Concordance of blood pressure in spouses.

It has been known for some years that familial aggregation of blood pressure levels occurs in adults. The question of how much of this aggregation can be attributed to genetical inheritance, and how much to a shared environment, is not yet resolved. Evidence of the influence of a common environment on blood pressure levels can be gained from examining spouses who are not genetically related. In a family study of blood pressure levels in children, 452 of the parents had had a single continuous marriage. These spouses had a small but significant association with respect to blood pressure, and this association varied with length of marriage. Different interpretations of this result are discussed in relation to those from longitudinal studies.