Passive smoking exposure nearly doubles stroke risk, new study says

In a recent study published in eClinicalMedicine, researchers delved into the intricate relationship between smoking habits and the likelihood of experiencing a stroke. This comprehensive investigation shed light on how various aspects of smoking behavior influenced the risk of stroke occurrence.

The study revealed that individuals who were current smokers faced a significantly elevated risk of suffering from a stroke compared to those who had never smoked. This risk was particularly pronounced for ischaemic strokes, which occurred when blood flow to the brain was obstructed. Collaborating on this international study were researchers from St John's Medical College and Research Institute in Bengaluru.

Impact of different smoking habits

Both filtered and non-filtered cigarette consumption were found to be associated with increased stroke risk. Additionally, exposure to environmental tobacco smoke (ETS) for more than 10 hours per week was identified as a significant risk factor, nearly doubling the likelihood of experiencing a stroke, particularly ischaemic and intracerebral haemorrhage (ICH) strokes, which resulted from bleeding within the brain due to a ruptured blood vessel.

The study highlighted that among individuals under 50 years of age who smoked heavily (more than 20 cigarettes per day), the risk of stroke more than doubled, surpassing the increase observed in participants aged 70 and above. Furthermore, for those aged 50-59, there was an eightfold increase in the risk of large vessel stroke, affecting major blood vessels supplying the brain.

Analysis of data from 32 countries across various income levels revealed regional disparities in stroke risk among current smokers. Western European and North American regions exhibited the highest risk. Interestingly, regardless of income level, the risk was higher in high-income countries (HICs) compared to low- and middle-income countries (LMICs), with younger smokers facing a heightened risk compared to older individuals. Moreover, the risk escalated with the number of cigarettes smoked per day, particularly in HICs.

The findings of this study shed light on the importance of global initiatives aimed at curbing tobacco use and exposure. To mitigate stroke risk associated with smoking, the researchers advocated for preventive measures targeting youth initiation prevention and smoking cessation support for current smokers. Additionally, legislative actions to establish and promote smoke-free environments were recommended.

Notable regional disparities in smoking prevalence were observed, with around 46 per centof young men in South East Asia reported as current smokers, while over 16 per centof young females in Eastern/Central Europe and the Middle East were identified as current smokers.

(With inputs from agencies)