The influence of genetics and household environment upon the variability of normal blood pressure: the Montreal Adoption Survey.

The Montreal Adoption Survey was conducted as a cross-sectional epidemiologic study of cardiovascular risk factors in French Canadian families. Analysis included blood pressure readings of 756 adopted and 445 natural children as well as 1176 parents. A genetic model was applied to the analysis of our data. Interindividual variability of blood pressure was studied and observed correlatives of systolic and diastolic pressure of parental and non parental subjects were calculated. Based on the maximum likelihood estimates presented in the models the explanation of the parent offspring and the between sibs expected population correlatives for systolic blood pressure was the following: 61% was due to shared genes and 39% to environment shared by both parents and children. For diastolic blood pressure the explanation between parents and offspring was the following: 58% was due to shared genes and 42% due to shared environment across generation. The explanation between sibs was estimated to be the following: 33% due to generation, 24% to shared environment across generation and 43% to shared environment within generation.