Even Light Smoking Elevates Risk of Brain Bleeding From Intracranial Aneurysm

MedicalResearch.com Interview with:
Joni Valdemar Lindbohm, MD
Department of Public Health
University of Helsinki, Finland

MedicalResearch.com: What is the background for this study?

Response: Approximately 1-6% percent of people carry an unruptured intracranial aneurysm but most of these never rupture during lifetime and cause subarachnoid hemorrhage (SAH). In SAH, the rupture of an aneurysm causes bleeding into the lining between the brain’s surface and underlying tissue. Despite advances in operative techniques, SAH can lead to death in up to 45% of the cases. Because life style risk factors are critical in development of subarachnoid hemorrhage, it is important to characterize the risk factor profile of those with an elevated risk.

Widely accepted risk factors for SAH are increasing age, smoking, hypertension and female sex. However, the reasons for an elevated risk in women have remained uncovered and the effect of smoking habits are not well understood.

MedicalResearch.com: What are the main findings?

Response: We found that smoking elevated subarachnoid hemorrhage risk dose-dependently, even light smoking elevated the risk. However, we also found that after smoking cessation the risk decreases considerably. We also observed that vulnerability to smoking explains the elevated risk of SAH in women. This means that female heavy smokers have considerably higher risk for SAH than men who smoke equal number of cigarettes per day. This effect modification between female sex and smoking explains why previous studies have found female sex to be an independent SAH risk factor. However, smoking is the most important risk factor for subarachnoid hemorrhage in both sexes.

MedicalResearch.com: What should readers take away from your report?

Response: The important finding is that people can greatly lower their risk of subarachnoid hemorrhage – the most severe type of stroke – by not smoking. There is no safe level of smoking and naturally the best option is never to start. The message for health care professionals and politicians is that by implementing effective strategies against smoking they can considerably reduce the burden of SAH.

MedicalResearch.com: What recommendations do you have for future research as a result of this study?

Response: Female heavy smokers with unruptured intracranial aneurysms are high-risk population, whose aneurysms should be treated. An unanswered question is what kind of treatment should be used: options range from medication to supporting smoking cessation and treatment of hypertension, to operative neurosurgical or endovascular treatment.

MedicalResearch.com: Is there anything else you would like to add?

Response: Previously subarachnoid hemorrhages were thought to arise due to genetics but recently we have shown that lifestyle risk factors play the main role in developing subarachnoid hemorrhage. In future more tailored risk assessment strategies based on lifestyle risk factors should be studied in order to prevent subarachnoid hemorrhage.

MedicalResearch.com: Thank you for your contribution to the MedicalResearch.com community.


Sex, Smoking, and Risk for Subarachnoid Hemorrhage

Joni Valdemar Lindbohm, Jaakko Kaprio, Pekka Jousilahti, Veikko Salomaa,and Miikka Korja

Stroke. 2016;STROKEAHA.116.012957published online before print July 21 2016, doi:10.1161/STROKEAHA.116.012957Note: Content is Not intended as medical advice.


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