BACKGROUND
The
relationship
between
24-hour
rest-activity
rhythms
(RARs)
and
risk
for
dementia
or
mild
cognitive
impairment
(MCI)
remains
an
area
of
growing
interest.
Previous
studies
were
often
limited
by
small
sample
sizes,
short
follow-ups,
older
participants.
More
are
required
to
fully
explore
the
link
disrupted
RARs
MCI
in
middle-aged
adults.
OBJECTIVE
We
leveraged
UK
Biobank
data
examine
how
RAR
disturbances
correlate
with
developing
METHODS
analyzed
91,517
participants
aged
43
79
years.
Wrist
actigraphy
recordings
used
derive
nonparametric
metrics,
including
activity
level
most
active
10-hour
period
(M10)
its
midpoint,
least
5-hour
(L5)
relative
amplitude
(RA)
cycle
[RA=(M10-L5)/(M10+L5)],
interdaily
stability,
intradaily
variability,
as
well
acrophase
(cosinor
analysis).
Cox
proportional
hazards
models
associations
baseline
subsequent
incidence
MCI,
adjusting
demographic
characteristics,
comorbidities,
lifestyle
factors,
shiftwork
status,
genetic
Alzheimer's
disease.
RESULTS
During
follow-up
up
7.5
years,
555
developed
dementia.
increased
those
lower
M10
(hazard
ratio
[HR]
1.28,
95%
CI
1.14-1.44,
per
1-SD
decrease),
higher
L5
(HR
1.15,
1.10-1.21,
increase),
RA
1.23,
1.16-1.29,
1.32,
1.17-1.49,
variability
1.14,
1.05-1.24,
increase)
advanced
midpoint
0.92,
0.85-0.99,
advance).
These
similar
people
<70
>70
non–shift
workers,
they
independent
cardiovascular
factors.
No
significant
observed
acrophase.
CONCLUSIONS
Based
on
findings
from
a
large
middle-to-older
adults
objective
assessment
almost
8-years
follow-up,
we
suggest
that
suppressed
fragmented
daily
precede
onset
may
serve
biomarkers
preclinical
BACKGROUND
The
relationship
between
24-hour
rest-activity
rhythms
(RARs)
and
risk
for
dementia
or
mild
cognitive
impairment
(MCI)
remains
an
area
of
growing
interest.
Previous
studies
were
often
limited
by
small
sample
sizes,
short
follow-ups,
older
participants.
More
are
required
to
fully
explore
the
link
disrupted
RARs
MCI
in
middle-aged
adults.
OBJECTIVE
We
leveraged
UK
Biobank
data
examine
how
RAR
disturbances
correlate
with
developing
METHODS
analyzed
91,517
participants
aged
43
79
years.
Wrist
actigraphy
recordings
used
derive
nonparametric
metrics,
including
activity
level
most
active
10-hour
period
(M10)
its
midpoint,
least
5-hour
(L5)
relative
amplitude
(RA)
cycle
[RA=(M10-L5)/(M10+L5)],
interdaily
stability,
intradaily
variability,
as
well
acrophase
(cosinor
analysis).
Cox
proportional
hazards
models
associations
baseline
subsequent
incidence
MCI,
adjusting
demographic
characteristics,
comorbidities,
lifestyle
factors,
shiftwork
status,
genetic
Alzheimer's
disease.
RESULTS
During
follow-up
up
7.5
years,
555
developed
dementia.
increased
those
lower
M10
(hazard
ratio
[HR]
1.28,
95%
CI
1.14-1.44,
per
1-SD
decrease),
higher
L5
(HR
1.15,
1.10-1.21,
increase),
RA
1.23,
1.16-1.29,
1.32,
1.17-1.49,
variability
1.14,
1.05-1.24,
increase)
advanced
midpoint
0.92,
0.85-0.99,
advance).
These
similar
people
<70
>70
non–shift
workers,
they
independent
cardiovascular
factors.
No
significant
observed
acrophase.
CONCLUSIONS
Based
on
findings
from
a
large
middle-to-older
adults
objective
assessment
almost
8-years
follow-up,
we
suggest
that
suppressed
fragmented
daily
precede
onset
may
serve
biomarkers
preclinical