Number of Cigarettes Smoked Per Day, Smoking Index, and Intracranial Aneurysm Rupture: A Case-Control Study.

Xin Feng,Zhongxue Wu,Xiaolong Wen,Luyao Wang,Zenghui Qian,Wenjuan Xu,Chuhan Jiang,Baorui Zhang,Aihua Liu,Erkang Guo,Youxiang Li,Peng Liu

doi:10.3389/fneur.2018.00380

Abstract

We aimed to investigate the effect of smoking on the risk of intracranial aneurysm (IA) rupture (IAR), specifically relationship between the number of cigarettes smoked per day (CPD) or smoking index and the risk of IAR. We performed a single-center case-control study of consecutive patients evaluated or treated for IA at our institution from June 2015 to July 2016. Cases were patients with a ruptured IA. Two age- and sex-matched controls with an unruptured IA were included per case. Conditional logistic regression models were used to assess the relationship between both the CPD and smoking index (CPD × years of smoking) and IAR. The study population included 127 cases of IAR and 254 controls. The higher IAR risk was associated with cigarette smoking (both current and former) (OR, 2.3; 95% CI, 1.1-4.8; P = 0.029). Our subgroup analysis of smokers revealed a significant association between IAR risk and current smoking (OR, 2.8; 95% CI, 1.2-6.3; P = 0.012), current heavy smoking (CPD ≥ 20) (OR, 3.9; 95% CI, 1.4-11.0; P = 0.007), and a smoking index ≥800 (OR, 11.4; 95% CI, 2.3-24.5; P = 0.003). Former smoking was not significantly associated with IAR (OR, 1.1; 95% CI, 0.3-4.0; P = 0.929). A dose-response relationship has been noted for intensity and duration of smoking consumption and increased risk of IAR. As smoking is modifiable, this finding is important to managing patients with IAs to quit or reduce smoking prior to life-threatening subarachnoid hemorrhage.

Highlights

3% of the adult population was found to have an unruptured intracranial aneurysm (IA) [1]
Our exclusion criteria included: [1] dissecting, fusiform, traumatic, mycotic, or partially thrombosed aneurysms; [2] the patients with nonaneurysmal subarachnoid hemorrhage (SAH) examinated by digital subtraction angiography (DSA), or the location of ruptured aneurysm could not be identified among multiple IAs by computed tomography (CT) and DSA; [3] aneurysms without clear and readable three-dimensional rotational angiography that allowed an evaluation of lesion geometry and morphology; [4] aneurysms associated with cerebral arteriovenous malformation, arteriovenous fistula, or moyamoya disease
Cases and controls showed significant differences in frequency and risk of intracranial aneurysm rupture (IAR) based on smoking status determined by cigarettes smoked per day (CPD) [nonsmoker, former smoker, mild current smoking (CPD

Summary

Introduction

3% of the adult population was found to have an unruptured intracranial aneurysm (IA) [1]. To prevent SAH via modifiable risk factors identification and management, rather than surgical clipping and intravascular intervention, is of great clinical and social value. Smoking is the most important established risk factor for IA rupture [3,4,5,6], and up to 80% of patients who sustain an aneurysmal SAH have a history of smoking, and 50–60% are current smokers [7, 8]. A Finnish register-based study reported that the incidence of SAH was decreasing and this trend may be associated with changes in smoking rates, suggesting the possible benefits of smoking cessation [9]. We aimed to investigate the effect of smoking on the risk of intracranial aneurysm (IA) rupture (IAR), relationship between the number of cigarettes smoked per day (CPD) or smoking index and the risk of IAR

Objectives

Methods

Results

Conclusion