Table 6 Twin pair correlations and univariate twin structural equation model parameter estimates (unstandardized) for BP, normal weight and overweight subjects

From: Genetic and environmental influences on blood pressure and body mass index in Han Chinese: a twin study

 

N (pairs)

Correlations

   

Total

Variables

MZ/DZ

r MZ

r DZ

a 2

c 2

e 2

variance

SBP

 Normal weight

357/195

0.68

0.43

0.53

0.27

0.40

1.20

 Overweight

140/76

0.65

0.52

0.53

0.60

0.58

1.71

 P-valuea

   

0.989

0.293

0.006

 

DBP

 Normal weight

357/195

0.59

0.42

0.41

0.46

0.63

1.50

 Overweight

140/76

0.63

0.50

0.33

0.62

0.59

1.54

 P-valuea

   

0.796

0.588

0.526

 
  1. Abbreviations: a2, additive genetic effects; BP, blood pressure; c2, common environmental effects; DBP, diastolic blood pressure; DZ, dizygotic; e2, unique environmental effects; MZ, monozygotic.
  2. aP-value: P-value is shown for the χ2 difference (1 d.f.) between the full ACE model with BMI differences and the ACE sub–model, in which normal weight and overweight parameter estimates are set equal, that is, a2 (normal weight)=a2 (overweight), then c2 (normal weight)=c2 (overweight) and then e2 (normal weight)=e2 (overweight), respectively.
  3. Normal weight: BMI<24 kg m−2; overweight: BMI⩾24 kg m−2.
  4. SBP and DBP were log-transformed and adjusted for age, sex and study site.
Back to article page