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Familial aggregation of blood pressure in 558 adopted children
Insights
Genetic factors significantly influence blood pressure resemblance within families. Studies show strong correlations between parents and natural children, but not adopted children, indicating heredity
Area of Science:
- Cardiovascular Genetics
- Human Physiology
- Family Studies
Background:
- Familial resemblance in blood pressure is observed, but the extent to which it is due to genetic or environmental factors is debated.
- Understanding the heritability of blood pressure is crucial for identifying individuals at risk and developing preventive strategies.
Purpose of the Study:
- To investigate the relative contributions of heredity and environment to familial resemblance in blood pressure.
- To compare the correlation of blood pressure between parents and natural children versus parents and adopted children.
Main Methods:
- Blood pressure was measured in 398 French-Canadian families with at least one adopted child.
- Age- and sex-adjusted scores were used for comparisons between parents and index children (natural or adopted).
- Correlations were analyzed between parents and natural children, parents and adopted children, and between siblings (natural and adopted).
Main Results:
- A highly significant correlation was found between parents' and natural children's blood pressure (10.2% systolic, 13.7% diastolic).
- Correlations between parents and adopted children were nonsignificant (0.81% systolic, 1.0% diastolic).
- Significant correlations were observed between pairs of natural children (7.84% systolic, 8.41% diastolic), but not between pairs of adopted children.
Conclusions:
- Heredity plays a substantial role in the familial resemblance of blood pressure.
- Environmental factors appear to have a minimal impact on blood pressure resemblance between parents and adopted children within this cohort.
Abstract:
Blood pressure was measured in each member of 398 French-Canadian families with at least one adopted child of the same ethnic origin. Measurements were made at home by a nurse, usually with the subject seated. One comparison per family between parents and randomly chosen index children was made, using age- and sex-adjusted scores. The correlation in blood pressure scores between parents and natural children was highly significant (P less than 0.001), at 10.2% for systolic and 13.7% for diastolic in 140 homes with at least one natural child, but the correlation between parents and adopted children was nonsignificant, at 0.81% and 1.0%, in 398 homes with at least one adopted child. The correlation between pairs of natural children was significant (P less than 0.05), at 7.84% for systolic and 8.41% for diastolic, in 80 homes with more than one natural child but nonsignificant, at 0.49% and 1.69%, respectively, for pairs of adopted children in 138 families with more than one adopted child. It is concluded that heredity explains most of the familial resemblance of blood pressure in children.