Table 3.
Comparison of the serum TSH, FT4, FT3, and FT3/FT4 ratio between summer and winter season.
| Total | P value | EU | P value | SCH | P value | |
|---|---|---|---|---|---|---|
| TSH (mIU/l) | ||||||
| Summer | 2.93 ± 1.96 | 0.136 | 2.34 ± 1.25 | 0.382 | 6.64 ± 1.60 | 0.171 |
| Winter | 2.77 ± 1.79 | 2.25 ± 1.25 | 6.04 ± 1.17 | |||
|
| ||||||
| FT4 (ng/dl) | ||||||
| Summer | 1.23 ± 0.57 | 0.007 | 1.23 ± 0.15 | 0.063 | 1.21 ± 0.15 | 0.009 |
| Winter | 1.20 ± 0.16 | 1.21 ± 0.16 | 1.14 ± 0.14 | |||
|
| ||||||
| FT3 (pg/ml) | ||||||
| Summer | 3.23 ± 0.44 | <0.001 | 3.22 ± 0.44 | <0.001 | 3.27 ± 0.45 | 0.853 |
| Winter | 3.37 ± 0.39 | 3.39 ± 0.40 | 3.25 ± 0.32 | |||
|
| ||||||
| FT3/FT4 ratio | ||||||
| Summer | 2.68 ± 0.45 | <0.001 | 2.65 ± 0.45 | <0.001 | 2.81 ± 0.44 | 0.037 |
| Winter | 2.87 ± 0.43 | 2.84 ± 0.43 | 2.99 ± 0.43 | |||
The parameters are expressed as the mean ± SD, and the means are compared using a Paired sample t-test.