Table 1. Characteristics of the sample according to quintiles of TSH.
| Total | TSH | p-value | ||||||
|---|---|---|---|---|---|---|---|---|
| First quintile (<1.34 mIU/L) | Second quintile (1.34-1.84 mIU/L) | Third quintile (1.84-2.38 mIU/L) | Fourth quintile (2.38-3.29 mIU/L) | Fifth quintile (≥3.29 mIU/L) | ||||
| N | 9649 | 1892 | 1923 | 1936 | 1946 | 1952 | ||
| Psoriasis, yes (%) | 270 (2.8%) | 40 (2.1%) | 50 (2.6%) | 60 (3.1%) | 64 (3.3%) | 56 (2.9%) | 0.204 | |
| Age (years-old), median (IQR) | 58.0 (53.0-65.0) | 58.0 (52.0-65.0) | 57.0 (52.0-64.0) | 58.0 (52.0-64.0) | 58.5 (53.0-66.0) | 60.0 (54.0-67.0) | <0.001 | |
| FT4 (ng/dL), median (IQR) | 1.18 (1.08-1.29) | 1.20 (1.10-1.32) | 1.19 (1.09-1.31) | 1.18 (1.08-1.29) | 1.17 (1.07-1.29) | 1.15 (1.05-1.26) | <0.001 | |
| FT3 (ng/dL), median (IQR) | 0.31 (0.28-0.33) | 0.31 (0.28-0.33) | 0.31 (0.28-0.33) | 0.31 (0.28-0.33) | 0.31 (0.28-0.33) | 0.31 (0.28-0.33) | 0.914 | |
| TPOAb positivity, n (%) | <0.001 | |||||||
| No | 8856 (91,8%) | 1780 (94,1%) | 1795 (93,3%) | 1807 (93,3%) | 1790 (92,0%) | 1684 (86,3%) | ||
| Yes | 793 (8,2%) | 112 (5,9%) | 128 (6,7%) | 129 (6,7%0 | 156 (8,0%) | 268 (13,7%) | ||
| Sex, n (%) | 0.008 | |||||||
| Men | 4605 (47.7%) | 838 (44.3%) | 931 (48.4%) | 930 (48.0%) | 928 (47.7%) | 978 (50.1%) | ||
| Women | 5044 (52.3%) | 1054 (55.7%) | 992 (51.6%) | 1006 (52.0%) | 1018 (52.3%) | 974 (49.9%) | ||
| Race/ethnicity, n (%) | <0.001 | |||||||
| Black | 1526 (16.0%) | 424 (22.8%) | 318 (16.7%) | 324 (17.0%) | 250 (13.0%) | 210 (10.9%) | ||
| Mixed | 2774 (29.1%) | 581 (31.3%) | 583 (30.7%) | 554 (29.0%) | 534 (27.7%) | 522 (27.0%) | ||
| White | 4883 (51.2%) | 798 (43.0%) | 925 (48.7%) | 959 (50.2%) | 1071 (55.5%) | 1130 (58.5%) | ||
| Asian | 256 (2.7%) | 41 (2.2%) | 50 (2.6%) | 53 (2.8%) | 60 (3.1%) | 52 (2.7%) | ||
| Indigenous | 90 (0.9%) | 13 (0.7%) | 24 (1.3%) | 20 (1.0%) | 14 (0.7%) | 19 (1.0%) | ||
| Education, n (%) | 0.001 | |||||||
| Less than high-school | 1059 (11.0%) | 193 (10.2%) | 201 (10.5%) | 218 (11.3%) | 207 (10.6%) | 240 (12.3%) | ||
| High-school and some college | 3423 (35.5%) | 746 (39.4%) | 713 (37.1%) | 660 (34.1%) | 658 (33.8%) | 646 (33.1%) | ||
| Complete college or more | 5167 (53.5%) | 953 (50.4%) | 1009 (52.5%) | 1058 (54.6%) | 1081 (55.5%) | 1066 (54.6%) | ||
| Smoking, n (%) | <0.001 | |||||||
| Never | 5826 (60.6%) | 1083 (57.5%) | 1153 (60.2%) | 1189 (61.7%) | 1207 (62.1%) | 1194 (61.3%) | ||
| Past | 2879 (29.9%) | 522 (27.7%) | 574 (30.0%) | 561 (29.1%) | 603 (31.0%) | 619 (31.8%) | ||
| Current | 912 (9.5%) | 280 (14.9%) | 187 (9.8%) | 178 (9.2%) | 133 (6.8%) | 134 (6.9%) | ||
a
Chi-square test;
b
Kruskal Wallis test