 (35%) | 9.3 (10.9) | ||
| 70.0–74.9 | 24 (24%) | 6.6 (10.3) | 25 (25%) | 7.1 (8.4) | ||
| 75.0–80.9 | 19 (19%) | 14.7 (10.2) | 21 (21%) | 8.8 (11.8) | ||
| Sex | 0.2 | 0.9 | ||||
| Female | 44 (45%) | 8.4 (10.2) | 45 (45%) | 8.0 (10.5) | ||
| Male | 54 (55%) | 10.8 (9.7) | 56 (55%) | 7.7 (10.8) | ||
| Race | 0.7 | >0.9 | ||||
| White | 88 (87%) | 9.4 (10.1) | 88 (87%) | 7.9 (10.9) | ||
| Other | 5 (5%) | 9.4 (5.1) | 5 (5%) | 7.8 (9.4) | ||
| Missing | 8 (8%) | 12.7 (10.2) | 8 (8%) | 6.7 (8.5) | ||
| Educational attainment | 0.2 | 0.04 | ||||
| Up through high school | 19 (19%) | 11.6 (10.3) | 19 (19%) | 9.9 (9.1) | ||
| Associate’s degree | 12 (12%) | 10.2 (10.7) | 12 (12%) | 10.9 (11.5) | ||
| Bachelor’s degree | 28 (29%) | 11.8 (8.8) | 29 (29%) | 10.4 (12.5) | ||
| Master’s or doctoral degree | 39 (40%) | 7.1 (10.0) | 41 (41%) | 4.2 (8.7) | ||
| Smoking history | 0.004 | 0.07 | ||||
| Never smoked | 58 (59%) | 6.8 (9.0) | 59 (58%) | 6.2 (10.8) | ||
| Ever smoked | 40 (40%) | 13.8 (9.7) | 42 (42%) | 10.1 (10.1) | ||
| By doseb | 0.001 | 0.2 | ||||
| < 20 pack-years | 30 (75%) | 12.7 (9.5) | 32 (76%) | 9.7 (10.4) | ||
| 20+ pack-years | 10 (25%) | 17.3 (10.1) | 10 (24%) | 11.3 (9.3) | ||
| Age of PD symptom onset | 0.3 | 0.7 | ||||
| 35.0–54.9 | 12 (19%) | 7.5 (13.3) | 12 (18%) | 9.4 (12.0) | ||
| 55.0–64.9 | 30 (48%) | 7.9 (8.4) | 31 (47%) | 6.5 (11.1) | ||
| 65.0–78.9 | 21 (33%) | 12.1 (10.7) | 23 (35%) | 7.6 (10.7) | ||
a
Percentages are of the number of participants with valid data on the bone lead measure and characteristic.
b
Percentages shown are among ever smokers.