Dynamics of obesity paradox after stroke, related to time from onset, age, and causes of death
ABSTRACT Paradoxical longevity in obese patients with established disease has been documented in various conditions. We aimed to find whether such a relationship exists in ischemic stroke patients, with stratified analyses according to time of death after stroke, age, and cause of death.
The Korean Stroke Registry (KSR) is a nationwide, multicenter, prospective registry of acute stroke. For 7.5 years, data on 34,132 patients with acute ischemic stroke were collected through KSR, and their mortality information was ascertained through a governmental statistical office. We assessed relative hazard of mortality according to obesity status.
Stroke survivors whose body mass index (BMI) values were lower than the chosen reference level of 20-23 had increased risks of long-term mortality (hazard ratio [HR] of 1.36 and 95% confidence interval [CI] of 1.25-1.48 for BMI ≤18.5; HR of 1.14 and 95% CI of 1.03-1.26 for BMI 18.5-20), whereas obese stroke patients had decreased risks of mortality (HR of 0.83 and 95% CI of 0.74-0.92 for BMI 27.5-30; HR of 0.77 and 95% CI of 0.63-0.93 for BMI 30-32.5). Inverse association between obesity status and mortality was not evident until 90 days after stroke but became significant 1 year after onset of stroke. Such an association was more prominent in stroke patients who were less than 65 years old, but it remained constant in all age groups. The paradoxical relationship remained significant, regardless of causes of death.
Our results documented obesity paradox in stroke survivors, regardless of age and causes of death, and it became evident a sufficient time after stroke onset.
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ABSTRACT: IMPORTANCE Reports of an obesity paradox have led to uncertainty about secondary prevention in obese patients with stroke. The paradox is disputed and has been claimed to be an artifact due to selection bias. OBJECTIVE To determine whether the obesity paradox in stroke is real or an artificial finding due to selection bias. DESIGN, SETTING, AND PARTICIPANTS We studied survival after stroke in relation to body mass index (BMI, calculated as weight in kilograms divided by height in meters squared). To overcome selection bias, we studied only deaths caused by the index stroke on the assumption that death by stroke reported on a death certificate was due to the index stroke if death occurred within the first month poststroke. We used the Danish Stroke Register, containing information on all hospital admissions for stroke in Denmark from 2003 to 2012, and the Danish Registry of Causes of Death. The study included all registered Danes (n = 71 617) for whom information was available on BMI (n = 53 812), age, sex, civil status, stroke severity, stroke subtype, a predefined cardiovascular profile, and socioeconomic status. MAIN OUTCOMES AND MEASURES The independent relation between BMI and death by the index stroke within the first week or month by calculating hazard ratios in multivariate Cox regression analysis and multiple imputation for cases for whom information on BMI was missing. RESULTS Of the 71 617 patients, 7878 (11%) had died within the first month; of these, stroke was the cause of death of 5512 (70%). Of the patients for whom information on BMI was available, 9.7% were underweight, 39.0% were of normal weight, 34.5% were overweight, and 16.8% were obese. Body mass index was inversely related to mean age at stroke onset (P < .001). There was no difference in the risk for death by stroke in the first month among patients who were normal weight (reference), overweight (hazard ratio, 0.96; 95% CI, 0.88-1.04), and obese (hazard ratio, 1.0; 95% CI, 0.88-1.13). Analysis of deaths within 1 week gave similar results. CONCLUSIONS AND RELEVANCE We found no evidence of an obesity paradox in patients with stroke. Stroke occurred at a significantly younger age in patients with higher BMI. Hence, obese patients with stroke should continue to aim for normal weight.JAMA Neurology 06/2014; 71(8). DOI:10.1001/jamaneurol.2014.1017 · 7.01 Impact Factor
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ABSTRACT: Background The impact of body mass index on acute ischemic stroke outcomes is unclear.Aims and/or hypothesisWe sought to determine the effect of body mass index on short-term (90 days) acute ischemic stroke outcomes.Methods Data were extracted for patients with acute ischemic stroke and records of body mass index at baseline from the Virtual International Stroke Trials Archive database. Multivariate logistic regression and Cox proportional hazard analysis were used to analyze effect of body mass index on poor functional outcome (modified Rankin Scale >2) and mortality, respectively, within 90 days of stroke's onset.ResultsOf the 4811 patients (mean age 68·8 ± 12·2 years) included in the study, 2002 (41·6%) were overweight, and 1095 (22·8%) were obese. Overweight (body mass index 25–29·9 kg/m2) was associated with decreased mortality (hazard ratios 0·59; 95% confidence interval 0·51–0·68; P < 0·01) and decrease in poor functional outcome (odds ratio 0·74; 95% confidence interval 0·64–0·85; P < 0·01) following acute ischemic stroke. The association of body mass index with stroke outcomes was dependent on age, gender, and use of thrombolytic therapy.Conclusions Being overweight or obese is associated with a better functional outcome and reduced mortality in patients of acute ischemic stroke. However, the definition of an ‘optimal’ body mass index, in relation to stroke outcomes, may be affected by age, gender, and use of thrombolytic therapy.International Journal of Stroke 07/2014; 9(5). DOI:10.1111/ijs.12168 · 4.03 Impact Factor
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ABSTRACT: Background: The role of body composition as a risk factor for death remains controversial in older persons. Objective: We determined the role of body-composition variables in mortality in older women. Design: Longitudinal analyses were performed in a prospective cohort study of older women. Participants were 4574 community-dwelling women aged >= 75 y at the baseline visit (between January 1992 and April 1994). Several body-composition variables were assessed by using anthropometric measures and dual-energy X-ray absorptiometry at the baseline visit. The main outcome was overall mortality. Body-composition variables were body mass index (BMI; in kg/m(2)), hip circumference, waist circumference, waist-to-hip ratio, fat mass/height(2), lean mass/height(2), percentage of fat mass, percentage of lean mass, and the lean mass:fat mass ratio. Results: The mean (+/- SD) age at baseline was 80.2 +/- 3.8 y. During the 17.7 y (IQR: 17.2-18.1 y) of follow-up, 2876 women died. U-shaped in crude analyses and reversed J-shaped relations in adjusted analyses between BMI, hip and waist circumferences, fat mass/height(2), and risk of death were shown. Adjusted risk of death was significantly higher in participants with BMI <= 24.6 and fat mass/height(2) kg/m(2). There was a negative linear association between fat mass (%) and risk of death: a 10% increase in fat mass was associated with a 12% reduction of mortality risk (adjusted HR: 0.88; 95% Cl: 0.84, 0.92; P < 0.001). Linear and statistically significant relations were shown between lean mass/height(2) and risk of death in crude but not adjusted analyses. Conclusions: Risk of mortality was consistently higher in older women with low adiposity. No lean mass indicator was associated with risk of death. Clinicians should be alerted by low adiposity in older women.American Journal of Clinical Nutrition 11/2014; 100(5):1352-60. DOI:10.3945/ajcn.114.086728 · 6.92 Impact Factor