TABLE 3.
Summary Statistics for: Demographics and Exposure Metrics (I); Blood Metals (II); and MRI Measures—R1 Regional Values and PI (III) in the 3 Post Hoc Subgroups
| A: Controls (N = 30) | B: Welders-Low (N = 17) | C: Welders-High (N = 18) | Significant Comparisons | |
|---|---|---|---|---|
| Mean ± SD (Median) | Mean ± SD (Median) | Mean ± SD (Median) | ||
| I. Demographics and exposure metrics | ||||
| Age (years) | 43.6 ± 11.5 (42.5) | 46.4 ± 11.5 (51) | 45.6 ± 11.2 (51) | |
| Education (years) | 16.2 ± 2.4 (16) | 12.9 ± 1.96 (13) | 12.7 ± 1.3 (12) | A > B*; A > C* |
| HrsW (h) | 0 ± 0 (0) | 152 ± 45 (150) | 457 ± 97 (480) | A < B < C* |
| YrsW (years) | 0 ± 0 (0) | 25.2 ± 12.1 (29) | 25.4 ± 10.7 (29.3) | A < B; A < C* |
| E90 (mg/m3—days) | 0.0027 ± 0 (0.0027) | 2.21 ± 1.17 (2.14) | 3.77 ± 1.86 (3.2) | A < B*; A < C* |
| ELT (mg/m3—years) | 0.0013 ± 0.0003 (0.0013) | 1.18 ± 0.77 (1.01) | 1.29 ± 0.78 (1.19) | A < B*; A < C* |
| AST (IU/l) | 35.7 ± 9.4 (35) | 33.5 ± 4.5 (36) | 39.4 ± 10.6 (38) | |
| ALT (IU/l) | 38.1 ± 16.9 (31) | 39.2 ± 10.2 (40) | 40.2 ± 23.7 (34.5) | |
| BMI | 25.3 ± 5.3 (26.5) | 30.2 ± 7.1 (27.8) | 27.2 ± 2.6 (27.2) | |
| Hemoglobin | 14.8 ± 0.8 (14.9) | 15.4 ± 0.8 (15.6) | 15.4 ± 1.1 (15.5) | |
| UPDRS-III | 1.5 ± 2.1 (1) | 2.1 ± 3.1 (1) | 1.9 ± 2.1 (1) | |
| II. Blood metals | ||||
| Mn (ng/ml) | 8.53 ± 2.11 (8.55) | 9.78 ± 2.5 (8.87) | 11.46 ± 3.3 (10.1) | A < C* |
| Fe (μg/ml) | 496 ± 76 (510) | 536 ± 53 (543) | 578 ± 573 (588) | A < C* |
| Cu (ng/ml) | 755 ± 137 (768) | 859 ± 116 (872) | 901 ± 136 (917) | A < C* |
| Pb (ng/ml) | 9.74 ± 8.64 (8.95) | 17.39 ± 7.59 (13.3) | 26.27 ± 25.96 (18) | A < B*; A < C* |
| K (μg/ml) | 1784 ± 351 (1675) | 1929 ± 397 (1930) | 2263 ± 336 (2352) | A < C*; B < C* |
| Cr (ng/ml) | 8.43 ± 20.8 (1.06) | 4.82 ± 5.08 (1.62) | 8.39 ± 4.94 (9.67) | A < C* |
| III. MRI measures | ||||
| GP R1 | 0.87 ± 0.06 (0.87) | 0.85 ± 0.05 (0.84) | 0.90 ± 0.05 (0.89) | B < C* |
| PUT R1 | 0.70 ± 0.05 (0.69) | 0.68 ± 0.06 (0.68) | 0.73 ± 0.04 (0.72) | A < C; B < C* |
| CN R1 | 0.66 ± 0.05 (0.66) | 0.66 ± 0.11 (0.64) | 0.68 ± 0.03 (0.67) | B < C |
| AMY R1 | 0.54 ± 0.04 (0.54) | 0.54 ± 0.09 (0.53) | 0.55 ± 0.02 (0.54) | |
| HIP R1 | 0.51 ± 0.04 (0.51) | 0.51 ± 0.06 (0.51) | 0.52 ± 0.02 (0.52) | |
| OFGM R1 | 0.65 ± 0.04 (0.64) | 0.63 ± 0.04 (0.62) | 0.65 ± 0.03 (0.65) | |
| OFWM R1 | 0.93 ± 0.08 (0.93) | 0.89 ± 0.08 (0.88) | 0.94 ± 0.04 (0.95) | B < C* |
| PI | 109 ± 2 (109) | 109 ± 2 (109) | 110 ± 3 (110) | |
Significant comparisons indicate pairwise comparisons at P < 0.05 and *comparisons that remain significant at P < 0.05 after correction for multiple group comparisons using the stepdown Bonferroni method.