Observed correlations
The “Symmetric” model provides estimates of correlations, as estimated for MZ and DZ independently, and as all twins together (Table 2).
Table 2 present observed maximum likelihood correlations. Most rph correlations were statistically significantly different from 0, and about the same magnitude in both the MZ and DZ twins (except for the correlation between eosinophils and asthma which was 0.29 and significant in MZ twins but was –0.05 and non-significant in DZ twins), indicating that all variables are associated within individuals. All ICCs were statistically significantly different from 0 and higher in the MZ twins than in the DZ twins, indicating a heritable component for the univariate measures. All CTCTs had a higher magnitude in the MZ twins than in the DZ twins indicating that genes affect the association between all variables.