By LOIS BAKER
Contributing Editor
Young African Americans who use cocaine are six times more likely to
suffer a potentially lethal episode of bleeding inside the brain than
non-users, a case-control study of major risk factors for intracerebral
hemorrhage in this population conducted by researchers at UB and Emory
University has found.
The study, published in a recent issue of Ethnicity and Disease, also
shows twice the incidence of hypertension and five times the number
of people with hypertension who weren't taking their blood-pressure
medicine among those who had had an intracerebral hemorrhage compared
to healthy, age-matched controls. Alcohol use also was associated with
an increase in risk.
"African-American patients experience a two-fold higher risk of intracerebral
hemorrhage compared to white patients," said Adnan I. Qureshi, UB assistant
professor of neurosurgery and lead author on the study.
"In the absence of any definitive treatment for intracerebral hemorrhage,
significant stress needs to be placed on primary prevention and understanding
of factors that predispose to a higher risk in young African Americans,"
he said.
Internal bleeding, also known as intracerebral hemorrhage (ICH), occurs
in about 20 out of 100,000 people, statistics show, and can affect any
person regardless of age, sex or race, but appears to occur more frequently
in African Americans. The incidence of intracerebral hemorrhage in African
Americans reaches nearly 50 out of 100,000 persons, Qureshi noted.
Since there is no effective treatment for ICH, prevention takes center
stage, but little information has been available on the factors that
put this population at higher risk. This study is the first to use a
case-control approach to tease out these risks. It assessed health and
lifestyle histories of 122 African Americans between the ages of 18
and 45 admitted to a public hospital in Atlanta with ICH between Dec.
31, 1997, and Jan. 1, 1990. This data was compared with that from 366
African Americans in the same age group without the condition who took
part in the most recent National Health and Nutrition Examination Survey
(NHANES III).
Researchers included data on hypertension, diabetes, smoking, cocaine
use, alcohol use and stroke or heart disease from all participants,
as well as the record of prescriptions for hypertension medication and
compliance with their use.
Results showed that cocaine use was the strongest risk factor associated
with ICH in this population, even higher than hypertension, Qureshi
said. "While the mechanism for this association isn't clear, we suspect
that the sudden elevation in blood pressure that occurs immediately
after using cocaine may cause an existing aneurysm or arteriovenous
malformation (AVM) in the brain to rupture."
Hypertension, particularly in those who had been prescribed medication
but took it irregularly, also was shown to be an important high-risk
factor for ICH.
"In chronic hypertension, the body develops a certain protective response
in an effort to counter high blood pressure's effects," he said. Taking
blood-pressure medication intermittently may impair the development
of this response and may make patients more vulnerable to blood pressure
fluctuations."
The bottom line, Qureshi said, is that a reduction in the high rate
of death and disability associated with intracerebral hemorrhage can't
occur without effective preventive measures.
"The study demonstrated the presence of factors in the community that
easily can be modified to reduce this risk. These include avoidance
of cocaine use and regular use of blood pressure medication as prescribed."