Abstract 4154: Long-Term Change of Blood Pressure Before Cardiovascular Mortality: A Nested Case-Control Study
Background: Although many epidemiologic studies assessed the association between blood pressure change and the cardiovascular disease (CVD), information on the long-term blood pressure change before cardiovascular mortality with repeated blood pressure measurements is limited. We investigated the change of blood pressure over 14 years before deaths from CVD, in a large prospective cohort study.
Methods: We performed a nested case-control study in the Korea Medical Insurance Corporation Study Cohort. Since 1990 we measured blood pressure and major CVD risk factors every two years for 108461 men and 64119 women who were aged 35–59 years. Cause and date of deaths were obtained from the National Statistical Office, Korea. Cases were 1636 people who died from CVD between 1993 and 2004. Controls were 3272 survivors at the time of sampling. We sampled two controls per each case, using incidence-density sampling methods and matching for sex and age.
Results: People who died from CVD had higher blood pressures than their controls. These differences were statistically significant from 14 years before deaths (p<0.001 for all examinations). During the 14 years, systolic blood pressure significantly increased in people who died from CVD (p<0.001) but not in their controls (p=0.811). The annual increase in systolic blood pressure among cases was 0.60 mmHg during 0–7 years before death, and 0.22 mmHg during 8–14 years before death. Diastolic blood pressure did not significantly increase both in cases and controls.
Conclusion: These results support that both long-term blood pressure history and recent increase of blood pressure are associated with the risk of cardiovascular mortality.