MONDAY, Feb. 21 (HealthDay News) -- An estimated 21 percent of Americans aged 48 to 59 struggle with some kind of hearing loss, and the number rises to 90 percent of adults 80 and older, a new study says.

Yet much of that hearing loss may be preventable, the researchers pointed out.

Factors that contribute to hearing loss include working in a noisy environment, having a parent who had hearing loss, and, possibly, heart disease. Hearing loss is associated with difficulty communicating, a poor quality of life, dementia and cognitive problems, the study authors noted.

"Hearing loss may not be an inevitable part of aging, and our findings, which are in line with other studies, point to the possibility that if we live healthier lifestyles, lifestyles that can reduce our chance of cardiovascular disease for example, we may be able to prevent or delay hearing loss," said lead researcher Scott D. Nash, who's with the University of Wisconsin School of Medicine and Public Health in Madison.

Hearing loss is a common problem, Nash said. "In our study, nearly one out of seven adults over the age of 21 had hearing loss. In participants 65 years and older, more than 40 percent had hearing loss. We also found hearing loss was associated with some cardiovascular measures," he added.

"One possible explanation for the connection between cardiovascular disease and hearing loss may be that disruptions or changes to blood flow that come with cardiovascular disease may lead to less oxygen in the inner ear or other parts of the auditory pathway," he speculated.

The new report is published in the Feb. 21 online edition of the Archives of Otolaryngology -- Head & Neck Surgery.

For the study, Nash and his colleagues collected data on 3,285 men and women who were part of the Beaver Dam Offspring Study, which looks at aging and its effects. The average age of the participants was 49.

The researchers measured hearing loss as the ability to hear certain tones, and also as the ability to recognize words at different sound levels and words spoken by male and female voices.

Nash's team found that 14.1 percent of the study participants had some level of hearing loss.

In the word recognition test, 89.6 percent of the people were able to hear the words well when they were spoken in a quiet environment, but only 63.5 percent heard the words correctly when the environment was noisy, such as one might experience in a crowd.

Hearing loss was most common among men and the less educated, and people who worked in a noisy environment or who had had ear surgery.

The researchers noted that heart disease was another factor that seemed to have an effect on hearing, citing the use of cholesterol-lowering drugs, hematocrit level (a measure of blood thickness), and arterial wall thickness.

Also, if a parent suffered hearing loss their children had a significantly higher risk of hearing impairment because hearing loss is a "highly heritable condition," the researchers said.

Commenting on the study, Dr. Thomas Balkany, director of the University of Miami Ear Institute, said that "the world is getting noisier all the time."

Balkany thinks it's this increasing level of noise that is causing the increasing hearing loss, particularly for lower-income people who often are exposed to louder noise over a longer period of time at their jobs.

This is why Balkany thinks the link between such health problems as heart disease, diabetes, smoking, obesity and hearing loss is largely due to social factors, which put people in unhealthy environments where hearing loss is a byproduct. In other words, lifestyles that increase the risk for chronic health problems also increase the risk for hearing loss.

There's not much one can do, added Balkany, who's also chairman of the otolaryngology department at the University of Miami Miller School of Medicine. "The message is the same -- protect your hearing," he said.

More information

For more information on hearing loss, visit the U.S. National Library of Medicine.