Trends in blood pressure levels over time in middle-aged and elderly Jerusalem residents.

Change in blood pressure levels over time was investigated in Jerusalem, in two cross-sectional surveys in 1970 and in 1986 among residents of a neighbourhood aged 50 years and more. The study population comprised 1397 individuals in 1970 and 1858 in the 1986. Age-adjusted mean systolic and diastolic blood pressure levels were lower in 1986 than in 1970 by 6.9 mmHg and 4.7 mmHg, respectively. The prevalence of blood pressure levels above 160 and/or 95 mmHg in 1986 was lower by 50% and there was a twofold increase in current treatment for hypertension. The reduction in blood pressure in both sexes remained evident upon control for confounding effects of age, ethnic group, education, body mass index and reported treatment for hypertension. The proportion of people who had blood pressure levels below 140/90 and did not report being under treatment, increased. The possibility of methodological problems inherent in this type of study were considered. More effective antihypertensive treatment in 1986 can explain only part of the reduction. The decrease in levels of blood pressure as revealed by this study may reflect a real reduction in the population that could explain part of the striking decline in cardiovascular mortality in Israel.