Study reveals ethnic
differences in heart disease risk factors among youth
BY MITCH LESLIE
Heart disease is not
colorblind. Not only are middle-aged African-Americans
twice as likely to die from heart disease as middle-aged
whites, but both African-Americans and Mexican Americans
are more likely to be overweight and to have other risk
factors that promote cardiovascular disease, such as
high-blood pressure, physical inactivity and diabetes.
A new Stanford study of
more than 7,600 children and young adults shows that
ethnic differences in cardiovascular disease risk factors
are apparent in grade-school children and persist into
adulthood. What's more, the researchers found that ethnic
inequalities remain even when differences in
socioeconomic status are factored out.
"Our results
highlight the need to start interventions for healthy
lifestyles at early ages," said Marilyn Winkleby,
PhD, a senior research scientist at the Stanford Center
for Research in Disease Prevention and the lead
researcher on the study. "Interventions should begin
as early as kindergarten."
Winkleby and colleagues
based their analysis on the Third National Health and
Nutrition Examination Survey, a six-year assessment of
the health and nutritional status of the U.S. population
conducted by the National Center for Health Statistics.
Using questionnaires and medical examinations, this study
gathered data on the health, diet, demography and
economic status of a representative sample of nearly
34,000 Americans.
From this database,
Winkleby's group statistically analyzed information for
2,769 African-Americans, 2,854 Mexican Americans, and
2,063 whites between the ages of 6 and 24. They compared
the prevalence of primary risk factors for cardiovascular
disease among the three ethnic groups. Since the three
groups also differed in average socioeconomic status, the
researchers factored out this variable, using educational
level of the head of household and family income as an
indicator of socioeconomic status.
Winkleby's colleagues were
Tom Robinson, MD, assistant professor of pediatrics; Jan
Sundquist, PhD, a visiting scholar from Sweden; and
Helena Kraemer, PhD, professor of psychiatry and
behavioral sciences. They reported their results in the
March 17 issue of Journal of the American Medical
Association.
Differences in risk
factors were apparent even in the youngest age group: 6
to 9 years. Black and Mexican American girls of that age
were already heavier than their white counterparts, and
this gap continued to grow throughout childhood and
adolescence. In the 18 to 24-year age group, black and
Mexican American women of average height (5 feet 4
inches) were 12 pounds heavier than white women of the
same stature.
Black and Mexican American
girls also get a higher percentage of their energy from
fat than do white girls and are at higher risk of
diabetes. Black girls also have higher blood pressure
than white girls.
The picture was slightly
different for boys. Black and Mexican American boys were
at higher risk for diabetes, and black boys ate a fattier
diet than white boys, but there were no significant
differences in weight or blood pressure.
One sobering fact was the
high rate of smoking among young white men and women,
especially those with lower socioeconomic status. In the
lowest socioeconomic group (head of household with fewer
than 12 years of education), 77 percent of young white
men and 61 percent of young white women were current
smokers.
Although the differences
between ethnic groups may have some genetic basis,
focusing only on genetic causes would be a mistake,
Winkleby noted. Some of the causes of heart disease may
yet be unknown, she said. Cardiovascular disease, which
can build for decades before manifesting as a heart
attack or stroke, is an insidious collaboration between
genes and lifestyle. The genes that increase the risk of
cardiovascular disease will not be expressed without the
right environmental conditions an unhealthy lifestyle.
"We don't have methods to change genes, but we do
know how to change lifestyles. And we know how to promote
and maintain healthy behaviors," Winkleby said.
She and her coauthors
recommend ethnically diverse educational programs to
teach the importance of heart-healthy behaviors.
The research was funded by
grants from the American Heart Association, the U.S.
Public Health Service and the Swedish Research Council.
SR
|
