Abstract 10: Rising Trend of Ischemic Stroke in the Young

Abstract

Background: Stroke in patients under 45 years of age occurs less frequently than in older patients but its impact on the individual and society is greater. Recent studies have reported decreasing trends of acute ischemic stroke hospitalization. However, it is less clear what the trends are in different age groups and across different races. We sought to determine trends of ischemic stroke by age, gender and race in a large multi-ethnic population. Methods: Northern California Kaiser Permanente (KPNC) is a large multi-ethnic health care system that serves over 3 million members. Membership demographics, socio-economic and racial-ethnic distributions are representative of California. Study patients were identified by primary discharge ICD-9 codes (433.01, 433.11, 433.21, 433.31, 433.81, 433.91, 434.01, 434.11, 434.91 and 436) for the period of January 2000 - December 2008. Only one stroke per person per year was included in the analyses. Age-adjusted stroke rates standardized to the 2000 US Census population were calculated. Poisson regression analysis was used to examine trend data. Results: From 2000-2008, a total of 25,433 ischemic strokes and 28,438,488 person-years were included in the analyses. Age-adjusted rates of ischemic stroke decreased from 203 to 145 per 100,000 during this time (p<0.001). Rates decreased across all races during study period with the greatest drop among African Americans (from 313 to 261 per 100,000; p<0.001). Decreasing trends were similar between males and females across races. However, ischemic stroke rates among ages 25-44 were on the rise during this time (p<0.001), in particular for Black (from 17 to 39 per 100,000) and for Asian/Pacific Islanders (from 5 to 11 per 100,000) [ Figure ]. Conclusions: While the overall trend in KPNC showed a decrease in age-adjusted rates for ischemic stroke from 2000-2008, this was mainly true for age ≥ 65 years. There was an alarming rise in the number of ischemic strokes among patients age 25-44 years. Further studies to assess the trends of vascular risk factors such as obesity, hypertension and diabetes are needed to identify future stroke prevention targets in this age group.