Obesity may increase the risk of hearing loss in women, while exercising may lower it, a new study has claimed.
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, scientists have found.
"We often think of hearing loss as an inevitable part of the ageing 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, lead author of the study paper.
Using data from 68,421 women who were followed from 1989 to 2009, researchers from Brigham and Women's Hospital (BWH) analysed 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 per cent higher, and with a BMI of 40 or more had a relative risk that was 25 per cent 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 per cent higher and with waist circumference greater than 88 cm the relative risk was 27 per cent 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 per cent 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 two hours per week or more was associated with a 15 per cent lower risk of hearing loss, compared with walking less than one hour per week.
According to the World Health Organisation, 360 million people have disabling hearing loss, a condition that is often considered to be an unavoidable side effect of ageing, researchers said.
The study was published in The American Journal of Medicine.