Hearing Loss, Fatigue, and Cognitive Well-Being: A Closer Look at the Latest Research

Hello, everyone,

and welcome to this Week

in Hearing. These days,

whenever Johns Hopkins

is mentioned,

people immediately think of the

ACHIEVE study and its

recent update.

But the Cochlear Center for

Hearing and Public Health,

led by Dr. Frank Lin,

has been conducting other

interesting research on

comorbidities with hearing loss.

One of these,

exploring a relationship between

hearing loss and fatigue,

especially caught my eye since

it fit with my own experience

when I first wrote about it five

years ago and many times since.

But there’s much more,

which we will also explore today

with my two guests from

the Cochlear Center,

professor Nick Reed and

Kening Jiang. Nick,

although many people already

know who you are,

please tell everyone a bit about

yourself and what you do

at the Cochlear Center.

Yeah, thanks for having us.

As you said, I’m Nick Reed.

I’m an assistant professor in

the Department of Epidemiology

at the Johns Hopkins Bloomberg

School of Public Health.

I’m a clinical audiologist by

background in training,

but my research mostly lies at

the intersection of epidemiology

and gerontology related

to hearing loss.

Thank you. And Kening,

please tell us about yourself.

Thank you.

My name is Kening Jiang.

I’m currently a third year PhD

student in epidemiology of aging

at Johns Hopkins and also

training at the Cochlear Center.

My advisors are Dr.

Jennifer Deal and Dr.

Nicholas Reed.

My research interests are in

cognitive impairment and

dementia among other adults,

especially in how modifiable

risk factors,

including hearing loss,

might be targeted for dementia

prevention. Okay,

thank you both.

It’s great to have you today.

Kening,

I’d like to open with the recent

study on hearing loss and

fatigue for which you

are the lead author.

You and your co authors

concluded in part that,

and I’m quoting here,

participants with hearing loss

were more likely to report

fatigue for more than half the

days and nearly every day,

compared with not

having fatigue.

Can you elaborate on

those findings?

Yeah, sure. In this study,

we use data from the National

Health and Diet Nutrition

Examination Survey,

or NHANES consists of a nationally

representative sample of over

3000 participants as they’re

middle aged or older.

We found cross sectional

association between audiometric

hearing loss and the higher

frequency of self reported

fatigue.

And did you control for other

factors related to fatigue

as well as hearing loss?

Even societal factors,

other lifestyle factors,

other comorbidities?

We control for a few,

like demographic factors and

also clinical factors.

For example, like.

Cardiovascular diseases,

but I think the data limited.

There might be more like social

factors that need to be

okay. Okay,

and so then really relying

on the NHANES data,

then you’re able to control for

a lot of different factors.

Now,

did you also study not only

hearing losses related

to fatigue,

but what effect treating hearing

loss has on fatigue?

In other words,

if I have my hearing loss

treated and hearing aids I

prescribed and I wear them,

what effect does that have

on my fatigue level?

I think, unfortunately,

in this data set,

we found that the number of

participants with hearing aids

are too small for study the

effect of hearing aids.

But this certainly is a really

interesting topic to explore

in future studies.

Okay,

so it’s really a primary study

on the relationship between

fatigue and hearing loss.

Can you unpack your findings

in a little more detail?

Exactly age groups,

what level of hearing loss and

how strong was the correlation

with fatigue? Yeah,

both the studies was done among

middle aged and older,

so participants age 40

years and older,

and we found that participants

with hearing loss are more than

two times more likely to report

higher frequency of fatigue.

Okay, interesting.

And that kind of begs

a question then,

since you didn’t see those

results in younger people.

Is overall aging and cognitive

state cognitive health that

comes with aging also a factor?

I think in NHANES,

the two cycles we use were

not cognitive measures,

so we were not able to consider

the cognitive status of

the participants.

But we did have a relatively

wider range of the age from

middle aged adults

to older adults.

We did an explorative analysis

and found that the association

was actually slightly stronger

among younger participants.

But this is also complicated,

and we cannot draw a conclusion

because the prevalence of

hearing loss is also lower among

younger participants than the

estimates are statistically

unstable in status.

So my takeaway here is that this

is like early primary research

on the relationship between

hearing loss and fatigue level.

It sounds like there’s a lot of

avenues for further research.

Do you have any plans for

additional research and what

questions you want to

explore if you are,

and I’ll ask that of

either one of you.

I think that’s a great question.

When we started thinking about

this study and in this podcast,

we’ll talk a lot about Think

Kening’s work. I mean,

she’s a superstar and she’s

doing some really interesting

stuff in this area, but.

Specific to this question.

We started looking through

the research,

and this isn’t a new concept.

There’s a lot of laboratory

based studies focusing on the

idea of auditory sort of either

they’ll call it auditory

fatigue,

auditory working memory.

It depends what kind

of lab it’s in.

But it’s all about this concept

of some sort of cognitive load

based off of hearing loss.

But we hadn’t seen it on

a population level.

And you asked this point, Andy.

You made the point that it could

be related to cognition and it

could be a key variable there.

We can’t do that mediation

analysis, unfortunately,

with the data we’re limited by.

But our future studies,

we’ve added hearing to a few

major studies in the country

that are longitudinal,

and they even do a decent job of

thinking about whether the

fatigue is physical fatigue or

cognitive fatigue and the sort

of difference there of what

that could mean. Right.

Is it this overall exhaustion?

Is it physical function,

like lack of physical activity

to some extent,

or is it really this processing

idea? And so our future work,

I think,

wants to go down that pathway.

And then you hit the nail on the

head to start thinking about

fatigue as sort of a mediator

and a strong

sign of potential for cognitive

decline related to hearing loss

or other changes in lifestyle,

to be honest with you,

like social isolation and

decreased physical activity.

And I love the different lines

of research you’re taking

because they all seem to fit in

a pattern cognitive ability,

fatigue level, hearing loss,

social isolation, depression.

They all fit in some way.

But exactly how and what are

the causative elements?

Really something I’m looking

forward to seeing your group

explore more detail as we go.

And interestingly,

in some of the studies

that Kening has led,

sleep also factors into it.

And so I know you’ve done

several studies on the

relationship between sleep

quality and hearing loss,

including even a potential link

with cognitive aging as well.

And so you’re kind of

triangulating with the ACHIEVE

study a little bit if you’re

looking at the relationship of

sleep and hearing loss and

cognitive ability or

cognitive decline.

So what kinds of research

have you actually done?

Describe for the audience what

you’ve done and what the

key results are. Yeah,

I have several studies

investigating sleep disturbances

as risk factors for hearing

loss. Previously,

I found there were previous

studies showing some initial

evidence in clinical samples,

especially people with sleep

disorder breathing might

have hearing loss.

So I decided to start that with

an NHANES analysis,

our study found that people with

longer sleep duration were more

likely to have high frequency

audiometric hearing loss.

Then I was decided to move to

another data set to see to

establish the temporal

relationship between sleep

disturbance and hearing

loss after 20 years.

And we found that

there are different sleep

characteristics that are

associated with hearing

function. For example,

longer sleep duration,

and sleep disordered

breathing and daytime sleepiness

are risk factors for

hearing loss.

But I think the evidence

regarding potential mechanisms

are still unclear.

Well,

one of the things that really

surprised me in reading the

studies was that you mentioned

long sleep.

And it was spelled out more

specifically is sleeping more

than 8 hours was associated with

increased risk of hearing loss.

Now,

is that because longer than 8

hours sleep is associated with

poor sleep or is it about

the timing of sleep,

the time period of sleep,

even if you’re sleeping well?

And I guess the related question

is what about a person who

sleeps poorly for less

than 8 hours?

Yeah,

I think generally for studies

linking sleep duration and

adverse health outcomes,

we kind of see like a U shape

relationship that people with

short sleep duration and the

long sleep duration both have

elevated risk of some kind of

health outcomes when compared

to those with, for example,

seven to 8 hours of sleep.

In our study linking sleep

disturbance with hearing loss,

we kind of see the relationship

but only long sleep duration

group shows significant

association.

This probably due to

maybe underlying medical

conditions that leading people

to sleep longer and also is kind

of linked to hearing loss,

but it’s unclear.

Okay. And of course,

I’m going to ask you to set your

scientist hat aside

a little bit,

then speculate because I suppose

it would also drive the

direction of future studies.

And that is what do you suspect

is the direction of the link

between sleep quality and

hearing loss and which direction

is it going?

So currently in our side,

we are viewing sleep

disturbances as a risk

factor for hearing loss.

So it’s like sleep disturbance

causing hearing loss,

but because complexity of the

relationship and also because

sleep and the hearing both

have multiple aspects,

so the direction might be actually

more complex than

we are not.

investigating

It might go bi directional also

from hearing loss to

sleep disturbance,

but we haven’t done much

with that direction.

But it’s still possible.

For example,

hearing loss can cause, like,

social isolation and depression,

and that might impact further

sleep characteristics.

Okay, and what about tinnitus?

Is that part of the study in any

way since there’s a good

correlation with tinnitus and

hearing loss and tinnitus

can disturb your sleep?

I think we haven’t done that,

but there might be an association.

But I think that might be

different because tinnitus is

kind of not the same as

audiometric hearing loss. Okay.

No, it makes perfect sense.

I mean, arguably,

hearing is the most complex

sensory experience we have,

and therefore the relationship

with a variety of different

health comorbidities is going

to be complex. And you both,

I think,

have job security in trying to

parse all this out and actually

look for causation in

different ways.

I think you’re going to be at

this for a long, long time.

But I also think it’s critical

because we know there is a

relationship between a number of

ill health effects

and hearing loss.

And as we try to drive towards

greater adoption of

hearing care,

understanding how that will

improve other quality of life

factors with people,

I think is extremely important.

So given this whole body of

research we’ve been talking

about and I’m going to ask

this of you, Nick,

because you’re kind of standing

by watching Kening produce

this stuff.

I know you’re a co author,

but you said yourself she’s

leading a lot of this.

What are the key takeaways from

all this research so

far in your mind?

So I think one of the key

takeaways is that it is a

complex relationship.

And the thing that I think we

have to think about here is

sleep is related to

cognitive decline.

Hearing is related to cognitive

decline. And to Kening’s point,

she used an epidemiologic term

and then sort of explained it.

We see a U shaped curve and what

that means, as she said,

know, with sleep, for example,

you see these associations where

it’s like hearing loss is both

associated with really short

sleep, potentially,

and really long sleep. Now,

we’ve only identified in

really long sleep,

but Kening’s also got some

signals in the data that might

suggest there is this nonlinear,

not clear path.

And then it gets into,

as Kening said,

there’s a synergy here that

one may cause the other,

and the other may exacerbate

the other once it’s caused,

and we don’t know the

full direction.

So I think that takeaway

is that we know.

There is some sort

of association.

We don’t know the full direction

of the relationship,

but we also know they’re both

important for brain health.

And if you really start to

think big picture here,

the ACHIEVE results have come

out and we’re seeing that, yes,

we have a result, right?

It’s being sort of phrased as

those who are more at risk

for cognitive decline,

we see some protection. Right?

But the other way to think about

this is the findings are

complex. I mean,

you say job security and I agree

with you even in that context.

What are the factors that we

need to understand of who’s

really going to benefit from

hearing care to prevent

cognitive decline? For example,

it’s clear that, it’s not

a one size fits all.

This is going to prevent

everything and right now we’re

only seeing on a population

level.

But I think Kening’s work is

starting to inspire a lot of

us at the Cochlear Center.

Jennifer Deal, myself,

Frank Lin, Adam Spira is

actually a sleep researcher who

is very well respected,

who’s now involved in hearing

research. Because of Kening,

I think her body of work is

making us start to think about

what are those sort of

individual factors,

almost like you might think of

it as like precision audiology

in the sense of who’s going to

benefit for this outcome

or cognitive decline.

And that’s just one of many

outcomes we could think

about here.

But I just love the way

Kening’s opening doors for us

and helping us to realize, know,

to date everything’s been one

exposure
and one outcome and the

world doesn’t work that way,

right?

We are complex beings with so

many different factors that we

need to start thinking about how

everything sort of interacts

together to really paint the

right picture for care

models going forward.

I think that’s really a great

way of putting it.

It’s a great way to

wrap this up.

I’ll only add that I really like

taking it almost from well,

not almost from,

but really from an

epidemiological point of view

because we talk about the

individual experience a lot.

I mean,

empirically we know that

if you don’t hear well,

you’re not going to enjoy

yourself as much in social

situations and therefore you’ll

tend to isolate yourself more

and all this sort of thing.

But to study that on population

basis is going to be hugely

important going forward and

looking forward to a lot of

positive outcomes that come from

this research in the years

ahead. So as we wrap it up,

I’ll mention that I’ll put links

to this research in the show

notes so that people can refer

to it and read it.

And I’m going to ask you,

Kenning, before we go,

do you have any last thoughts on

the research and the directions

you’re taking and

the conclusions?

I think like, hearing loss,

and sleep disturbance, are also

prevalent among adults,

also modifiable even in late

life and also associated with

adverse health outcomes

and with.

pathologies.

So I think it’s important to

take other prevalent risk

factors into account and

have a bigger picture of how

that might mean to other

words else outcomes.

Okay,

and you said something there

that actually triggered

a thought in my mind,

because you said even

later in life,

which reminded me that your

sleep studies are showing

an effect at midlife.

And that reminded me of the

Lancet Commission report

of a few years ago,

which also pointed to treatment

at midlife as being a mitigating

factor. In other words,

waiting until late in life is

almost too late compared to

addressing hearing

loss at midlife.

And that’s the direction

they were pointing at.

And so

I’ll ask you as part of

your closing, Nick,

if that makes a lot of sense,

that you’re starting to see the

need to address hearing loss at

midlife to have the greatest

positive effect.

Yeah, that’s a great question.

So we don’t have that kind

of evidence yet.

I have sort of two thoughts

there. One,

we really don’t have that kind

of evidence. And ACHIEVE,

for example,

has actually focused on

an older group, right?

It’s definitely older.

I think that future work needs

to be done on where the sort of

optimal engagement is in terms

of from the development of

hearing loss or first noticing

signs of hearing loss and

when you intervene.

I think that one of the

misconceptions with the Lancet

Commission is they defined

it as midlife,

and it has more to do with the

aberration of the age ranges.

In one of the studies that was

included in this risk

ratio calculation,

which was a very wide

range study,

and it sort of as a

mean and a median,

ended up being sort of

much younger than the

other two studies.

And then the Commission,

based off the way they were sort

of aligning and categorizing

things, they were like, oh,

well,

hearing loss must be a midlife.

But if you put all three

studies together,

it’s actually much more of

a late life factor.

We’ve actually got some

really cool new data.

Not trying to be super

self promotional,

but we just did prevalence rates

of hearing loss among oldest old

adults because we finally got

hearing into the National Health

Aging Trend Study,

which is a nationally

representative sample that

oversamples adults over 90 years

of age. And we really,

really see the prevalence of

hearing loss just skyrocket when

we get over the age of 70.

And once we get to the age

of 90, for example,

everyone ubiquitously has what

we would consider a clinically

defined hearing loss.

So it really is a late life

thing as far as a population

level goes.

But I love the way that you

eloquently put this. Like,

when does it matter

to intervene?

Because maybe those signs

are starting in.

Maybe if you consider fifty s

and sixty s midlife what’s

happening there?

I do

maybe an even better way to

think of this is like instead

of midlife versus late life,

how fast do we need to react?

And then maybe actually the

Epidemiologic way to think of

this, not to bore your audience,

but does that reaction time

matter differently for if

hearing loss starts when you’re

60 versus if it starts when

you’re 70, right.

Do we have a finite window

that’s even smaller to actually

get hearing aids on somebody to

prevent cognitive decline?

Potentially.

And those questions are

definitely not answered right

now and ACHIEVE is not the study

to answer them necessarily.

But there are – Justin Golub at

Columbia is leading some really

interesting work that builds off

of ACHIEVE and those sorts of

studies will turn into, I think,

really fascinating pieces over

the coming years in terms

of this, again,

like idea of precision

audiology, if you will.

Well,

I can’t resist saying that this

is going to be so important when

we really talk about addressing

the global pandemic

of hearing loss.

You think about regions of the

world where hearing care

is hard to get,

where the national health

systems are overloaded.

When you can really start to pin

down what the positive effects

of addressing hearing loss

and when what those are,

then you can really think about

delivering efficient hearing

care in a way that then

downstream takes a lot of burden

off the national health system

in terms of those other

comorbidities.

So this is hugely important

research from a global

perspective.

So at least for me as an

audience member of

one and of course, ya know,

any study with an N

of 1 is worthless.

But I think for that reason the

Epidemiological approach

is extremely important.

And so I appreciate you both

spending some time with

me today. Nick,

how can people reach you if they

have questions or want to talk

further about your work? Yeah,

honestly,

Hopkins is not bashful at all.

Our email addresses are

basically public information.

If you’d like to learn more

about our center as a whole,

Kenning’s work,

our other trainees work,

we
honestly have some phenomenal

PhD students right now doing

some amazing things.

You can google search the

Cochlear Center for Hearing and

Public Health at Johns Hopkins

and you will find our website.

Come up right at the

you know,

we’ve got links to all of

our studies on there.

Terrific. Kening,

anything you want to add,

just find us on our website.

Okay, very good. Well,

thank you both for joining me

today and keep up

the great work.

I’m really looking forward to

seeing what continues to flow

out of the Cochlear Center

in the months and years

ahead and thanks for everyone for

watching or listening to

This Week in Hearing.