Lifetime risk of stroke in young-aged andmiddle-aged Chinese population: the Chinese Multi-Provincial Cohort Study

Objective: Stroke is a major cause of premature death in China. Early prevention of stroke requires a more effective method to differentiate the stroke risk among young-aged and middle-aged individuals than the 10-year risk of cardiovascular disease. This study aimed to establish a lifetime stroke risk model and risk charts for the young-aged and middle-aged population in China. Methods: The Chinese Multi-Provincial Cohort Study participants (n = 21 953) aged 35-84 years without cardiovascular disease at baseline were followed for 18 years (263 016 person-years). Modified Kaplan-Meier method was used to estimate the mean lifetime stroke risk up to age of 80 years and the lifetime stroke risk according to major stroke risk factors for the population aged 35-60 years. Results: A total of 917 participants developed first-ever strokes. For the participants aged 35-40 years (98 stroke cases), the lifetime stroke risk was 18.0 and 14.7% in men and women, respectively. Blood pressure most effectively discriminated the lifetime stroke risk. The lifetime risk of stroke for the individuals with all risk factors optimal was 8-10 times lower compared with those with two or more high risk factors at age 35-60 years at baseline. Conclusion: In young-aged and middle-aged population, the lifetime stroke risk will keep very low if major risk factors especially blood pressure level is at optimal levels, but the risk substantially increases even with a slight elevation of major risk factors, which could not be identified using 10-year risk estimation.