Table 2.
Prevalence of positive thyroid antibodies stratified by sex.
| Total | Male | Female | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| N | i-TgAb, n (%) | i-TPOAb, n (%) | d-Ab, n (%) | N | i-TgAb, n (%) | i-TPOAb, n (%) | d-Ab, n (%) | N | i-TgAb, n (%) | i-TPOAb, n (%) | d-Ab, n (%) | |
| Ages | ||||||||||||
| 6–8 | 759 | 7 (0.9) | 11 (1.4) | 14 (1.8) | 388 | 1 (0.3) | 2 (0.5) | 3 (0.8) | 371 | 6 (1.6) | 9 (2.4) | 11 (3.0) |
| 9–11 | 1955 | 64 (3.3) # | 42 (2.1) | 78 (4.0) # | 1023 | 20 (2.0) | 13 (1.3) | 24 (2.3) | 932 | 44 (4.7) # | 29 (3.1) | 54 (5.8) |
| 12–17 | 687 | 21 (3.1) # | 18 (2.6) | 29 (4.2) # | 361 | 5 (1.4) | 5 (1.4) | 9 (2.5) | 326 | 16 (4.9) # | 13 (4.0) | 20 (6.1) |
| χ2 | 11.890 | 2.501 | 8.438 | 5.627 | 2.014 | 3.982 | 7.345 | 1.398 | 4.987 | |||
| p | 0.003 | 0.286 | 0.015 | 0.060 | 0.365 | 0.137 | 0.025 | 0.497 | 0.083 | |||
| Region | ||||||||||||
| Urban | 2048 | 63 (3.1) | 48 (2.3) | 78 (3.8) | 1051 | 14 (1.3) | 10 (1.0) | 18 (1.7) | 997 | 49 (4.9) | 38 (3.8) | 60 (6.0) |
| Rural | 1353 | 29 (2.1) | 23 (1.7) | 43 (3.2) | 721 | 12 (1.7) | 10 (1.4) | 18 (2.5) | 632 | 17 (2.7) | 13 (2.1) | 25 (4.0) |
| χ2 | 2.693 | 1.652 | 0.944 | 0.327 | 0.727 | 1.320 | 4.925 | 3.926 | 3.327 | |||
| p | 0.101 | 0.199 | 0.331 | 0.568 | 0.394 | 0.251 | 0.026 | 0.048 | 0.068 | |||
| UIC, µg/L | ||||||||||||
| <100 | 548 | 17 (3.1) | 13 (2.4) | 21 (3.8) | 232 | 2 (0.9) | 4 (1.7) | 5 (2.2) | 316 | 15 (4.7) | 9 (2.8) | 16 (5.1) |
| 100–199.9 | 1094 | 26 (2.4) | 26 (2.4) | 38 (3.5) | 576 | 8 (1.4) | 7 (1.2) | 12 (2.1) | 518 | 18 (3.5) | 19 (3.7) | 26 (5.0) |
| 200–299.9 | 824 | 23 (2.8) | 19 (2.3) | 30 (3.6) | 456 | 6 (1.3) | 3 (0.7) | 7 (1.5) | 368 | 17 (4.6) | 16 (4.3) | 23 (6.3) |
| ≥300 | 935 | 26 (2.8) | 13 (1.4) | 32 (3.4) | 508 | 10 (2.0) | 6 (1.2) | 12 (2.4) | 427 | 16 (3.7) | 7 (1.6) | 20 (4.7) |
| χ2 | 0.820 | 3.080 | 0.209 | 1.330 | 1.891 | 0.942 | 1.243 | 5.505 | 1.095 | |||
| p | 0.845 | 0.379 | 0.976 | 0.741 | 0.594 | 0.830 | 0.743 | 0.138 | 0.778 | |||
| UI/Cr, µg/g | ||||||||||||
| <111.5 (Quartile 1) |
850 | 28 (3.3) | 23 (2.7) | 37 (4.4) | 439 | 10 (2.3) | 6 (1.4) | 13 (3.0) | 411 | 18 (4.4) | 17 (4.1) | 24 (5.8) |
| 111.5–241.8 (Quartile 2 + 3) |
1700 | 40 (2.4) | 37 (2.2) | 55 (3.2) | 892 | 8 (0.9) | 12 (1.3) | 15 (1.7) | 808 | 32 (4.0) | 25 (3.1) | 40 (5.0) |
| >241.8 (Quartile 4) |
851 | 24 (2.8) | 11 (1.3) | 29 (3.4) | 441 | 8 (1.8) | 2 (0.5) | 8 (1.8) | 410 | 16 (3.9) | 9 (2.2) | 21 (5.1) |
| χ2 | 1.964 | 4.287 | 2.137 | 4.370 | 2.890 | 2.560 | 0.154 | 2.557 | 0.445 | |||
| p | 0.374 | 0.117 | 0.343 | 0.112 | 0.236 | 0.278 | 0.926 | 0.278 | 0.800 | |||
# Significance between two subgroups using the chi-squared test with a Bonferroni correction, as well as chi-squared test results compared with results obtained from age 6–8 years, p < 0.05. Bold remarks indicate statistically significant differences. Abbreviations: UIC, urinary iodine concentration; UI/Cr, urinary iodine-to-creatinine ratio; TgAb, thyroglobulin antibody; TPOAb, thyroid peroxidase antibody; d-Ab, double-positive thyroglobulin antibody and thyroid peroxidase antibody.