The Bergen Blood Pressure Study: blood pressure changes, target organ damage and mortality in subjects with high and low blood pressure over 27 years.

Based on the Bergen population screening in 1963-64, 344 married couples (688 subjects), then aged 30-69 years, were included for studies in families with a history of hypertension or normotension. In 1990 430 subjects were available to a follow-up examination. The present paper describes 27-year mortality, blood pressure (BP) changes, cardiovascular disease and target organ damage in this population. In males who were hypertensive by the 1963-64 screening BP, the all-cause 27-year mortality was three times higher than in initially normotensive males (p < 0.05). From 1963-64 to 1990, the systolic BP was generally increased, whereas the diastolic BP was decreased in initially hypertensive and increased in initially normotensive subjects. In subjects who were hypertensive in 1963-64, the relative risk of hypertension in 1990 was more than seven times higher than in initially normotensive subjects (p < 0.05), cardiovascular events were reported more often (p < 0.001), and the mean electrocardiographic left ventricular voltage was higher (p < 0.01). Proteinuria was more frequent in initially hypertensive than normotensive males (p < 0.01). In summary, hypertension defined by a single BP recording at the 1963-64 screening was a risk factor for hypertension, cardiovascular morbidity and, for males, all-cause mortality 27 years later. With respect to offspring studies, our findings substantiate the classification of hypertensive and normotensive families. From 1963-64 to 1990, the BP status had changed in several couples, and the long observation period seems mandatory if a reliable definition of the family history of hypertension or normotension is to be obtained.