Blood pressure and cardiovascular morbidity and mortality in a Dutch population: The Nijmegen cohort study

Background. The objective was to determine the influence of systolic blood pressure and diastolic blood pressure on the development of coronary heart disease over an 18-year period in a Dutch general practice population. Methods. The Nijmegen Cohort Study is a prospective cohort study with an 18-year follow-up. In 1977 systolic blood pressure, diastolic: blood pressure, and other cardiovascular risk factors were measured in 7,092 Caucasians, men and women. The screening took place in six general practices, participating in a university registration network. Cardiovascular disease and all mortality was registrated during the 1977-1995 period. A Cox proportional haz ard model was performed separately for men and women with the first onset of a coronary heart disease as the outcome variable. Age, smoking, serum cholesterol, blood pressure, and socioeconomic class were included as independent variables. Results. During the 18-year follow-up period, 205 men and 63 women suffered a nonfatal myocardial infarction. During this time, 205 deaths were identified, of which 54 were cardiovascular. Of all deaths, 139 were noncardiovascular, of which 10% mere due to accident or suicide, while in 12 participants the cause of death was uncertain. The analysis indicated that both the systolic and the diastolic blood pressure were independently associated with the Likelihood for developing coronary heart disease, as were the other risk factors. For coronary heart disease, the significant risk ratios for the systolic blood pressure were 1.6 for men and 2.1 for women. For the diastolic blood pressure a risk ratio was found of 1.4 for men and 2.0 for women. Conclusion. A significant relation between blood pressure and coronary heart disease was demonstrated. As mean blood pressures, cholesterol levels, smoking habits, and socioeconomic class in this cohort did not differ from other figures in The Netherlands, extrapolation of the results to the Dutch population is possible. (C) 2001 American Health Foundation and Academic Press.