Table 1. Age and risk markers of PD in the prospective TREND study.
| Features | Visit 1 | Visit 2 | Visit 3 | Visit 4 | ||||
|---|---|---|---|---|---|---|---|---|
| Risk markers | Category | PD-free (n = 1178) | PD-free (n = 1070) | Incident PD (n = 6) | PD-free (n = 981) | Incident PD (n = 5) | PD-free (n = 880) | Incident PD (n = 5) |
| Age at visit 1 | 63 (58, 68) | 65 (60, 70) | 74 (70, 74) | 67 (62, 72) | 75 (73, 76) | 69 (64, 74) | 70 (68, 71) | |
| Sex | Male | 599 (51%) | 546 (51%) | 5 (83%) | 503 (51%) | 5 (100%) | 464 (53%) | 3 (60%) |
| Female | 579 (49%) | 524 (49%) | 1 (17%) | 478 (49%) | 0 (0%) | 416 (47%) | 2 (40%) | |
| PD family history | No | 1010 (86%) | 917 (86%) | 3 (50%) | 840 (86%) | 4 (80%) | 751 (85%) | 4 (80%) |
| Yes | 168 (14%) | 153 (14%) | 3 (50%) | 141 (14%) | 1 (20%) | 129 (15%) | 1 (20%) | |
| Polygenic risk score | Marker absent | 247 (21%) | 218 (20%) | 2 (33%) | 204 (21%) | 1 (20%) | 181 (21%) | 3 (60%) |
| Borderline | 500 (42%) | 459 (43%) | 2 (33%) | 420 (43%) | 2 (40%) | 380 (43%) | 1 (20%) | |
| Marker present | 252 (21%) | 237 (22%) | 1 (17%) | 218 (22%) | 1 (20%) | 197 (22%) | 0 (0%) | |
| Missing | 179 (15%) | 156 (15%) | 1 (17%) | 139 (14%) | 1 (20%) | 22 (14%) | 1 (20%) | |
| GBA mutation | No | 1126 (96%) | 1021 (95%) | 6 (100%) | 938 (96%) | 2 (40%) | 845 (96%) | 4 (80%) |
| Yes | 52 (4%) | 49 (5%) | 0 (0%) | 43 (4%) | 3 (60%) | 35 (4%) | 1 (20%) | |
| SN hyperechogenicity | SN- | 839 (71%) | 771 (72%) | 1(17%) | 714 (73%) | 3 (60%) | 641 (73%) | 3 (60%) |
| SN+ | 210 (18%) | 191 (18%) | 5 (83%) | 178 (18%) | 2 (40%) | 168 (19%) | 2 (40%) | |
| Missing | 129 (11%) | 108 (10%) | 0 (0%) | 89 (9%) | 0 (0%) | 71 (8%) | 0 (0%) | |
| Occupational pesticide exposure | No | 878 (75%) | 855 (80%) | 1(17%) | 839 (86%) | 1 (20%) | 813 (92%) | 3 (60%) |
| Yes | 19 (2%) | 18 (2%) | 0 (0%) | 17 (2%) | 0 (0%) | 17 (2%) | 0 (0%) | |
| Missing | 281 (24%) | 197 (18%) | 5 (83%) | 125 (13%) | 4 (80%) | 50 (6%) | 2 (40%) | |
| Occupational solvent exposure | Yes | 774 (66%) | 753 (70%) | 1 (17%) | 739 (75%) | 1 (20%) | 714 (81%) | 2 (40%) |
| No | 129 (11%) | 125 (12%) | 0 (0%) | 122 (12%) | 0 (0%) | 117 (13%) | 1 (20%) | |
| Missing | 275 (23%) | 192 (18%) | 5 (83%) | 120 (12%) | 4 (80%) | 49 (6%) | 2 (40%) | |
| Diabetes type II | No | 1131 (96%) | 1015 (95%) | 5 (83%) | 922 (94%) | 5 (100%) | 826 (94%) | 4 (80%) |
| Yes | 47 (4%) | 55 (5%) | 1 (17%) | 59 (6%) | 0 (0%) | 54 (6%) | 1 (20%) | |
| Missing | 0 (0%) | 0 (0%) | 0 (0%) | 0 (0%) | 0 (0%) | 0 (0%) | 0 (0%) | |
| Physical inactivity | No | 542 (46%) | 343 (32%) | 1 (17%) | 754 (77%) | 4 (80%) | 701 (80%) | 3 (60%) |
| Yes | 142 (12%) | 98(9%) | 0 (0%) | 223 (23%) | 1 (20%) | 176 (20%) | 2 (40%) | |
| Missing | 494 (42%) | 629 (59%) | 5 (83%) | 4 (0%) | 0 (0%) | 3 (0%) | 0 (0%) | |
| Non-smoking | Marker absent | 535 (45%) | 478 (45%) | 2 (33%) | 438 (45%) | 3(60%) | 396 (45%) | 0 (0%) |
| Borderline | 533 (45%) | 509 (48%) | 4 (67%) | 470 (48%) | 2(40%) | 422 (48%) | 4 (80%) | |
| Marker present | 109 (9%) | 83 (8%) | 0 (0%) | 72 (7%) | 0 (0%) | 61 (7%) | 1 (20%) | |
| Missing | 1 (0.1%) | 0 (0%) | 0 (0%) | 1 (0.1%) | 0 (0%) | 1 (0.1%) | 0 (0%) | |
Summary statistics of age and risk markers of PD-free individuals and incident PD cases at different visits, absolute and relative (%) frequencies of marker presence or median (inter-quartile range in brackets) are given unless specified otherwise. Sample sizes per visit are indicated. Missingness of marker data within a given visit is indicated, i.e. not considering longitudinal study dropout. Percentage values indicate the relative frequency of marker presence/absence/borderline/missingness within PD-free and incident PD groups, respectively, and within each visit. GBA, glucocerebrosidase; PD, Parkinson’s disease; SN, substantia nigra.