Page 20 - 《运动与健康科学》(英文)2024年第2期

TaggedAPTARAEnd142 M. Rodriguez-Ayllon et al.
activity differentially modulates Ab levels in the brain, CSF, or cognitively impaired) to identify individuals most affected by
blood, previous studies showed that Ab levels increase in AD physical activity. Second, we could not explore the moderating
when it is assessedinthe brainwithPET 69 and decrease when roles of several variables that might have influenced the meta-
measured in the CSF. 70 One possible explanation for this is that analytic results (e.g., Apolipoprotein E genotype). Third, our
aggregation of Ab into plaques and greater retention of the search was limited to middle-aged and older adults. Since
peptide in the brain results in reduced diffusion of Ab into the amyloid deposition can occur in an earlier stage of life, 71
CSF. Lastly, although most studies suggest higher levels of future studies can include younger populations to explore
brain and blood Ab are predictive of AD, there are still whether physical activity might affect Ab differently in earlier
some inconsistencies between studies. 8 Therefore, more stages of life. Lastly, given the scarcity of studies in the meta-
replication within cohorts and more standardization with analysis, future RCTs on this topic are needed.TaggedAPTARAEnd
respect to analytical procedures focusing on Ab are neces- TaggedAPTARAPThis systematic review also has some strengths. First, it
sary to understand the relationship between physical activity follows the PRISMA guidelines for systematic review
methodology. Second, we registered the study in PROS-
and blood Ab.TaggedAPTARAEnd
PERO databases before starting the specific search. Third,
we organized a list of excluded articles and the reasons for
TaggedAPTARAH24.3. Literature gaps and future researchTaggedAPTARAEnd
TaggedAPTARAP
exclusion. Finally, we included different databases and all
TaggedAPTARAEndTaggedAPTARAP There is a need to determine whether the effect of physical types of study designs.TaggedAPTARAEnd
activity on Ab varies by type, duration, intensity, or
TaggedAPTARAH15. ConclusionTaggedAPTARAEnd
frequency of physical activity.TaggedAPTARAEnd
TaggedAPTARAEndTaggedAPTARAP Intervention studies might assess Ab in the blood, the brain,
TaggedAPTARAPResearch in the field of cognitive aging has attempted to
and the CSF to explore whether the effect of exercise on Ab
understand the reasons for individual variability in cognitive
decline. This body of work is highly convinced that physical
might vary by type of tissue.TaggedAPTARAEnd
TaggedAPTARAP Future intervention studies might compare the exercise 72
activity affects cognitive and brain health outcomes.
group with a standardized non-active control group (e.g.,
However, more research is needed to understand how physical
participants who continued their usual routines) to avoid 72
activity shapes the aging brain. In this context, the present
systematic review suggests physical activity might moderately
any effect-size bias.TaggedAPTARAEnd
TaggedAPTARAP More large-scale multicenter intervention studies are
reduce blood Ab, which is 1 possible mechanism for deliv-
needed to test the effectiveness of physical activity for
ering the benefits of physical activity, in older people.
However, since the results neared but did not reach statistical
modulating Ab levels.TaggedAPTARAEnd
TaggedAPTARAP Long-term physical activity interventions are needed to
significance, they should be interpreted with caution, espe-
more definitively test the effect of physical activity on
cially given the methodological limitations observed in some
PET-quantified brain Ab. For CSF and blood Ab, the use
of the included studies. Moreover, increased physical activity
of high-performance blood-based Ab assays is needed to
was associated with higher levels of Ab only when it was
reduce the variability in previous studies.TaggedAPTARAEnd
assessed in the CSF. Overall, due to the small number of inter-
TaggedAPTARAP Future interventions should standardize the time interval
vention studies included in the meta-analysis, and to the equivo-
between the final session of the intervention and the brain,
cal findings provided by the observational studies, more studies
blood, and CSF Ab post-intervention assessment since
are needed to understand the role of physical activity in modu-
results may differ (e.g., positive or negative direction)
lating brain, CSF, and blood Ab levels, as well as the implica-
when assessing Ab in acute vs. chronic conditions.TaggedAPTARAEnd
tions for cognitive health. Additionally, future studies should
TaggedAPTARAP Longitudinal population-based studies are needed to continue exploring the potential mechanisms responsible for
explore the long-term associations between physical
the positive effects of physical activity on cognition to spur the
activity and Ab, and to compare the general population
development of more effective interventions and stimulate the
identification of cost-efficient alternative therapies for
with preclinical and clinical stages of AD.TaggedAPTARAEnd
TaggedAPTARAP Due to the possibility of bi-directionality, longitudinal cohort
preventing and treating AD. Finally, although our systematic
studies with physical activity and Ab data at 2 time points
review and meta-analysis cannot provide direct clinical prac-
tice changes, we identified gaps in the literature as well as
are needed to determine the possibility of reverse causality.TaggedAPTARAEnd
TaggedAPTARAP More studies are needed to disambiguate populations most
future perspectives that might guide new research directions in
affected by physical activity as well as set the key stages
the cognitive aging field.TaggedAPTARAEnd
for appreciating Ab changes (e.g., cognitively normal vs.
cognitively impaired).TaggedAPTARAEnd
TaggedAPTARAH1AcknowledgmentsTaggedAPTARAEnd
TaggedAPTARAP In addition to the Ab path, more research is needed to
unravel the potential mechanisms linking physical activity TaggedAPTARAPMRA was funded by the Ram on Areces Foundation. IEC is
supported by the Spanish Ministry of Science and Innovation
with cognition in the elderly.TaggedAPTARAEnd
(RYC2019-027287-I) and the Spanish Ministry of Economy
and Competitiveness (RTI2018-095284-J-100). PSU is
TaggedAPTARAH24.4. Limitations and strengthsTaggedAPTARAEnd
supported by a grant from ANID/BECAS Chile (Grant No.
TaggedAPTARAPOur review has some limitations. First, there were not suffi- 72180543) and through a Margarita Salas grant from the
cient studies in each population (i.e., cognitively normal and Spanish Ministry Universities.TaggedAPTARAEnd