Table 3. Risk of Metabolic Syndrome in Euthyroid Subjects according to Thyroid Hormone Quartiles.
| Thyroid hormone category | Metabolic syndrome/total, n (%) | OR (95% CI) | ||
|---|---|---|---|---|
| Model 1 | Model 2 | Model 3 | ||
| TSH quartiles, mU/L | ||||
| 0.4-1.4 | 481/3,744 (13) | 1 | 1 | 1 |
| 1.5-2.1 | 395/3,414 (12) | 0.888 (0.747-1.055) | 0.919 (0.772-1.095) | 0.926 (0.727-1.178) |
| 2.2-3.0 | 423/3,085 (14) | 1.078 (0.909-1.279) | 1.170 (0.983-1.391) | 1.245 (0.982-1.577) |
| 3.1-5.0 | 365/3,253 (11) | 0.857 (0.719-1.023) | 1.016 (0.848-1.217) | 1.134 (0.887-1.452) |
| T3 quartiles, nmol/L | ||||
| 1.10-1.51 | 323/3,307 (10) | 1 | 1 | 1 |
| 1.52-1.69 | 403/3,373 (12) | 1.254 (1.074-1.464)† | 1.217 (1.040-1.424)‡ | 1.025 (0.829-1.268) |
| 1.70-1.89 | 415/3,470 (12) | 1.255 (1.076-1.464)† | 1.169 (1.001-1.366)‡ | 1.000 (0.809-1.235) |
| 1.90-2.90 | 523/3,346 (16) | 1.712 (1.476-1.984)* | 1.570 (1.351-1.824)* | 1.249 (1.020-1.529)† |
| T4 quartiles, nmol/L | ||||
| 64.0-96.0 | 481/3,631 (13) | 1 | 1 | 1 |
| 96.1-107.0 | 390/3,387 (12) | 0.852 (0.716-1.014) | 0.870 (0.730-1.038) | 0.867 (0.685-1.097) |
| 107.1-119.5 | 354/3,153 (11) | 0.828 (0.693-0.990)† | 0.814 (0.680-0.975)† | 0.746 (0.582-0.956)† |
| 119.6-155.0 | 439/3,325 (13) | 0.996 (0.841-1.180) | 0.942 (0.794-1.119) | 0.890 (0.706-1.121) |
| T3-to-T4 ratio quartiles | ||||
| 0.0060-0.0140 | 333/3,379 (10) | 1 | 1 | 1 |
| 0.0141-0.0159 | 375/3,406 (11) | 1.132 (0.936-1.368) | 1.132 (0.934-1.371) | 1.097 (0.843-1.428) |
| 0.0160-0.0179 | 428/3,329 (13) | 1.350 (1.122-1.624)* | 1.358 (1.126-1.638)* | 1.275 (0.988-1.646) |
| 0.0180-0.0565 | 528/3,382 (16) | 1.692 (1.416-2.022)* | 1.616 (1.349-1.936)* | 1.458 (1.141-1.863)* |
Model 1, unadjusted; Model 2, adjusted for sex and age; Model 3, adjusted for sex, age, body fat percentage, smoking and homeostasis model assessment of insulin resistance. OR and 95% CI for metabolic syndrome were estimated using logistic regression models. All P values and 95% CI for OR were corrected by Bonferroni's method due to multiple testing.
OR, odds ratio; CI, confidence interval; TSH, thyroid stimulating hormone; T3, triiodothyronine; T4, thyroxine.
*P<0.001; †0.001≤P<0.01; ‡0.01≤P<0.05.