Large-Scale Cohort Study on the Relationship Between Serum Lipid Concentrations and Risk of Cerebrovascular Disease Under Low-Dose Simvastatin in Japanese Patients With Hypercholesterolemia

BACKGROUND: The Japan Lipid Intervention Trial was a nationwide cohort study of 52,421 hypercholesterolemic patients treated with open-labeled simvastatin for 6 years under standard clinical practices. Cerebrovascular disease (CVD) is one of the leading causes of death in Japan, but the effect of hypercholesterolemia on CVD has not been well established in Japanese patients. This study aimed to determine the relationship between the risk of CVD and serum lipid concentrations during treatment in Japan. METHODS AND RESULTS: Patients were treated with 5-10 mg/day of simvastatin and all, including those who discontinued simvastatin for any reason, had their lipid concentrations and incidence of CVD monitored for 6 years. Data of 41,088 patients were analyzed in this study, excluding those who had a history of coronary heart disease or CVD. The risk of cerebral infarction was higher in patients whose mean total cholesterol concentrations during treatment were > or = 240 mg/dl, low-density lipoprotein cholesterol concentrations > or = 160 mg/dl, triglycerides > or = 150 mg/dl and high-density lipoprotein cholesterol concentrations <40 mg/dl. There was no obvious correlation between cerebral hemorrhage and serum lipid concentrations. CONCLUSION: Improvement of serum lipid concentrations is important for reducing the incidence of cerebral infarction.