Table 3. Genotype by sex interaction on variance of TSH and fT4 levels.
| Traits | Adjustment for environmental covariates | Full model | Nested models | |||||
|---|---|---|---|---|---|---|---|---|
| ρgMF = 1 | aσgM = σgF | |||||||
| -2 log-Likelihood | -2 log-Likelihood | χ2 | P-value | -2 log-Likelihood | χ2 | P-value | ||
| TSH | Nob | 2116.24 | 2116.25 | 0.00 | 0.478 | 2120.59 | 4.35 | 0.037 |
| Yesc | 1848.10 | 1848.10 | 0.00 | 0.500 | 1853.13 | 5.03 | 0.025 | |
| Ft4 | Nob | 1867.06 | 1867.07 | 0.01 | 0.455 | 1867.99 | 0.93 | 0.335 |
| Yesc | 1587.16 | 1587.16 | 0.00 | 0.500 | 1588.00 | 0.84 | 0.359 | |
Abbreviation: ρgMF, genetic correlation between males and females; σgM, genetic standard deviation in males; σgF, genetic standard deviation in females.
aRejection of null hypothesis (p value < 0.05) indicates that the magnitude of genetic effect differed between sexes.
bAdjusted for age, age2, and sex only.
cAdjusted for age, sex, BMI, smoking status, log-transformed urinary iodine/creatinine ratio, and menopausal status (males were regarded not to have menopausal status); only subjects without any missing values of covariates were included (n = 2028).
Statistically significant (p < 0.05) values are in boldface.