Association Between Changes in Smoking Habits and Incident Fracture After Acute Ischemic Stroke

Abstract

Background Survivors of stroke, particularly the older population, are at an increased risk of falls and incident fractures. Smoking is a widely recognized risk factor for fractures. However, the association between changes in smoking habits before and after an index stroke and increased risk of fracture remains unelucidated. Methods and Results Using the Korean National Health Insurance program, patients with ischemic stroke between 2010 and 2016 were enrolled. Individuals were classified by smoking habits: “never smoker,” “former smoker,” “smoking quitter,” “new smoker,” and “sustained smoker.” The primary outcome was the composite outcome of the vertebral, hip, and any fractures. Multivariable Cox proportional hazards regression analysis was conducted, using the never‐smoker group as the reference. Among 177 787 patients with health screening data within 2 years before and after ischemic stroke, 14 991 (8.43%) patients had any fractures. After multivariable adjustment, the sustained smokers had a significantly increased risk of composite primary outcomes of any, vertebral, and hip fractures (adjusted HR [aHR], 1.222 [95% CI, 1.124–1.329]; aHR, 1.27 [95% CI, 1.13–1.428]; aHR, 1.502 [95% CI, 1.218–1.853], respectively). Additionally, the new smoker group exhibited a similar or higher risk of any fractures and hip fractures (aHR, 1.218 [95% CI, 1.062–1.397]; aHR, 1.772 [95% CI, 1.291–2.431], respectively). Conclusions Sustained smokers had a significantly increased risk of vertebral and hip fractures after an ischemic stroke. The risk of any hip fractures was higher in new smokers after ischemic stroke. As poststroke fractures are detrimental to the rehabilitation process of patients with stroke, physicians should actively advise patients to stop smoking.