Table 2.
Group comparisons of GABA levels, individual exposure levels with three exposure windows, R1 values and UPDRS scores with rigidity and tremor scores, listed as mean (standard deviation) for each group.
| Controls | Welders | LEX Welders | HEX Welders | |
|---|---|---|---|---|
| Exposure levels ((mg/m3)·yr) | ||||
| Past-3-Month | 0.000 (0.000) | 0.037 (0.033)*** | 0.021 (0.010)*** | 0.069 (0.040)***,### |
| Past-12-Month | 0.002 (0.001) | 0.174 (0.142)*** | 0.108 (0.090)*** | 0.307 (0.135)***,### |
| Cumulative | 0.040 (0.035) | 1.886 (1.664)*** | 1.448 (1.510)*** | 2.763 (1.665)***,# |
| GABA levels (mM) | ||||
| Thalamic GABA | 1.563 (0.638) | 1.881 (0.829) | 1.624 (0.670) | 2.395 (0.900)**,## |
| Striatal GABA | 1.922 (0.606) | 1.684 (0.403) | 1.656 (0.422) | 1.743 (0.370) |
| R1 values (1/s) | ||||
| Globus Pallidus | 0.869 (0.096) | 0.986 (0.154)** | 0.955 (0.119)** | 1.049 (0.198)*** |
| Substantia Nigra | 0.800 (0.136) | 0.858 (0.124) | 0.834 (0.128) | 0.906 (0.102)* |
| Caudate Nucleus | 0.704 (0.083) | 0.764 (0.103)* | 0.754 (0.106) | 0.784 (0.096)* |
| Frontal Cortex | 0.915 (0.136) | 1.074 (0.225)** | 1.078 (0.243)** | 1.068 (0.192)** |
| UPDRS | ||||
| Total Score | 5.0 (3.2) | 7.9 (5.0)* | 6.8 (4.4) | 10.2 (5.7)** |
| Rigidity | 2.6 (1.7) | 2.1 (1.5) | 2.1 (1.7) | 2.0 (1.2) |
| Tremor | 0.6 (0.9) | 0.7 (1.0) | 0.5 (0.9) | 1.3 (0.9)*,## |
*,**,***
p<0.05, p<0.01, p<0.001 for comparison to the control group
#,##,###
p<0.05, p<0.01, p<0.001 for comparison between welders with higher exposure (HEX) and lower exposure (LEX)