Posted
11/4/2008
USC researchers to tie into existing major study based
at University of Alabama at Birmingham
Public health researchers in South Carolina and Alabama are joining
forces to study the effects of physical activity on stroke and cognitive
decline in a group of some 20,000 racially and geographically diverse
men and women.
|
Steven
Hooker |
Dr. Steven P. Hooker, director of the USC Prevention Research Center and
research associate professor in the Arnold School’s Department of
Exercise Science, will lead the five-year $2.9 million study.
Hooker’s effort is an ancillary study to the Reasons for Geographic and
Racial Differences in Stroke (REGARDS) – study, based at the University
of Alabama at Birmingham.
REGARDS, which has enrolled more that 30,000 persons, aims to determine
why the “stroke belt” — comprised of the Carolinas, Georgia, Tennessee,
Alabama, Mississippi, Arkansas and Louisiana — has a stroke death rate
one-and-a-half times the national average. African-Americans are
particularly vulnerable with a stroke rate almost double that of
Caucasians.
Hooker’s study is funded by the National Institute of Neurological
Disorders and Stroke. Entitled REGARDS-PA, it will examine the
relationship between objectively measured physical activity and risks of
stroke and cognitive decline.
Studies on the relationship of physical activity to stroke and cognitive
decline have been done before, says Hooker. However, those studies,
which used self-reported information, left a wide margin for error. In
addition, no other study on physical activity and stroke or cognitive
function has as large a population of African Americans as does
REGARDS-PA.
“The difference with REGARDS-PA is that for the first time, we’ll be
using an objective measurement of physical activity which is much more
accurate and yields more detailed information about a person’s physical
activity patterns,” he said.
REGARDS-PA participants will wear a data collection device called an
accelerometer, a small electromechanical instrument about the size of a
quarter.
Attached to a belt around the waist, the waterproof, shockproof
accelerometer measures a person’s movement across a wide range of
activities – from sitting to vacuuming to walking.
The study calls for a participant to wear the device for a week, then
mail it to REGARDS headquarters in Birmingham. Downloaded to a computer,
the data can chart the full range of a person’s physical activity
including frequency, intensity and duration.
“This knowledge will have important clinical and public health
implications. We expect to enhance health-related physical activity
recommendations and improve stroke prevention,” Hooker said in his
application for the study.
The accelerometer data is expected to show with some precision the
degree to which physical activity influences stroke and cognitive
decline – “a dose-response relationship,” as Hooker describes it. “We
will also be able to look at these relationships specifically for men,
women, whites, African Americans, and persons living in various
geographic regions,” he said.
Particularly interesting, he said, is testing the idea that even small
amounts of physical activity can influence brain health and prevent
stroke in mid-life and older adults.
Hooker said that the parent REGARDS study, which was renewed recently
with a $20.8 million grant, is a cornucopia for stroke and brain health
researchers. Participants in the study are made up of about one-half men
and women, and the same proportion of whites and African-Americans. All
of the participants are 45 years of age or older.
The parent REGARDS study already has a research infrastructure in place
and Hooker will make use of its staff to help recruit participants,
distribute the accelerometers, and assemble the data.
Hooker’s study also will have the support of Dr. Steven Blair of the
Department of Exercise Science, Dr. Natalie Colabianchi of the
Department of Epidemiology and Biostatistics, and Brent Hutto of the
Prevention Research Center.
Two former Arnold School faculty members are also members of the
REGARDS-PA research team. They are Dr. John Vena, now chair of the
Department of Epidemiology and Biostatistics at the University of
Georgia and Dr. Jim Laditka, associate professor of Public Health
Sciences at the University of North Carolina at Charlotte.
REGARDS-PA is being funded by Hooker’s first NIH RO1 grant, an
acknowledgment of his scholarship and a milestone in his career at USC.
He earned his bachelor’s degree in physical education from California
State University-Fresno in 1978, his master’s in physical education from
California State University-Sacramento in 1984 and his doctorate in
exercise science from Arizona State University in 1988.
|