Introduction
Methods
Participants and data collection
Study design
Statistical analysis
Results
Participants (Fig. 1; Table 1)
All subjects | Men | Women | ||||
---|---|---|---|---|---|---|
Cases | Controls | Cases | Controls | Cases | Controls | |
N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | |
Responders | 374 (37.5) | 623 (62.5) | 136 (37.3) | 229 (62.7) | 238 (37.7) | 394 (62.3) |
Age category (years) | ||||||
18–30 | 38 (10.2) | 58 (9.3) | 9 (6.6) | 13 (5.7) | 29 (12.2) | 45 (11.4) |
30–40 | 45 (12.0) | 62 (10.0) | 9 (6.6) | 12 (5.2) | 36 (15.1) | 50 (12.7) |
40–50 | 85 (22.7) | 137 (22.0) | 21 (15.4) | 32 (14.0) | 64 (26.9) | 105 (26.6) |
50–60 | 105 (28.1) | 173 (27.8) | 44 (32.4) | 70 (30.6) | 61 (25.6) | 103 (26.1) |
60–70 | 101 (27.0) | 193 (31.0) | 53 (39.0) | 102 (44.5) | 48 (20.2) | 91 (23.1) |
BMI category | ||||||
Underweight (BMI < 18.5) | 5 (1.4) | 5 (0.8) | 0 (0) | 0 (0) | 5 (2.1) | 5 (1.3) |
Normal weight (18.5 ≤ BMI < 25) | 206 (56.0) | 261 (43.0) | 63 (47.0) | 73 (32.6) | 143 (61.1) | 188 (49.1) |
Overweight (25 ≤ BMI < 30) | 102 (27.7) | 230 (37.9) | 48 (35.8) | 110 (49.1) | 54 (23.1) | 120 (31.3) |
Obese (BMI ≥ 30) | 55 (14.9) | 111 (18.3) | 23 (17.2) | 41 (18.3) | 32 (13.7) | 70 (18.3) |
Tobacco use | ||||||
Daily cigarette smoking | 33 (8.9) | 49 (7.9) | 9 (6.7) | 19 (8.3) | 24 (10.1) | 30 (7.7) |
Daily snuff use | 57 (15.4) | 66 (10.7) | 37 (27.4) | 46 (20.3) | 20 (8.5) | 20 (5.2) |
Any daily tobacco use | 89 (23.8) | 107 (17.2) | 45 (33.1) | 61 (26.6) | 44 (18.5) | 46 (11.7) |
Area of livelihood | ||||||
Alpine | 87 (23.3) | 146 (23.4) | 33 (24.3) | 60 (26.2) | 54 (22.7) | 86 (21.8) |
Inland | 110 (29.4) | 176 (28.3) | 46 (33.8) | 72 (31.4) | 64 (26.9) | 104 (26.4) |
Coastal | 177 (47.3) | 301 (48.3) | 57 (41.9) | 97 (42.4) | 120 (50.4) | 204 (51.8) |
Occupation | ||||||
Armed forces occupations | 2 (0.6) | 3 (0.5) | 1 (0.8) | 2 (0.9) | 1 (0.4) | 1 (0.3) |
Managers | 9 (2.5) | 22 (3.6) | 6 (4.5) | 7 (3.1) | 3 (1.3) | 15 (3.9) |
Professionals | 73 (20.2) | 115 (19.0) | 17 (12.9) | 24 (10.7) | 56 (24.5) | 91 (23.9) |
Technicians and associate professionals | 28 (7.8) | 70 (11.6) | 14 (10.6) | 34 (15.2) | 14 (6.1) | 36 (9.4) |
Clerical support workers | 40 (11.1) | 47 (7.8) | 10 (7.6) | 12 (5.4) | 30 (13.1) | 35 (9.2) |
Service and sales workers | 57 (15.8) | 107 (17.7) | 11 (8.3) | 30 (13.4) | 46 (20.1) | 77 (20.2) |
Skilled agricultural, forestry, and fishery workers | 6 (1.7) | 9 (1.5) | 2 (1.5) | 3 (1.3) | 4 (1.7) | 6 (1.6) |
Crafts and related trades workers | 17 (4.7) | 26 (4.3) | 14 (10.6) | 19 (8.5) | 3 (1.3) | 7 (1.8) |
Plant and machine operators and assemblers | 27 (7.5) | 27 (4.5) | 22 (16.7) | 22 (9.8) | 5 (2.2) | 5 (1.3) |
Elementary occupations | 6 (1.7) | 13 (2.1) | 3 (2.3) | 5 (2.2) | 3 (1.3) | 8 (2.1) |
Self-employed | 8 (2.2) | 13 (2.1) | 2 (1.5) | 8 (3.6) | 6 (2.6) | 9 (2.4) |
Students | 11 (3.0) | 16 (2.6) | 1 (0.8) | 0 (0) | 10 (4.4) | 16 (4.2) |
Unemployed | 4 (1.1) | 9 (1.5) | 2 (1.5) | 4 (1.8) | 2 (0.9) | 5 (1.3) |
Parental leave | 3 (0.8) | 4 (0.7) | 0 (0) | 0 (0) | 3 (1.3) | 4 (1.0) |
Sick leave | 12 (3.3) | 12 (2.0) | 1 (0.8) | 3 (1.3) | 11 (4.8) | 9 (2.4) |
Retired | 58 (16.1) | 112 (18.5) | 26 (19.7) | 51 (22.8) | 32 (14.0) | 61 (16.0) |
Study population characteristics (Table 1)
Univariate conditional logistic regression analyses (Tables 2, 3)
Factor | Exposure level | All subjects | Men | Women | ||||||
---|---|---|---|---|---|---|---|---|---|---|
Cases | Controls | OR (95% CI) | Cases | Controls | OR (95% CI) | Cases | Controls | OR (95% CI) | ||
N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | |||||
BMI category | BMI < 18.5 | 5 (1.4) | 5 (0.8) | 1.6 (0.4–6.7) | 0 (0.0) | 0 (0.0) | – | 5 (2.1) | 5 (1.3) | 1.6 (0.4–6.7) |
18.5 ≤ BMI < 25 | 206 (56.0) | 261 (43.0) | Reference | 63 (47.0) | 73 (32.6) | Reference | 143 (61.1) | 188 (49.1) | Reference | |
25 ≤ BMI < 30 | 102 (27.7) | 230 (37.9) | 0.5 (0.4–0.7)* | 48 (35.8) | 110 (49.1) | 0.5 (0.3–0.8)* | 54 (23.1) | 120 (31.3) | 0.6 (0.4–0.8)* | |
BMI ≥ 30 | 55 (14.9) | 111 (18.3) | 0.6 (0.4–9)* | 23 (17.2) | 41 (18.3) | 0.6 (0.3–1.1) | 32 (13.7) | 70 (18.3) | 0.6 (0.4–0.96)* | |
Any daily tobacco use | Yes | 89 (23.8) | 107 (17.2) | 1.5 (1.1–2.0)* | 45 (33.1) | 61 (26.6) | 1.3 (0.9–2.1) | 44 (18.5) | 46 (11.7) | 1.6 (1.04–2.6)* |
No | 285 (76.2) | 516 (82.8) | Reference | 91 (66.9) | 168 (73.4) | Reference | 194 (81.5) | 348 (88.3) | Reference | |
Therapeutic drug use | ||||||||||
Affecting peripheral nervesa | Yes | 33 (11.1) | 54 (12.3) | 1.0 (0.6–1.7) | 19 (18.3) | 31 (20.3) | 0.7 (0.4–1.6) | 14 (7.3) | 23 (8.1) | 1.3 (0.6-3.0) |
No | 263 (88.9) | 384 (87.7) | Reference | 85 (81.7) | 122 (79.7) | Reference | 178 (92.7) | 262 (91.9) | Reference | |
Affecting peripheral circulationb | Yes | 55 (19.1) | 81 (18.9) | 1.3 (0.8–2.1) | 22 (22.0) | 24 (16.4) | 1.7 (0.7–3.7) | 33 (17.6) | 57 (20.1) | 1.1 (0.6-2.0) |
No | 233 (80.9) | 348 (81.1) | Reference | 78 (78.0) | 122 (83.6) | Reference | 155 (82.4) | 226 (79.9) | Reference | |
Diseases and injuries | ||||||||||
Vascular diseasec | Yes | 109 (29.1) | 151 (25.5) | 1.8 (1.3–2.6)* | 50 (41.0) | 70 (32.4) | 2.2 (1.2–3.9)* | 59 (26.6) | 81 (21.6) | 1.6 (1.04–2.5)* |
No | 235 (68.3) | 440 (74.5) | Reference | 72 (59.0) | 146 (67.6) | Reference | 163 (73.4) | 294 (78.4) | Reference | |
Diabetes mellitus | Yes | 13 (3.5) | 28 (4.6) | 0.9 (0.5–1.8) | 6 (4.4) | 12 (5.4) | 0.9 (0.3–2.4) | 7 (3.0) | 16 (4.1) | 0.9 (0.4–2.3) |
No | 356 (96.5) | 581 (95.4) | Reference | 129 (95.6) | 211 (94.6) | Reference | 227 (97.0) | 370 (95.9) | Reference | |
Migraines | Yes | 59 (16.1) | 50 (8.2) | 2.2 (1.4–3.3)* | 12 (9.0) | 10 (4.4) | 2.0 (0.9–4.7) | 47 (20.2) | 40 (10.5) | 2.2 (1.4–3.6)* |
No | 307 (83.9) | 558 (91.8) | Reference | 121 (91.0) | 216 (95.6) | Reference | 186 (79.8) | 342 (89.5) | Reference | |
Rheumatic diseased | Yes | 66 (18.1) | 45 (7.4) | 3.2 (2.1-5.0)* | 15 (11.4) | 16 (7.1) | 2.0 (0.9–4.3) | 51 (21.9) | 29 (7.6) | 3.9 (2.3–6.8)* |
No | 299 (81.9) | 562 (92.6) | Reference | 117 (88.6) | 208 (92.9) | Reference | 182 (78.1) | 354 (92.4) | Reference | |
Carpal tunnel syndrome | Yes | 39 (10.9) | 50 (8.2) | 1.5 (0.9–2.3) | 13 (10.0) | 19 (8.5) | 1.3 (0.6-3.0) | 26 (11.4) | 31 (8.1) | 1.6 (0.9–2.7) |
No | 320 (89.1) | 559 (91.8) | Reference | 117 (90.0) | 205 (91.5) | Reference | 203 (88.6) | 354 (91.9) | Reference | |
Polyneuropathy | Yes | 13 (3.6) | 4 (0.7) | 7.4 (2.1–26.4)* | 7 (5.3) | 2 (0.9) | 10.2 (1.2–85.4)* | 6 (2.6) | 2 (0.5) | 6.0 (1.2–29.7)* |
No | 350 (96.4) | 602 (99.3) | Reference | 125 (94.7) | 222 (99.1) | Reference | 225 (97.4) | 380 (99.5) | Reference | |
Upper extremity nerve injury | Yes | 119 (32.6) | 112 (18.3) | 2.3 (1.7–3.1)* | 50 (37.6) | 47 (20.6) | 2.3 (1.4–3.7)* | 69 (29.7) | 65 (16.9) | 2.3 (1.5–3.5)* |
No | 246 (67.4) | 500 (81.7) | Reference | 83 (62.4) | 181 (79.4) | Reference | 163 (70.3) | 319 (83.1) | Reference | |
Frostbite hands | Yes | 114 (30.6) | 34 (5.5) | 10.2 (6.0–17.2)* | 53 (39.0) | 13 (5.7) | 18.9 (6.8–52.6)* | 61 (25.8) | 21 (5.4) | 7.2 (3.9–13.6)* |
No | 258 (69.4) | 583 (94.5) | Reference | 83 (61.0) | 215 (94.3) | Reference | 175 (74.2) | 368 (94.6) | Reference |
Factor | Exposure level | All subjects | Men | Women | ||||||
---|---|---|---|---|---|---|---|---|---|---|
Cases | Controls | OR (95% CI) | Cases | Controls | OR (95% CI) | Cases | Controls | OR (95% CI) | ||
N (%) | N (%) | N (%) | N (%) | N (%) | N (%) | |||||
Cold exposure measures | ||||||||||
Occupational cold exposurea (NRS 1–10) | High (NRS > 1) | 182 (50.4) | 242 (40.8) | 1.4 (1.1–1.9)* | 88 (67.7) | 132 (60.8) | 1.3 (0.8–2.1) | 94 (40.7) | 110 (29.3) | 1.5 (1.1–2.2)* |
Low (NRS 1) | 179 (49.6) | 351 (59.2) | Reference | 42 (32.3) | 85 (39.2) | Reference | 137 (59.3) | 266 (70.7) | Reference | |
Leisure-time cold exposureb (NRS 1–10) | High (NRS > 5) | 194 (52.9) | 301 (49.3) | 1.1 (0.8–1.4) | 69 (51.1) | 118 (52.0) | 1.0 (0.6–1.4) | 125 (53.9) | 183 (47.8) | 1.2 (0.9–1.7) |
Low (NRS ≤ 5) | 173 (47.1) | 309 (50.7) | Reference | 66 (48.9) | 109 (48.0) | Reference | 107 (46.1) | 200 (52.2) | Reference | |
Cumulative cold exposurec (NRS 2–20) | High (NRS > 8) | 198 (55.3) | 253 (43.0) | 1.6 (1.2–2.1)* | 81 (62.3) | 122 (56.5) | 1.2 (0.7–1.9) | 117 (51.3) | 131 (35.2) | 1.8 (1.3–2.6)* |
Low (NRS ≤ 8) | 160 (44.7) | 335 (57.0) | Reference | 49 (37.7) | 94 (43.5) | Reference | 111 (48.7) | 241 (64.8) | Reference | |
Cumulative cold exposured (NRS 2–20) | 1st quartile | 69 (19.3) | 141 (24.0) | Reference | 22 (16.9) | 34 (15.7) | Reference | 47 (20.6) | 107 (28.8) | Reference |
2nd quartile | 91 (25.4) | 194 (33.0) | 1.0 (0.7–1.5) | 27 (20.8) | 60 (27.8) | 0.8 (0.4–1.6) | 64 (28.1) | 134 (36.0) | 1.1 (0.7–1.8) | |
3rd quartile | 110 (30.7) | 147 (25.0) | 1.5 (1.04–2.3)* | 36 (27.7) | 62 (28.7) | 0.97 (0.5–1.9) | 74 (32.5) | 85 (22.8) |
1.9 (1.2–3.1)
| |
4th quartile | 88 (24.6) | 106 (18.0) | 1.6 (1.1–2.5)* | 45 (34.6) | 60 (27.8) | 1.1 (0.6–2.2) | 43 (18.9) | 46 (12.4) | 1.9 (1.1–3.4)* | |
Handling cold objects during work | Yes | 123 (33.5) | 108 (17.6) | 2.6 (1.9–3.6)* | 77 (57.0) | 73 (32.0) | 2.8 (1.8–4.5)* | 46 (19.8) | 35 (9.1) | 2.4 (1.5–3.9)* |
No | 244 (66.5) | 506 (82.4) | Reference | 58 (43.0) | 155 (68.0) | Reference | 186 (80.2) | 351 (90.9) | Reference | |
Extreme cold, wind or cooling moist during work | Yes | 133 (36.3) | 146 (23.8) | 2.3 (1.7–3.3)* | 85 (63.9) | 103 (45.2) | 2.4 (1.5–3.9)* | 48 (20.6) | 43 (11.1) | 2.2 (1.4–3.6)* |
No | 233 (63.7) | 468 (76.2) | Reference | 48 (36.1) | 125 (54.8) | Reference | 185 (79.4) | 343 (88.9) | Reference | |
Occupational HAV exposure measures | ||||||||||
Impact tools | Yes | 56 (15.2) | 47 (7.7) | 2.4 (1.5–3.9)* | 50 (37.3) | 40 (17.5) | 2.8 (1.7–4.6)* | 6 (2.6) | 7 (1.8) | 1.3 (0.4-4.0) |
No | 312 (84.8) | 567 (92.3) | Reference | 84 (62.7) | 188 (82.5) | Reference | 228 (97.4) | 379 (98.2) | Reference | |
Rapidly rotating tools | Yes | 14 (3.7) | 11 (1.8) | 1.9 (0.9–4.2) | 10 (7.6) | 7 (3.1) | 2.3 (0.9-6.0) | 4 (1.7) | 4 (1.0) | 1.3 (0.3–5.3) |
No | 352 (96.2) | 602 (98.2) | Reference | 122 (92.4) | 220 (96.9) | Reference | 230 (98.3) | 382 (99.0) | Reference | |
Forestry/gardening tools | Yes | 53 (14.5) | 75 (12.3) | 1.4 (0.9–2.2) | 47 (35.3) | 68 (29.8) | 1.4 (0.9–2.4) | 6 (2.6) | 7 (1.8) | 1.3 (0.4-4.0) |
No | 313 (85.5) | 537 (87.7) | Reference | 86 (64.7) | 160 (70.2) | Reference | 227 (97.4) | 377 (98.2) | Reference | |
Vibrating tools | Yes | 62 (16.8) | 65 (10.6) | 1.9 (1.2–2.9)* | 54 (40.6) | 58 (25.6) | 2.0 (1.2–3.2)* | 8 (3.4) | 7 (1.8) | 1.5 (0.5–4.2) |
No | 306 (83.2) | 548 (89.4) | Reference | 79 (59.4) | 169 (74.4) | Reference | 227 (96.6) | 379 (98.2) | Reference | |
Heavily vibrating tools | Yes | 54 (14.7) | 52 (8.5) | 2.4 (1.5–3.9)* | 51 (38.3) | 49 (21.7) | 2.5 (1.5–4.1)* | 3 (1.3) | 3 (0.8) | 1.6 (0.3–8.1) |
No | 313 (85.3) | 560 (91.5) | Reference | 82 (61.7) | 177 (78.3) | Reference | 177 (78.3) | 383 (99.2) | Reference | |
Vehicles with vibrating controls | Yes | 50 (13.6) | 66 (10.8) | 1.5 (0.95–2.3) | 42 (31.6) | 58 (25.4) | 1.5 (0.9–2.4) | 8 (3.4) | 8 (2.1) | 1.6 (0.6–4.2) |
No | 317 (86.4) | 547 (89.2) | Reference | 91 (68.4) | 170 (74.6) | Reference | 226 (96.6) | 377 (97.9) | Reference | |
Any HAV exposuree | Yes | 111 (30.3) | 131 (21.4) | 2.1 (1.4–3.0)* | 89 (66.4) | 107 (46.9) | 2.6 (1.6–4.3)* | 22 (9.5) | 24 (6.2) | 1.4 (0.8–2.6) |
No | 255 (69.7) | 482 (78.6) | Reference | 45 (33.6) | 121 (53.1) | Reference | 210 (90.5) | 361 (93.8) | Reference |
Multiple conditional logistic regression analyses (Table 4)
Factor | Exposure level | Cases | Controls | OR | (95% CI) | ||
---|---|---|---|---|---|---|---|
N
| % |
N
| % | ||||
All subjects | |||||||
Frostbite hands | Yes | 97 | 30 | 32 | 6 | 10.3 | (5.5–19.3)* |
No | 225 | 70 | 527 | 94 | Reference | – | |
Rheumatic diseasea | Yes | 58 | 18 | 36 | 6 |
3.1
| (1.7–5.7)* |
No | 264 | 82 | 523 | 94 | Reference | – | |
BMI category (kg/m2) | BMI < 18.5 | 5 | 2 | 5 | 1 | 1.1 | (0.1–9.9) |
18.5 ≤ BMI < 25 | 185 | 57 | 243 | 43 | Reference | – | |
BMI ≥ 25 | 132 | 41 | 311 | 56 |
0.4
| (0.3–0.6)* | |
Upper extremity nerve injury | Yes | 98 | 30 | 99 | 18 |
2.0
| (1.3-3.0)* |
No | 224 | 70 | 460 | 82 | Reference | – | |
Migraines | Yes | 51 | 16 | 42 | 8 |
2.4
| (1.3–4.3)* |
No | 271 | 84 | 517 | 92 | Reference | – | |
Vascular diseaseb | Yes | 101 | 31 | 142 | 25 |
1.9
| (1.2–2.9)* |
No | 221 | 69 | 417 | 75 | Reference | – | |
Men | |||||||
Frostbite hands | Yes | 51 | 39 | 13 | 6 |
17.9
| (6.1–52.1)* |
No | 79 | 61 | 209 | 94 | Reference | – | |
Any HAV exposurec | Yes | 87 | 67 | 103 | 46 |
2.2
| (1.2–4.2)* |
No | 43 | 33 | 119 | 54 | Reference | – | |
BMI category (kg/m2) | BMI < 18.5 | 0 | 0 | 0 | 0 | – | – |
18.5 ≤ BMI < 25 | 62 | 48 | 73 | 33 | Reference | – | |
BMI ≥ 25 | 68 | 52 | 149 | 67 |
0.4
| (0.2–0.8)* | |
Upper extremity nerve injury | Yes | 49 | 38 | 46 | 21 |
2.4
| (1.2–4.6)* |
No | 81 | 62 | 176 | 79 | Reference | – | |
Women | |||||||
Frostbite hands | Yes | 53 | 25 | 19 | 6 |
7.6
| (3.5–16.6)* |
No | 159 | 75 | 326 | 94 | Reference | – | |
Rheumatic diseasea | Yes | 45 | 21 | 23 | 7 |
4.2
| (1.9-9.0)* |
No | 167 | 79 | 322 | 93 | Reference | – | |
BMI category (kg/m2) | BMI < 18.5 | 5 | 2 | 5 | 1 | 1.5 | (0.2–13.4) |
18.5 ≤ BMI < 25 | 130 | 61 | 168 | 49 | Reference | – | |
BMI ≥ 25 | 77 | 36 | 172 | 50 |
0.5
| (0.3–0.8)* | |
Upper extremity nerve injury | Yes | 57 | 27 | 55 | 16 | 1.5 | (0.9–2.7) |
No | 155 | 73 | 290 | 84 | Reference | – | |
Migraines | Yes | 42 | 20 | 34 | 16 |
2.3
| (1.2–4.5)* |
No | 170 | 80 | 311 | 84 | Reference | – | |
Cumulative cold exposured | High (NRS > 8) | 106 | 50 | 119 | 34 |
1.6
| (1.04–2.4)* |
Low (NRS ≤ 8) | 106 | 50 | 226 | 66 | Reference | – |