Smoking and Stroke Risk

Smoking and Stroke Risk

John (Gold)
John (Gold)

May 22nd, 2003, 9:50 pm #1



Smoking and Stroke Risk

(Wednesday, 21st May 2003)
Smoking increases the risk of all forms of stroke (REF: Stroke)
Paper reviewed by Clinnix medical consultant Dr Hugh Bethell.

Cigarette smoking is a well-established risk factor for ischaemic stroke and subarachnoid haemorrhage (SAH) but there is uncertainty about the role of tobacco in intracerebral haemorrhage (ICH). This study shows that smoking does play an important part in the aetiology of ICH.

The study looked at the incidence of, and risk factors for, stroke in the US-based Physicians' Health Study, which included 22,067 apparently healthy male physicians. During 17.8 years of follow-up, involving 385,419 person-years, a total of 1,069 strokes occurred, of which 139 were haemorrhagic (108 ICH, 31 SAH), 913 were ischaemic and 17 were undefined. 49.6% of the cohort reported having never smoked, 39.4% reported past smoking, 3.9% reported current smoking <20 cigarettes/day and 7.1% reported smoking 20 or more/day.

The correlations between smoking and stroke were:
  • Compared with non-smokers, ex-smokers had no increase in risk of haemorrhagic stroke - neither ICH or SAH
  • For smokers of less than 20/day, the relative risk (RR) for haemorrhagic stroke was 1.65 - 1.6 for ICH, and 1.8 for SAH
  • For smokers of 20 or more/day, the RR of haemorrhagic stroke was 2.36 - 2.1 for ICH, and 3.2 for SAH
  • Compared to never-smokers, the RRs for ischaemic stroke were 0.99 for ex-smokers, 1.56 for smokers of less than 20/day and 2.25 for smokers of 20 or more/day.
Haemorrhagic stroke accounts for about 20% of all strokes and the incidence of ICH is about twice that of SAH. ICH has a mortality of 40 to 50% and carries a high prevalence of long-term disability. The results confirm that cigarette smoking is an important risk factor for this dangerous condition, with a graded increase in risk with increasing cigarette intake.

As the authors of this study report, 'The effect of smoking on ICH is of about the same magnitude as the effect of smoking on ischaemic stroke. These results add to the multiple health benefits that can be accrued by abstaining from cigarette smoking.'

REF: Kurth T et al. Smoking and the risk of haemorrhagic stroke in men. Stroke 2003; 34: 1151-5

Last edited by John (Gold) on July 7th, 2009, 3:17 pm, edited 1 time in total.
Quote
Share

John (Gold)
John (Gold)

March 22nd, 2004, 9:35 pm #2

The below study found that a smoker's risk of stroke was 500% greater than a never-smokers risk and that the risk declines dramatically after quitting even for heavy smokers. There was always only one rule ... no nicotine ... Never Take Another Puff!


Active and passive smoking and the risk of subarachnoid hemorrhage: an international population-based case-control study.
Stroke. 2004 March ;35(3):633-7. Epub 2004 Jan 29.

Anderson CS, Feigin V, Bennett D, Lin RB, Hankey G, Jamrozik K; Australasian Cooperative Research on Subarachnoid Hemorrhage Study (ACROSS) Group.

Clinical Trials Research Unit, University of Auckland, Private Bag 92019, Auckland, New Zealand. [url=mailto:c.anderson@ctru.auckland.ac.nz]c.anderson@ctru.auckland.ac.nz[/url]

BACKGROUND AND PURPOSE: This study was undertaken to better clarify the risks associated with cigarette smoking and subarachnoid hemorrhage (SAH).

METHODS: The study included 432 incident cases of SAH frequency matched to 473 community SAH-free controls to determine dose-dependent associations of active and passive smoking (at home) and smoking cessation with SAH.

RESULTS: Compared with never smokers not exposed to passive smoking, the adjusted odds ratio for SAH among current smokers was 5.0 (95% confidence interval [CI], 3.1 to 8.1); for past smokers, 1.2 (95% CI, 0.8 to 2.0); and for passive smokers, 0.9 (95% CI, 0.6 to 1.5). Current and lifetime exposures showed a clear dose-dependent effect, and risks appeared more prominent in women and for aneurysmal SAH. Approximately 1 in 3 cases of SAH could be attributed to current smoking, but risks decline quickly after smoking cessation, even among heavy smokers.

CONCLUSIONS: A strong positive association was found between cigarette smoking and SAH, especially for aneurysmal SAH and women, which is virtually eliminated within a few years of smoking cessation. Large opportunities exist for preventing SAH through smoking avoidance and cessation programs.

PMID: 14752125 [PubMed - in process]
Last edited by John (Gold) on July 7th, 2009, 3:16 pm, edited 1 time in total.
Quote
Share

Joined: November 11th, 2008, 7:22 pm

July 21st, 2010, 12:55 pm #3

A frightening new analysis of smoking and risk of suffering a stroke concludes that the more the smoker smokes the greater their risk of stroke.   How much greater?   This is a quote from the full text of the study.  OR stands for odds ratio.









Smoking and stroke:
the more you smoke the more you stroke.
Expert Review of Cardiovascular Therapy, 2010 Jul;8(7):917-32.

Shah RS, Cole JW.

Department of Neurology, University of Maryland School of Medicine, 110 South Paca Street, Third Floor, Baltimore, MD 21201-1559, USA.

Abstract

Cigarette smoking is a well-established risk factor for all forms of stroke. While both the general public and the global healthcare system are aware of the vascular risks associated with smoking, the prevalence of tobacco use has remained largely unchanged over the last quarter of a century. Approximately one in five US adults are classified as regular smokers, with the initiation of smoking typically occurring during the teenage years. Although the increased risk of stroke associated with smoking is generally acknowledged, it is less well recognized that considerable scientific evidence implicates a strong dose-response relationship between smoking and stroke risk. In this article, we summarize the literature regarding smoking-related stroke risk, the dose-response relationship, and the costs of this detrimental habit to both the individual and society as a whole.

PMID: 20602553

PubMed Source Link: http://www.ncbi.nlm.nih.gov/pubmed/20602553
Quote
Like
Share