Those with the greatest hearing impairment are at the greatest risk of death, according to the researchers.
The findings of a team from John Hopkins University School of Medicine in Baltimore, MD, show that the greater a person's hearing impairment, the greater their risk of death.
The occurrence of hearing impairment (HI) doubles with every decade of life and affects two thirds of adults older than 70.
HI is closely associated with lower levels of wellbeing and quality of life. According to the National Institute on Deafness and other Communication Disorders (NIDCD), it can, for example, make it more difficult to respond to warnings, hear doorbells and smoke alarms.
According to the World Health Organization (WHO), 360 million people around the globe have disabling hearing loss, defined as hearing loss greater than 40 decibels (dB) in the better hearing ear.
The data for this latest study came from 2005-06 and 2009-10 cycles of the National Health and Nutrition Examination Survey (NHANES). The study population was made up of 1,666 adults who had undergone audiometric testing and were 70 years or older.
Probability matching between this data and death certificates from the National Death Index through to the end of December 2011 was used to determine mortality.
Fast facts about hearing impairment
- Approximately 1 in 3 people in the US between the ages of 65-74 have hearing loss
- Almost half of people older than 75 have difficulty hearing
- Hearing loss can be attributed to conditions that are more common in older people, such as high blood pressure or diabetes.
Hearing loss was categorized as mild, moderate, severe or profound.
Up to 54% greater risk of death
In an age-adjusted model, the researchers found participants with moderate or more severe HI had a 54% increased risk of death, while those with mild HI had a 27% increased risk of death, compared with those free of HI.
After adjustments were made for demographic and cardiovascular characteristics, the team found participants with moderate or more severe HI had a 39% increased risk of death, while those with mild HI had a 21% increased risk of death, compared with those without HI.
Even when limiting analysis further to those aged 80 years or younger, the results produced suggested a link between HI and increased death risk.
The potential mechanisms for these findings, the authors say, include causal connections of HI with cognitive, mental and physical function.
Commenting on their findings, the researchers say:
"Future studies are required to explore the basis of the association of HI with mortality and to determine whether therapies to rehabilitate hearing can reduce mortality."
Last year, Medical News Today reported on how hearing loss in older people could be linked to faster brain shrinkage.