This article requires a subscription to view the full text. If you have a subscription you may use the login form below to view the article. Access to this article can also be purchased.
Abstract
Objective: Smoking and family history of aneurysmal subarachnoid hemorrhage (aSAH) are independent risk factors for aSAH. Using a population-based case-control study of hemorrhagic stroke, we hypothesized that having both a first-degree relative with a brain aneurysm or SAH (+FH) and current smoking interact to increase the risk of aSAH.
Methods: Cases of aneurysmal SAH were prospectively recruited from all 17 hospitals in the five-county region around the University of Cincinnati. Controls were identified by random digit dialing. Controls were matched to cases of aSAH by age (±5 years), race, and sex. Conditional multiple logistic regression was used to identify independent risk factors. For deviation from the additive model, the interaction constant ratio test was used.
Results: A total of 339 cases of aSAH were matched to 1,016 controls. Compared to current nonsmokers with no first-degree relatives with aSAH (−FH), the odds ratio (OR) for aSAH for current nonsmokers with +FH was 2.5 (95% confidence interval [CI] 0.9–6.9); for current smokers with −FH, OR = 3.1 (95% CI 2.2–4.4); and for current smokers with +FH, OR = 6.4 (95% CI 3.1–13. 2). The interaction constant ratio, which measured the deviation from the additive model, was significant: 2.19 (95% CI 0.80–5.99). The lower bound of the 95% CI >0.5 signifies a departure from the additive model.
Conclusion: Evidence of a gene–environment interaction with smoking exists for aneurysmal subarachnoid hemorrhage. This finding is important to counseling family members and for screening of intracranial aneurysm (IA) as well as the design and interpretation of genetic epidemiology of IA studies.
Glossary
- aSAH=
- aneurysmal subarachnoid hemorrhage;
- CI=
- confidence interval;
- GERFHS=
- Genetic and Environmental Risk Factors of Hemorrhagic Stroke;
- IA=
- intracranial aneurysm;
- ICH=
- intracerebral hemorrhage;
- ICR=
- interaction contrast ratio;
- OR=
- odds ratio.
AAN Members
We have changed the login procedure to improve access between AAN.com and the Neurology journals. If you are experiencing issues, please log out of AAN.com and clear history and cookies. (For instructions by browser, please click the instruction pages below). After clearing, choose preferred Journal and select login for AAN Members. You will be redirected to a login page where you can log in with your AAN ID number and password. When you are returned to the Journal, your name should appear at the top right of the page.
AAN Non-Member Subscribers
Purchase access
Letters: Rapid online correspondence
REQUIREMENTS
If you are uploading a letter concerning an article:
You must have updated your disclosures within six months: http://submit.neurology.org
Your co-authors must send a completed Publishing Agreement Form to Neurology Staff (not necessary for the lead/corresponding author as the form below will suffice) before you upload your comment.
If you are responding to a comment that was written about an article you originally authored:
You (and co-authors) do not need to fill out forms or check disclosures as author forms are still valid
and apply to letter.
Submission specifications:
- Submissions must be < 200 words with < 5 references. Reference 1 must be the article on which you are commenting.
- Submissions should not have more than 5 authors. (Exception: original author replies can include all original authors of the article)
- Submit only on articles published within 6 months of issue date.
- Do not be redundant. Read any comments already posted on the article prior to submission.
- Submitted comments are subject to editing and editor review prior to posting.
You May Also be Interested in
Dr. Jessica Ailani and Dr. Zubair Ahmed