Medical Xpress – A multi‑institution research team reports that nearly one in three new dementia cases in older adults is associated with hearing loss, based on statistical modeling of population data.
Dementia prevalence is expected to triple globally in the coming decades. Efforts to reduce its burden have increasingly focused on modifiable risk factors. Hearing loss, affecting more than two-thirds of older adults in the United States, has emerged as a potential correlating condition.
Previous estimates of dementia associated with hearing loss in the United States have ranged from 2% to 19%. Variability across studies has been attributed in part to differences in how hearing loss is measured. Many studies use self-reported hearing loss, which tends to underestimate clinically significant impairment in older adults. Whether dementia risk can be reduced by treating hearing loss remains unclear.
Researchers performed a study to calculate the fraction of incident dementia associated with hearing loss in older adults and to investigate differences by age, sex, race, and method of hearing loss measurement.
Data from 2,946 adults aged 66 to 90 years without dementia at baseline were analyzed.
Hearing loss was measured both objectively using pure tone audiometry and subjectively via self-report. Dementia diagnosis was determined using a standardized algorithm incorporating neuropsychological testing, informant interviews, and medical records.
Clinically significant hearing loss measured by audiometry was present in 66.1% of participants. During the follow-up period, 9.9% of participants with hearing loss developed dementia, compared to 4.7% of those with normal hearing.
Among participants aged 75 and older, the model indicates that up to about 31% of dementia cases may be linked to hearing loss. The 95% confidence range runs from -6 to 53%, indicating that the true figure could be far lower or even nonexistent.
