Table 2.
Baseline of included studies.
| Author | References | Publication year | Study type | Cases | Controls | Source of controls | Risk factor |
|---|---|---|---|---|---|---|---|
| Kamalesh2012 | Das et al. (2012) | 2012 | Case-control | 110 | 240 | Non-neurodegenerative disorders people | ④, ⑥, ⑦, ⑪, ⑭, ⑲, ㉘ |
| Tracy2012 | Peters et al. (2013) | 2012 | Cohort | 3,888 | 19,632 | Dweller | ① |
| Elinor2013 | Fondell et al. (2013) | 2013 | Cohort | 42 | 40,046 | Dweller | ㉒ |
| Yu2014 | Yu et al. (2014) | 2014 | Case-control | 66 | 66 | Non-neurodegenerative disorders patients | ⑤, ⑥, ⑨, ㉘ |
| Meinie2014 | Seelen et al. (2014) | 2014 | Case-control | 722 | 2,268 | Dweller | ①, ②, ③ |
| Feng2015 | Lin et al. (2015) | 2015 | Case-control | 729 | 14,580 | Dweller | ⑫ |
| Ching2015 | Tsai et al. (2015) | 2015 | Case-control | 729 | 7,290 | Dweller | ⑯, ㉓ |
| D.Mariosa2015 | Mariosa et al. (2015) | 2015 | Case-control | 224 | 1,437 | Non-ALS patients | ③ |
| Marianthi2015 | Kioumourtzoglou et al. (2016) | 2015 | Case-control | 516 | 47,787 | Dweller | ② |
| Marianthi2015 | Kioumourtzoglou et al. (2015) | 2015 | Case-control | 55 | 9,239 | Dweller | ③ |
| Mark2015 | Huisman et al. (2015) | 2015 | Case-control | 674 | 2,093 | dweller | ㉖ |
| Angela2015 | Malek et al. (2015) | 2015 | Case-control | 66 | 66 | Non-ALS patients | ⑪ |
| Yu2015 | Sun et al. (2015) | 2015 | Cohort | 615,492 | 614,835 | Non-DM patients | ③ |
| Ryan2016 | Seals et al. (2016b) | 2016 | Case-control | 116 | 8,922 | Dweller | ⑧ |
| Su2016 | Su et al. (2016) | 2016 | Case-control | 156 | 128 | Healthy control | ⑧, ⑨, ⑩, ⑬, ⑰ |
| Peters2016 | Peters et al. (2016) | 2016 | Case-control | 163 | 229 | Dweller | ㉔ |
| Harwood2016 | Harwood et al. (2016) | 2016 | Case-control | 317 | 715 | Dweller | ⑥ |
| Tracy2016 | Peters et al. (2017) | 2016 | Case-control | 59 | 227 | Dweller | ④ |
| Yvonne2016 | Eaglehouse et al. (2016) | 2016 | Cohort | 28 | 121 | Non-DM patients | ⑥ |
| Ryan2016 | Seals et al. (2016b) | 2016 | Case-control | 3,650 | 365,000 | Dweller | ① |
| Anne2018 | Visser et al. (2018) | 2018 | Case-control | 1,557 | 2,922 | Dweller | ⑥ |
| D'Ovidio2018 | D'Ovidio et al. (2018) | 2018 | Cohort | 76,279 | 651,698 | Non-DM patients | ③ |
| Ola2019 | Nakken et al. (2019) | 2019 | Cohort | 2,968 | 1,465,282 | Dweller | ㉑ |
| Tommaso2020 | Filippini et al. (2020) | 2020 | Case-control | 95 | 135 | Dweller | ④, ⑦, ⑩ |
| Andrew2021 | (Andrew A. S. et al., 2021) | 2021 | Case-control | 188 | 376 | Dweller | ①, ⑦, ⑩ |
| Andrew2021 | (Andrew A. S. et al., 2021) | 2021 | Case-control | 500 | 1,949 | Healthy control | ⑨ |
| Yu2021 | Yu et al. (2021) | 2021 | Case-control | 1,636 | 4,024 | Healthy control | ⑮ |
| Rosenbohm2021 | Rosenbohm et al. (2021) | 2021 | Case-control | 393 | 791 | Dweller | ④ |
| Skajaa2021 | Skajaa et al. (2021) | 2021 | Cohort | 852 | 974,304 | Dweller | ⑳ |
| Thompson2021 | Thompson et al. (2022) | 2021 | Cohort | 294 | 429,710 | Dweller | ㉗ |
| Sun2021 | Sun et al. (2021) | 2021 | Cohort | 483,442 | 2,392,647 | Healthy control | ㉕ |
| Beaudin2022 | Beaudin et al. (2022) | 2022 | Case-control | 403 | 378 | Healthy control | ①, ⑨ |
| Mitsumoto2022 | Mitsumoto et al. (2022) | 2022 | Case-control | 95 | 106 | Healthy control | ⑨, ⑩ |
| Andrew2022 | Andrew et al. (2022) | 2022 | Case-control | 553 | 762 | Healthy control | ⑩ |
| He2022 | He et al. (2022) | 2022 | Cohort | 140 | 203 | Healthy control | ⑱, ㉙ |
| TE2022 | Wang et al. (2023) | 2022 | Cohort | 36 | 99 | Not exposed to lead | ⑱ |
① head trauma; ② CVD, cerebrovascular disease; ③ DM, diabetes mellitus; ④ occupation; ⑤ smoking; ⑥ physical activity; ⑦ electricity shock; ⑧ military service; ⑨ pesticide; ⑩ lead; ⑪ chemical agent; ⑫ hypotensor; ⑬ educational status; ⑭ residential; ⑮ air pollution; ⑯ steroid; ⑰ service industry; ⑱ high metabolism; ⑲ water resources; ⑳ statin; ㉑ BMI, body mass index; ㉒ alopecia; ㉓ aspirin; ㉔ trace metals in blood; ㉕ intestinal biopsy; ㉖ nutrition; ㉗ lipid metabolism; ㉘ heavy metal; ㉙ FVC, forced vital capacity.