Blood Pressure, Low-Density Lipoprotein Cholesterol, and Incidences of Coronary Artery Disease and Ischemic Stroke in Japanese: The Suita Study

Cardiovascular disease is a leading cause of mortality and morbidity in Asian countries.1 Elevated blood pressure (BP)1–5 and hypercholesterolemia1,6–10 are well-established independent cardiovascular risk factors. Moreover, the combination of these risk factors is a better predictor of the risk of cardiovascular disease in Western populations.11,12 In Japan, the Japan Lipid Intervention Trial (J-LIT) study showed that Japanese hypercholesterolemia patients with high systolic BP (SBP; ≥130mm Hg) and high total cholesterol levels (≥220mg/dl) treated with low-dose simvastatin had an increased risk of cardiovascular disease events.13 In Asia, the Asia Pacific Cohort Studies Collaborations (APCSC) demonstrated that the combination of high SBP (≥130mm Hg) and high total cholesterol (≥212mg/dl) increased the risks of fatal and nonfatal cardiovascular disease among both Western and Asian populations.14 However, the J-LIT and APCSC studies have some drawbacks, including relatively short follow-up periods (mean follow-up period of approximately 6 years) and lipid profiles based on total cholesterol and not low-density lipoprotein cholesterol (LDL-C). Furthermore, the J-LIT study was a patient-based clinical trial,13 and the APCSC study14 did not exclusively involve Asian populations, which have a higher incidence of stroke and lower incidence of coronary artery disease (CAD) than Western populations.1 The purpose of our study was to examine whether the relationship between BP and CVD outcomes (CAD and ischemic stroke) is modified by LDL-C levels in a community-based cohort study in a Japanese population.