Table 1.
General characteristics of participants.
| Characteristics | Total participants | P value | |
|---|---|---|---|
| Thyroid cancer | Control | ||
| Age group (years old, n, %) | 1.000 | ||
| 45–49 | 520 (11.2) | 2080 (11.2) | |
| 50–54 | 1335 (28.8) | 5340 (28.8) | |
| 55–59 | 1142 (24.7) | 4568 (24.7) | |
| 60–64 | 776 (16.8) | 3104 (16.8) | |
| 65–69 | 475 (10.3) | 1900 (10.3) | |
| 70–74 | 277 (6.0) | 1108 (6.0) | |
| 75–79 | 83 (1.8) | 332 (1.8) | |
| 80–84 | 23 (0.5) | 92 (0.5) | |
| ≥ 85 | 1 (0.0) | 4 (0.0) | |
| Sex (n, %) | 1.000 | ||
| Male | 993 (21.4) | 3972 (21.4) | |
| Female | 3639 (78.6) | 14,556 (78.6) | |
| Income (n, %) | 1.000 | ||
| 1 (lowest) | 604 (13.0) | 2416 (13.0) | |
| 2 | 515 (11.1) | 2060 (11.1) | |
| 3 | 733 (15.8) | 2932 (15.8) | |
| 4 | 959 (20.7) | 3836 (20.7) | |
| 5 (highest) | 1821 (39.3) | 7284 (39.3) | |
| Region of residence (n, %) | 1.000 | ||
| Urban | 2216 (47.8) | 8864 (47.8) | |
| Rural | 2416 (52.2) | 9664 (52.2) | |
| Obesity (BMI, kg/m2, n, %) | < 0.001* | ||
| < 18.5 (underweight) | 64 (1.4) | 393 (2.1) | |
| ≥ 18.5 to < 23 (normal) | 1524 (32.9) | 6911 (37.3) | |
| ≥ 23 to < 25 (overweight) | 1315 (28.4) | 5016 (27.1) | |
| ≥ 25 to < 30 (obese I) | 1533 (33.1) | 5613 (30.3) | |
| ≥ 30 (obese II) | 196 (4.2) | 595 (3.2) | |
| Smoking status (n, %) | < 0.001* | ||
| Nonsmoker | 4030 (87.0) | 15,785 (85.2) | |
| Past smoker | 348 (7.5) | 1145 (6.2) | |
| Current smoker | 254 (5.5) | 1598 (8.6) | |
| Alcohol consumption (n, %) | 0.008* | ||
| < 1 time a week | 3515 (75.9) | 14,398 (77.7) | |
| ≥ 1 time a week | 1117 (24.1) | 4130 (22.3) | |
| Charlson comorbidity index (n, %) | < 0.001* | ||
| 0 | 2882 (62.2) | 14,597 (78.8) | |
| 1 | 755 (16.3) | 2155 (11.6) | |
| 2 | 279 (6.0) | 903 (4.9) | |
| 3 | 105 (2.3) | 397 (2.1) | |
| ≥ 4 | 611 (13.2) | 476 (2.6) | |
| Total cholesterol (mg/dL, mean, SD) | 199.4 (37.8) | 202.1 (37.6) | < 0.001* |
| SBP (mmHg, mean, SD) | 124.1 (15.5) | 123.3 (15.6) | 0.003* |
| DBP (mmHg, mean, SD) | 77.2 (10.2) | 76.6 (10.2) | 0.001* |
| Fasting blood glucose (mg/dL, mean, SD) | 98.5 (24.8) | 0.061 | |
| Meteorological and air pollution data (mean, SD) | |||
| Mean temperature for 3 years (1095 days) (°C) | 12.9 (1.2) | 12.9 (1.2) | 0.005* |
| Highest temperature for 3 years (1095 days) (°C) | 18.0 (1.1) | 18.0 (1.1) | 0.008* |
| Lowest temperature for 3 years (1095 days) (°C) | 8.6 (1.6) | 8.5 (1.7) | 0.022* |
| Temperature range for 3 years (1095 days) (°C) | 9.4 (1.4) | 9.4 (1.4) | 0.556 |
| Relative humidity for 3 years (1095 days) (%) | 65.5 (4.6) | 65.5 (4.4) | 0.424 |
| Ambient atmospheric pressure for 3 years (1095 days) (hPa) | 1006.4 (4.0) | 1006.1 (4.4) | < 0.001* |
| Sunshine duration for 3 years (1095 days) (hr) | 5.8 (0.4) | 5.8 (0.3) | 0.003* |
| Rainfall for 3 years (1095 days) (mm) | 8.7 (0.9) | 8.6 (0.9) | 0.019* |
| SO2 for 3 years (1095 days) (ppb) | 5.3 (1.0) | 5.3 (1.0) | 0.073 |
| NO2 for 3 years (1095 days) (ppb) | 24.1 (8.7) | 24.2 (8.7) | 0.495 |
| O3 for 3 years (1095 days) (ppb) | 23.7 (4.6) | 23.4 (4.5) | 0.001* |
| CO for 3 years (1095 days) (ppb) | 525.4 (80.0) | 530.7 (80.6) | < 0.001* |
| PM10 for 3 years (1095 days) (μg/m3) | 51.9 (6.4) | 52.7 (6.5) | < 0.001* |
BMI body mass index (kg/m2); ppb parts per billion; SD standard deviation.
*Chi-square test or independent t test. Significance at P < 0.05.