Table 2.
Hormone Concentrations of Thyroid-Stimulating Hormone, Triiodothyronine, and Thyroxine in Active Smokers, Passive Smokers, and Nonsmokers
| Analyte | TSH (mIU/L) | T4 (μg/dL) | T3 (ng/dL) |
|---|---|---|---|
| Reference interval | 0.5–3.5 | 4.7–12.0 | 78–217.4 |
| Active smokers (n = 79) | |||
| Mean ± SD | 1.40 | 7.8 ± 2.31 | 99.1 ± 36.9 |
| Median | 1.02a | 7.6b | 92.0 |
| 95% CI | 0.07–6.83 | 3.9–13.3 | 52.1–204.3 |
| Passive smokers (n = 53) | |||
| Mean ± SD | 1.30 | 8.1 ± 2.62 | 87.6 ± 30.5 |
| Median | 1.06 | 7.9 | 84.0 |
| 95% CI | 0.25–3.01 | 4.5–12.3 | 40–160.2 |
| Nonsmokers (nonexposed) (n = 105) | |||
| Mean ± SD | 1.5 | 8.9 ± 2.3 | 106.6 ± 32.9 |
| Median | 1.12 | 8.7 | 102.0 |
| 95% CI | 0.71–4.00 | 3.7–15.5 | 46.4–175.0 |
Pair-wise comparisons of the three study groups indicate statistically significant differences in serum T4 (p < 0.01) and T3 (p < 0.001) means for the comparison of each group with the other two groups.
a
Median TSH p < 0.001 for the comparison of each group with the other two groups.
b
Median T4 p < 0.0001 for the comparison of each group with the other two groups.
TSH, thyroid-stimulating hormone; T3, triiodothyronine; T4, thyroxine; CI, confidence interval; SD, standard deviation.