According to the World
Health Organization, 360
million people
have disabling hearing loss,
a condition that is often considered to be an
unavoidable side effect of aging. New
research from Brigham and Women's Hospital (BWH) published online in The
American Journal of Medicine,
finds that a higher body mass index (BMI) and larger waist circumference are each
associated with higher risk of hearing loss, while a higher level of physical
activity is associated with lower risk of hearing loss in women.
"We
often think of hearing loss as an inevitable part of the aging process, but
these findings provide evidence that potentially modifiable risk factors, such
as maintaining a healthy weight and staying physically active, may help in the prevention
of hearing loss or delay its progression," said Sharon Curhan, MD, ScM, lead author of the
paper and a researcher in the Channing
Division of Network Medicine at BWH.
Using
data from 68,421 women in the Nurses' Health Study II who were followed
from 1989 to 2009, researchers analyzed information on BMI, waist
circumference, physical activity, and self-reported hearing loss. The baseline and updated information was
obtained through validated biennial questionnaires. Researchers found that women with a BMI of 30-34 had a relative risk for hearing loss
that was 17 percent higher, and with a BMI of 40 or more had a relative
risk that was 25 percent higher, when compared with those with a BMI of less
than 25.
For
women with waist circumference 80-88 cm, the relative risk for hearing loss was
11 percent higher and with waist circumference greater than 88 cm the relative
risk was 27 percent higher when compared with women with waist circumference
less than 71 cm.
Researchers also found that higher level of
physical activity was associated with lower risk. Compared with women who were
the least physically active, women who were the most physically active had a 17
percent lower risk of hearing loss. Walking, which was the most common form of
physical activity reported among these women, was associated with lower risk;
walking 2 hours per week or more was associated with a 15 percent lower risk of
hearing loss, compared with walking less than one hour per week.
This research was funded by grants
DC010811 and CA50385 from the National Institutes of Health and from Vanderbilt
University School of Medicine.
