Background and Purpose—
The observation that smokers with stroke could have better outcome than nonsmokers led to the term “smoking paradox.” The controversy of such a complex claim has not been fully settled, even though different case mix was noted. Analyses were conducted on 2 independent data sets to evaluate and determine whether such a paradox truly exists.
Methods—
Taiwan Stroke Registry with 88 925 stroke cases, and MJ cohort with 541 047 adults participating in a medical screening program with 1630 stroke deaths developed during 15 years of follow-up (1994–2008). Primary outcome for stroke registry was functional independence at 3 months by modified Rankin Scale score ≤2, for individuals classified by National Institutes of Health Stroke Scale score at admission. For MJ cohort, mortality risk by smoking status or by stroke history was assessed by hazard ratio.
Results—
A >11-year age difference in stroke incidence was found between smokers and nonsmokers, with a median age of 60.2 years for current smokers and 71.6 years for nonsmokers. For smokers, favorable outcome in mortality and in functional assessment in 3 months with modified Rankin Scale score ≤2 stratified by the National Institutes of Health Stroke Scale score was present but disappeared when age and sex were matched. Smokers without stroke history had a ≈2-fold increase in stroke deaths (2.05 for ischemic stroke and 1.53 for hemorrhagic stroke) but smokers with stroke history, 7.83-fold increase, overshadowing smoking risk. Quitting smoking at earlier age reversed or improved outcome.
Conclusions—
“The more you smoke, the earlier you stroke, and the longer sufferings you have to cope.” Smokers had 2-fold mortality from stroke but endured stroke disability 11 years longer. Quitting early reduced or reversed the harms.
Objective: Stroke in young adults is uncommon, and the etiologies and risk factors of stroke in young adults differ from those in older populations. Smoker's paradox is an unexpected favorable outcome, and age difference is used to explain the association between smoking and the favorable functional outcome. This study aimed to investigate the existence of this phenomenon in young stroke patients.Methods: We analyzed a total of 9,087 young stroke cases registered in the nationwide stroke registry system of Taiwan between 2006 and 2016. Smoking criteria included having a current history of smoking more than one cigarette per day for more than 6 months. After matching for sex and age, a Cox model was used to compare mortality and function outcomes between smokers and non-smokers.Results: Compared with the non-smoker group, smoking was associated with older age, higher comorbidities, and higher alcohol consumption. Patients who report smoking with National Institutes of Health Stroke Scale scores of 11–15 had a worse functional outcome (adjusted odds ratio, 0.81; 95% confidence interval, 0.76 – 0.87).Conclusion: Smokers had a higher risk of unfavorable functional outcomes at 3 months after stroke, and therefore, we continue to strongly advocate the importance of smoking cessation.
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