Characteristics of welders and controls, and comparisons between groups
| Characteristics | Welders (n=101) | Controls (n=127) | p Value |
|---|---|---|---|
| Age (year) | 41 (23–60) | 43 (23–56) | 0.90* |
| BMI (kg/m2) | 27.7 (21.4–34.9) | 27.1 (22.3–34.2) | 0.48* |
| Ethnicity: European/others (European, %)† | 96/5 (95) | 122/5 (96) | 0.75‡ |
| Low/high education (low, %)§ | 94/7 (93) | 109/17 (87) | 0.032‡ |
| Cardiovascular disease: yes/no (yes, %)¶ | 23/78 (23) | 25/102 (20) | 0.63‡ |
| Family history of cardiovascular disease: yes/no (yes, %)** | 44/57 (44) | 46/81 (36) | 0.28‡ |
| Current residence: big city/others (big city, %)†† | 10/91 (10) | 29/98(23) | 0.013‡ |
| Previous smoking: yes/no (yes, %) | 43/58 (43) | 43/83 (34) | 0.21‡ |
| Passive smoking: yes/no (yes, %) | 29/72 (29) | 16/111 (13) | 0.0041‡ |
| Hobby with smoke: yes/no (yes, %) | 9/92 (9) | 5/122 (4) | 0.17‡ |
| Respirable dust (mg/m3)‡‡ | 1.1 (0.2–8.3) | 0.1 (0.0–0.2) | <0.001* |
| CpG_2 methylation (%) | 76.7 (71.5–83.0) | 76.5 (70.3–81.2) | 0.27* |
| CpG_3 methylation (%) | 78.5 (75.6–81.2) | 77.4 (74.1–82.7) | <0.001* |
| CpG_4 methylation (%) | 88.4 (77.0–94.2) | 88.9 (78.0–94.2) | 0.68* |
| CpG_5 methylation (%) | 87.1 (82.8–97.5) | 89.7 (81.8–97.1) | <0.001* |
Medians (5–95%) are presented, if not indicated otherwise.
*Between welders and controls (Mann-Whitney U test).
†Parents of the participants from Europe/others (%).
‡Between welders and controls (Fisher's exact test).
§Participants with high school or lower/university education, or higher.
¶Participants reported whether they had had myocardial infarction, angina pectoris, hypertension, stroke, blood clot or any other cardiovascular diseases diagnosed by their doctors.
**Participants were asked whether their parents or siblings were diagnosed by doctors for having myocardial infarction, stroke and/or hypertension before they were 65 years old.
††Big city/small city, villages.
‡‡Nineteen of the controls and 53 of the welders were monitored.
BMI, body mass index.