| 
Alcohol Consumption as a Risk
Factor for Stroke
- Heavy alcohol consumption may increase risk of stroke
by a number of mechanisms.
- The reported effects of alcohol consumption on risk of
ischemic stroke have been inconsistent.
- A differential effect of alcohol consumption on stroke
risk in men compared to women has been observed.
Cigarette smoking and heavy drinking often
go hand-in-hand and may cause increases in blood hematocrit
and viscosity. In addition, cardiac rhythm disturbances,
including atrial fibrillation, have been observed wit heavy
alcohol use. Light and moderate alcohol use, on the
other hand, tend to raise levels of high-density-lipoprotein
(HDL) -- the "good" lipoprotein [Wolf PA, et al.
In: Barnett HJM, et al (eds). Stroke. Pathophysiology, Diagnosis
and Management. New York, Churchill Livingstone, 1992].
A number of studies have suggested that heavy
alcohol use, either habitual daily heavy drinking or binge
drinking, is related to an increased incidence of stroke as
a cause of death [Wolf PA, et al, 1992]. Light or moderate
alcohol consumption, however, has been related to a reduced
risk of coronary heart disease.
Some studies have suggested a positive, dose-related
effect of alcohol consumption on risk of intracranial hemorrhage,
both arachnoid and intracerebral [Donahue RP, et al. JAMA.
1986;255:2311. Klatsy AL, et al. Stroke. 1989;20:741].
The reported effects of alcohol consumption on risk of ischemic
stroke have been inconsistent. Some studies have indicated
no significant relationship to thromboembolic stroke [Donahue
RP, et al, 1986]; the Framingham Study data pointed to an
increased incidence of atherothrombotic stroke with increased
levels of alcohol use but only in men [Wolf PA, et al, 1992];
and Klatsy et al suggested a lower incidence of "occlusive
stroke" hospitalizations among heavy drinkers, but this
was not statistically significant.
More recently, a case-controlled study from
Italy compared 200 consecutive ischemic and hemorrhagic stroke
patients and 372 age- and sex-matched control subjects (170
hospital-based and 202 community-based individuals) [Beghi
E, et al. Stroke. 1995;26:1691]. When hospital control
subjects were used as a reference, the relative risk of stroke
was determined to be 2.3 in moderate drinkers and 2.9 in heavy
drinkers (>60 g/day in men and >40 g/day in women).
When community-based controls were used, the relative risks
were 1.4 and 3.0, respectively. The risk did not change
significantly after subgroup analysis (i.e. no difference
between ischemic and hemorrhagic stroke). An amount
of 60 g is equivalent to approximately 2 oz of pure alcohol
(about 3 drinks of hard liquor).
A cohort study from Scandinavia of 15,077 middle-aged
and older men and women found an elevated relative risk of
ischemic stroke mortality (compared with lifelong abstainers)
in men who drank only a few times a year or less (relative
risk 2.0, Cl 1.3-3.2), in men who were often or sometimes
intoxicated (relative risk 1.8, Cl 1.1-2.8), and in men who
reported binge drinking a few times a year or less (relative
risk 1.6, Cl 1.1-2.5) [Hasagi H, et al. Stroke. 1995;26:1768].
Among women, only ex-drinkers had an elevated relative risk
of dying of ischemic stroke (relative risk 3.3, Cl 1.5-7.1).
The risk was reduced for women who had an estimated average
consumption of 0-5 g pure alcohol per day (relative risk 0.6,
Cl 0.5-0.8), for those who did not drink every day (relative
risk 0.7, Cl 0.5-0.6), and for those who never went on a binge
or became intoxicated (relative risk 0.6 and 0.7 respectively,
Cl 0.5-0.8 and Cl 0.5-0.9). No associations were found
between drinking patterns and risk of hemorrhagic stroke.
The findings of this study appear to be consistent with the
Framingham Study data suggesting a differential effect of
alcohol consumption on stroke risk in men compared to women.
The investigators emphasized the importance of distinguishing
between total alcohol abstainers and ex-drinkers because,
in this study, female ex-drinkers were found to have increased
mortality due to ischemic stroke.
|
Stroke Education
