The Bergen Blood Pressure Study: definition of hypertensive and normotensive families based on 27 years' follow-up.

The familial aggregation of hypertension is well documented. However, many studies on the familial predisposition have suffered from insufficient knowledge of parental blood pressure (BP). In the present study, the family history is defined according to parental data from two BP surveys conducted almost 30 years apart. Data from a population screening in Bergen in 1963-64 were linked with information on marital status to define couples with or without a history of hypertension. Within the screened population a total of 344 married couples, 688 individuals, matched defined age and BP criteria. Four hundred and thirty individuals, representing 270 of the 344 families initial included (79%), attended a follow-up examination in 1990. Six hundred and ninety-one offspring were registered. In all families represented at follow-up, parental BP data from the 1963-64 screening were available. In 160 families (noffspring = 393), both parents also attended the follow-up examination in 1990. In 23 families (noffspring = 54) both parents were hypertensive in 1963-64 as well as in 1990. In 22 families (noffspring = 55) both parents were normotensive at both examinations. Thus, a family data base which is assumed to be useful for studies on offspring with or without a family history of hypertension, has been established. The offspring studies include BP, 24-h ambulatory BP, electrocardiography, echocardiography, endocrine parameters, electrolytes and anthropometric variables.