Abstract 3206: Obesity Paradox in Acute Ischemic Stroke: Analysis of 34,132 Patients from Korean Stroke Registry
Background. Paradoxical longevity in obese patients with established disease has been reported in various conditions. However, detailed investigations involving acute ischemic stroke patients are scarce. We aimed to detect obesity paradox in acute ischemic stroke patients with stratified analyses based on age and causes of mortality.
Methods. Korean Stroke Registry (KSR) is a nationwide, multicenter and prospective registry of acute stroke. During 7.5 years, 34 132 acute ischemic stroke patients were collected through 30 participating centers. The mortality information was ascertained through a governmental statistical office, as current of December 2009. Multiple imputation by IVEware was used to estimate missing data on the basis of observed information and to account for potential variance due to uncertainty of missingness.
Results. Among a total of 34,132 acute ischemic stroke patients analyzed in this study, 1,348 patients (4.7%) were classified as underweighted (BMI <18.5), 10,888 (37.7%) as normal weight (18.5 - 22.9), 7,666 (26.5%) as overweight (23 - 24.9), 8,056 (27.9%) as obesity I (25.0 - 29.9), and 924 (3.2%) as obesity II (≥30; BMI missing in 5,250 patients), at the time of admission. During mean follow-up of 32.6 ± 23.1 months, 9,073 patients (26.6%) were deceased up to June 2009. Mortality rates of the included patients at various time-points were as followed; 4.1% (1,410 subjects) at 1-month, 7.0% (2,394) at 3-month, and 13.0% (4,373) at 1-year after stroke. Compared with body mass index (BMI) value of 20 - 23, stroke survivors with lower BMI values had increased risk of mortality (HR 1.36, 95% CI 1.25 - 1.48 for BMI ≤18.5; HR 1.14, 95% CI 1.03 - 1.26 for BMI 18.5 - 20). Likewise, obese stroke patients had decreased risk of mortality (HR 0.83, 95% CI 0.74 - 0.92 for BMI 27.5 - 30; HR 0.77, 95% CI 0.63 - 0.93 for BMI 30 - 32.5; see Figure). Inverse association between obesity status and mortality was not evident until 90 days after stroke, but became significant 1 year after onset of stroke. The association between obesity status and mortality was stronger in young-age group than in old-age group, but significance was maintained through all age-strata. The obesity paradox remained significant regardless of mortality causes, such as cancer death, vascular death and other causes of death.
Conclusion. From our study, an inverse association between obesity status and long-term mortality in stroke survivors was documented, and such association was evident regardless of age or causes of death.
- © 2012 by American Heart Association, Inc.