Associations between physical activity levels and ATPase inhibitory factor 1 concentrations in older adults

Background:Adenosine triphosphatase inhibitory factor 1(IF1)is a key protein involved in energy metabolism.IF1 has been linked to various agerelated diseases,although its relationship with physical activity(PA)remains unclear.Additionally,the apolipoprotein A-I(apoA-I),a PA-modulated lipoprotein,could play a role in this relationship because it shares a binding site with IF1 on the cell-surface ATP synthase.We examined here the associations between chronic PA and plasma IF1 concentrations among older adults,and we investigated whether apoA-I mediated these associations.Methods:In the present work,1096 healthy adults(63.8%females)aged 70 years and over who were involved in the Multidomain Alzheimer Prevention Trial study were included.IF1 plasma concentrations(square root of ng/mL)were measured at the 1-year visit of the Multidomain Alzheimer Prevention Trial,while PA levels(square root of metabolic equivalent task min/week)were assessed using questionnaires administered each year from baseline to the 3-year visit.Multiple linear regressions were performed to investigate the associations between the first-year mean PA levels and IF1 concentrations.Mediation analyses were conducted to examine whether apoA-I mediated these associations.Mixedeffect linear regressions were carried out to investigate whether the 1-year visit IF1 concentrations predicted subsequent changes in PA.Results:Multiple linear regressions indicated that first-year mean PA levels were positively associated with IF1 concentrations(B=0.021;SE=0.010;p=0.043).Mediation analyses revealed that about 37.7%of this relationship was mediated by apoA-I(B_(ab)=0.008;SE=0.004;p=0.023).Longitudinal investigations demonstrated that higher concentrations of IF1 at the 1-year visit predicted a faster decline in PA levels over the subsequent 2 years(time×IF1:B=0.148;SE=0.066;p=0.025).Conclusion:This study demonstrates that regular PA is associated with plasma IF1 concentrations,and it suggests that apoA-I partly mediates this association.Additionally,this study finds that baseline concentrations of IF1 can predict future changes in PA.However,further research is needed to fully understand the mechanisms underlying these observations.

Cross-sectional associations between cortical thiclmess and physical activity in older adults with spontaneous memory complaints:The MAPT Study

Background:Age-related changes in brain structure may constitute the starting point for cerebral function alteration.Physical activity(PA)demonstrated favorable associations with total brain volume,but its relationship with cortical thickness(CT)remains unclear.We investigated the cross-sectional associations between PA level and CT in community-dwelling people aged 70 years and older.Methods:A total of 403 older adults aged 74.8±4.0 years(mean±SD)who underwent a baseline magnetic resonance imaging examination and who had data on PA and confounders were included.PA was assessed with a questionnaire.Participants were categorized according to PA levels.Multiple linear regressions were used to compare the brain CT(mm)of the inactive group(no PA at all)with 6 active groups(growing PA levels)in 34 regions of interest.Results:Compared with inactive persons,people who achieved PA at a level of 1500-1999 metabolic equivalent task-min/week(i.e.,about6-7 h of brisk walking for exercise) and those who achieved it at 2000-2999 metabolic equivalent task-min/week(i.e.,8-11 h of brisk walking for exercise)had higher CT in the fusiform gyrus and the temporal pole.Additionally,dose-response associations between PA and CT were found in the fusiform gyrus(B=0.011,SE=0.004,adj.p=0.035),the temporal pole(B=0.026,SE=0.009,adj.p=0.048),and the caudal middle frontal gyrus,the entorhinal,medial orbitofrontal,lateral occipital,and insular cortices.Conclusion:This study demonstrates a positive association between PA level and CT in temporal areas such as the fusiform gyrus,a brain region often associated to Alzheimer’s disease in people aged 70 years and older.Future investigations focusing on PA type may help to fulfil remaining knowledge gaps in this field.