social isolation

With age comes hearing loss and a greater risk of cognitive decline

But study suggests higher education might counter effects of milder hearing impairment

February 12, 2019

Science Daily/University of California - San Diego

In a new study, researchers report that hearing impairment is associated with accelerated cognitive decline with age, though the impact of mild hearing loss may be lessened by higher education


Hearing impairment is a common consequence of advancing age. Almost three-quarters of U.S. adults age 70 and older suffer from some degree of hearing loss. One unanswered question has been to what degree hearing impairment intersects with and influences age-related cognitive decline.


In a new study, researchers at University of California San Diego School of Medicine report that hearing impairment is associated with accelerated cognitive decline with age, though the impact of mild hearing loss may be lessened by higher education.


The findings are published in the February 12, 2019 issue of the Journal of Gerontology: Series A Medical Sciences.


A team of scientists, led by senior author Linda K. McEvoy, PhD, professor in the departments of Radiology and Family Medicine and Public Health, tracked 1,164 participants (mean age 73.5 years, 64 percent women) in the longitudinal Rancho Bernardo Study of Healthy Aging for up to 24 years. All had undergone assessments for hearing acuity and cognitive function between the years 1992 to 1996 and had up to five subsequent cognitive assessments at approximately four-year intervals. None used a hearing aid.


The researchers found that almost half of the participants had mild hearing impairment, with 16.8 percent suffering moderate-to-severe hearing loss. Those with more serious hearing impairment showed worse performance at the initial visit on a pair of commonly used cognitive assessment tests: the Mini-Mental State Exam (MMSE) and the Trail-Making Test, Part B. Hearing impairment was associated with greater decline in performance on these tests over time, both for those with mild hearing impairment and those with more severe hearing impairment.


However, the association of mild hearing impairment with rate of cognitive decline was modified by education. Mild hearing impairment was associated with steeper decline among study participants without a college education, but not among those with higher education. Moderate-to-severe hearing impairment was associated with steeper MMSE decline regardless of education level.


"We surmise that higher education may provide sufficient cognitive reserve to counter the effects of mild hearing loss, but not enough to overcome effects of more severe hearing impairment," said McEvoy.


Degree of social engagement did not affect the association of hearing impairment with cognitive decline. "This was a somewhat unexpected finding" said first author Ali Alattar. "Others have postulated that cognitive deficits related to hearing impairment may arise from social isolation, but in our study, participants who had hearing impairment were as socially engaged as those without hearing loss."


The findings, said the authors, emphasize the need for physicians to be aware that older patients with hearing impairments are at greater risk for cognitive decline. They also emphasized the importance of preventing hearing loss at all ages, since hearing impairment is rarely reversible. One important way to protect hearing, they said, is to minimize loud noise exposure since this is the largest modifiable risk factor for hearing impairment.


Known risk factors largely explain links between loneliness and first time heart disease/stroke

But social isolation still associated with death among those with preexisting cardiovascular disease

March 26, 2018

Science Daily/BMJ

Conventional risk factors largely explain the links observed between loneliness/social isolation and first time heart disease/stroke, a new study finds. But having few social contacts still remains an independent risk factor for death among those with pre-existing cardiovascular disease.


Recent research has increasingly highlighted links between loneliness and social isolation and cardiovascular disease and death. But most of these studies have not considered a wide range of other potentially influential factors, say the authors.


In a bid to clarify what role these other factors might have, they drew on data from nearly 480,000 people aged between 40 and 69, who were all part of the UK Biobank study between 2007 and 2010.


Participants provided detailed information on their ethnic background, educational attainment, household income, lifestyle (smoking, drinking, exercise) and depressive symptoms.


They were also asked a series of questions to gauge their levels of social isolation and loneliness. Height, weight, and grip strength were measured, and blood samples taken.


Their health was then tracked for an average of 7 years.


Nearly one in 10 (9%) respondents were deemed to be socially isolated, 6 percent lonely, and 1 percent both.


Those who were socially isolated and/or lonely were more likely to have other underlying long term conditions and to be smokers, while those who were lonely reported more depressive symptoms.


During the 7 year monitoring period, 12,478 people died. And 5731 people had a first time heart attack while 3471 had a first time stroke.


Social isolation was associated with a 43 percent higher risk of first time heart attack, when age, sex, and ethnicity were factored in.


But when behavioural, psychological, health, and socioeconomic factors were added into the mix, these factors accounted for most (84%) of the increased risk, and the initial association was no longer significant.


Similarly, social isolation was initially associated with a 39 percent heightened risk of a first time stroke, but the other conventional risk factors accounted for 83 percent of this risk.


Similar results were observed for loneliness and risk of first time heart attack or stroke.


But this was not the case for those with pre-existing cardiovascular disease among whom social isolation was initially associated with a 50 percent heightened risk of death. Although this halved when all the other known factors were considered, it was still 25 percent higher.


Similarly, social isolation was associated with a 32 percent heightened risk of death even after all the other conventional factors had been accounted for.


This is an observational study so no firm conclusions can be drawn about cause and effect, but the findings echo those of other research in the field, say the study authors.


And the size and representative nature of the study prompt the authors to conclude that their findings "indicate that social isolation, similarly to other risk factors such as depression, can be regarded as a risk factor for poor prognosis of individuals with cardiovascular disease."


This is important, they emphasise, as around a quarter of all strokes are recurrent, and targeting treatment of conventional risk factors among the lonely and isolated might help stave off further heart attacks and strokes, they suggest.

Member Login
Welcome, (First Name)!

Forgot? Show
Log In
Enter Member Area
My Profile Not a member? Sign up. Log Out