Combined Effect of High-Normal Blood Pressure and Low HDL Cholesterol on Mortality in an Elderly Korean Population: The South-West Seoul (SWS) Study

Abstract

BACKGROUND It is unclear whether prehypertension by the seventh Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC-7) criteria (systolic blood pressure (SBP) 120-139 or diastolic blood pressure (DBP) 80-89 mm Hg) or high-normal blood pressure (HNBP) by the European Society of Hypertension and European Society of Cardiology (ESH/ESC) criteria (SBP 130-139 or DBP 85-89 mm Hg) predicts mortality in elderly Koreans. We compared the mortality risk between those with prehypertension and HNBP and evaluated whether the presence of components of metabolic syndrome (MetS) can improve the prediction of mortality in subjects with HNBP. METHODS We analyzed all-cause and cardiovascular disease (CVD) mortality according to the JNC-7 and ESH/ESC categories using follow-up data of the South-West Seoul (SWS) Study, a prospective cohort study of 2,376 elderly Koreans, aged >60 years. RESULTS During the median follow-up of 7.6 years, 353 deaths occurred from all causes, and 113 of these were attributed to CVD. Prehypertension was nonsignificantly associated with an increased risk of mortality (hazard ratio (HR): 1.06, 95% confidence interval (CI): 0.68-1.64). Subjects with HNBP exhibited a nonsignificantly higher risk of mortality compared with those with optimal blood pressure by the ESH/ESC guideline (HR: 1.35, 95% CI: 0.84-2.18). However, the combination of low high-density lipoprotein (HDL) cholesterol and HNBP showed a twofold higher risk of all-cause mortality (HR: 2.01, 95% CI: 1.11-3.64) independent of other risk factors. CONCLUSIONS Although prehypertension was not associated with increased risk of mortality, individuals in the elderly Korean population with HNBP, especially when combined with low HDL cholesterol, showed a significantly increased risk of all-cause mortality.