Abstract 3675: Low Cholesterol Level and Increased Risk of Ischemic Stroke Mortality in Japan
BACKGROUND: Ischemic stroke is reduced with decreasing total cholesterol level in high risk patients. However, there are different subtypes of ischemic strokes and the prevalence of the subtypes of ischemic strokes varies between Japan and Western countries.
METHODS: We studied 16,461 subjects (mean age 54±13 years, men 26%) who had the annual health examination offered to adult citizens of Moriguchi city, Osaka, Japan in 1997. Low cholesterol level was defined as a serum total cholesterol level <160 mg/dL. The end of follow-up was the end of 2006. Proportional hazards regression analysis was used to assess the association of the low cholesterol level with ischemic stroke mortality.
RESULTS: During a mean follow-up of 8.5±2.1 years (median 9.2 years), there were 166 cardiovascular deaths, including 65 stroke deaths (36 ischemic, 20 hemorrhagic). Incidence of types of stroke according to total cholesterol level was presented in the figure⇓. Unadjusted proportional hazards regression analysis showed ischemic stroke mortality was significantly higher in the low cholesterol group (HR=3.7, 95%CI=1.7 to 8.1; p=0.0011), compared with the higher cholesterol group (≥160 mg/dL). After adjustment for age, sex, diabetes mellitus, smoking status and drinking habit, ischemic stroke mortality (HR=4.8, 95%CI=2.1 to 10.9; p=0.0002), stroke mortality (HR=3.9, 95%CI=2.1 to 7.6; p<0.0001), and cardiovascular mortality (HR=2.6, 95%CI=1.7 to 4.0; p<0.0001) were all significantly higher in the low cholesterol group.
CONCLUSIONS: In the general Japanese population, low cholesterol level was associated with higher ischemic stroke mortality.