Basic characteristics of study groups
| Covariates | Controls (n=152)* | Chimney sweeps (n=151)* | Creosote-exposed workers (n=19)* | P value† |
| Age (years) | 43 (20–63) | 43 (19–66) | 32 (22–58) | 0.492 |
| BMI (kg/m2) | 27 (20–45) | 26 (19–37) | – | 0.019 |
| Relative telomere length | 0.57 (0.35–1.0) | 0.56 (0.36–0.97) | 0.57 (0.33–0.78) | 0.836 |
| Relative mitochondrial DNA copy number | 0.87 (0.54–1.7) | 0.83 (0.51–1.41) | 0.95 (0.43–1.34) | 0.162 |
| F2RL3_CpG1 | 89.5 (58–100) | 88.8 (55–99) | 87.2 (65–96) | 0.019 |
| F2RL3_CpG2 (cg03636183) | 76.7 (48–86) | 76.6 (45–83) | 73.3 (50–78) | 0.011 |
| AHRR_CpG1 | 75.0 (25–88) | 73.0 (21–90) | 74.1 (31–83) | 0.087 |
| AHRR_CpG2 | 69.1 (23–80) | 66.5 (20–77) | 68.7 (31–82) | 0.004 |
| AHRR_CpG3 (cg05575921) | 90.0 (35–100) | 88.1 (29–100) | 84.9 (37–94) | 0.006 |
| Cigarette smoking | ||||
| Current smoker | 25 (16.4) | 27 (17.9) | 3 (15.8) | 0.915 |
| Party/ former smoker | 44 (28.9) | 49 (32.5) | 6 (31.6) | |
| Never smoker | 83 (54.6) | 74 (49.0) | 9 (47.4) | |
| Snus (yes) | 29 (19.1) | 52 (34.4) | 6 (31.6) | 0.004 |
| Passive smoking (yes) | 24 (15.8) | 28 (18.5) | 5 (26.3) | 0.384 |
| Exposure from hobby (yes) | 6 (3.9) | 9 (6.0) | 2 (10.5) | 0.268 |
| Vegetables‡ (≥5 times per week) | 88 (57.9) | 96 (63.6) | 11 (57.9) | 0.609 |
| Fruits§ (≥5 times per week) | 88 (57.9) | 75 (49.7) | 10 (52.6) | 0.351 |
| Fish¶ (≥1 per week) | 70 (46.1) | 73 (48.3) | 9 (47.4) | 0.884 |
| Physical activity**(high) | 62 (40.8) | 73 (48.3) | 7 (36.8) | 0.370 |
| Education (higher than high school) | 31 (20.4) | 24 (15.9) | 0 (0)†† | 0.100 |
| Current residency (big city) | 70 (46.1) | 52 (34.4) | 11 (57.9)†† | 0.006 |
Values are median (min–max) for continuous variables or n (%) for categorical variable. The content of this table was previously reported (Alhamdow et al, 2018).
*Up to two missing cases for some of the variables.
†P value of Kruskal-Wallis test for continuous variables and Fisher’s exact test for categorical variables.
‡Intake of all kinds of vegetables, legumes and root vegetables (fresh, frozen, canned, stewed, juice, soup and so on).
§Intake of all kinds of fruits and berries (fresh, frozen, canned, juice, jam and so on).
¶Intake of all kinds of fish.
**At least 30 min per week of sudorific activities such as running and badminton during leisure time.
††Missing data for four participants.
BMI, body mass index.