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1.
Neurobiol Aging ; 137: 94-104, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38460470

RESUMO

The study examined resting state functional connectivity (rs-FC) associated with moderate-to-vigorous physical activity (MV-PA), sedentary time (ST), TV viewing, computer use, and their relationship to cognitive performance in older adults. We used pre-intervention data from 119 participants from the Fit & Active Seniors trial. Multivariate pattern analysis revealed two seeds associated with MV-PA: right superior frontal gyrus (SFG; spanning frontoparietal [FPN] and ventral attention networks [VAN]) and right precentral (PrG) and postcentral gyri (PoG) of the somatosensory network (SN). A positive correlation between the right SFG seed and a cluster spanning default mode (DMN), dorsal attention (DAN), FPN, and visual networks (VIS) was linked to higher fluid intelligence, as was FC between the right PrG/PoG seed and a cluster in VIS. No significant rs-FC patterns associated with ST, TV viewing, or computer use were found. Our findings suggest that greater functional integration within networks implementing top-down control and within those supporting visuospatial abilities, paired with segregation between networks critical and those not critical to top-down control, may help promote cognitive reserve in more physically active seniors.


Assuntos
Conectoma , Humanos , Idoso , Individualidade , Córtex Pré-Frontal , Imageamento por Ressonância Magnética , Encéfalo/diagnóstico por imagem
3.
Cereb Circ Cogn Behav ; 6: 100203, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38292016

RESUMO

As the emerging treatments that target grey matter pathology in Alzheimer's Disease have limited effectiveness, there is a critical need to identify new neural targets for treatments. White matter's (WM) metabolic vulnerability makes it a promising candidate for new interventions. This study examined the age and sex differences in estimates of axonal content, as well the associations of with highly prevalent modifiable health risk factors such as metabolic syndrome and adiposity. We estimated intra-axonal volume fraction (ICVF) using the Neurite Orientation Dispersion and Density Imaging (NODDI) in a sample of 89 cognitively and neurologically healthy adults (20-79 years). We showed that ICVF correlated positively with age and estimates of myelin content. The ICVF was also lower in women than men, across all ages, which difference was accounted for by intracranial volume. Finally, we found no association of metabolic risk or adiposity scores with the current estimates of ICVF. In addition, the previously observed adiposity-myelin associations (Burzynska et al., 2023) were independent of ICVF. Although our findings confirm the vulnerability of axons to aging, they suggest that metabolic dysfunction may selectively affect myelin content, at least in cognitively and neurologically healthy adults with low metabolic risk, and when using the specific MRI techniques. Future studies need to revisit our findings using larger samples and different MRI approaches, and identify modifiable factors that accelerate axonal deterioration as well as mechanisms linking peripheral metabolism with the health of myelin.

4.
Int J Mol Sci ; 24(24)2023 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-38139169

RESUMO

The aim of this study was to analyze the relationship between the serum levels of soluble transferrin receptor (sTfR) and interleukin 4 (IL-4), and the disease activity and organ manifestations in SLE patients. We studied 200 SLE patients and 50 controls. We analyzed disease activity, organ involvement, serum sTfR, IL-4 and interleukin-6 (IL-6) levels, and antinuclear and antiphospholipid antibody profiles. The median serum levels of sTfR (p > 0.000001) and IL-4 (p < 0.00001) were higher in the study group than in the controls. SLE patients, compared to the controls, had significantly lower HGB levels (p < 0.0001), a lower iron concentration (p = 0.008), a lower value of total iron-binding capacity (TIBC) (p = 0.03), and lower counts of RBC (p = 0.004), HCT (p = 0.0004), PLT (p = 0.04), neutrophil (p = 0.04), and lymphocyte (p < 0.0001). Serum sTfR levels were negatively correlated with lymphocyte (p = 0.0005), HGB (p = 0.0001) and HCT (p = 0.008), and positively correlated with IL-4 (p = 0.01). Elevated serum sTfR > 2.14 mg/dL was associated with an increased risk of myocardial infarction (OR: 10.6 95 CI 2.71-464.78; p = 0.001), ischemic heart disease (OR: 3.25 95 CI 1.02-10.40; p = 0.04), lung manifestations (OR: 4.48 95 CI 1.44-13.94; p = 0.01), and hematological manifestations (OR: 2.07 95 CI 1.13-3.79; p = 0.01), and with a reduced risk of neuropsychiatric manifestations (OR: 0.42 95 CI 0.22-0.80; p = 0.008). Serum IL-4 was negatively correlated with CRP (p = 0.003), and elevated serum IL-4 levels > 0.17 mg/L were associated with a reduced risk of mucocutaneous manifestations (OR: 0.48 95 CI 0.26-0.90; p = 0.02). In SLE patients, elevated serum levels of sTfR were associated with an increased risk of cardiovascular, pulmonary, and hematological manifestations, and with a decreased risk of neuropsychiatric manifestations. In contrast, elevated serum IL-4 levels were associated with a decreased risk of mucocutaneous manifestations.


Assuntos
Interleucina-4 , Lúpus Eritematoso Sistêmico , Humanos , Ferro , Receptores da Transferrina , Interleucina-6 , Pulmão
5.
Pharmaceuticals (Basel) ; 16(12)2023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-38139760

RESUMO

OBJECTIVE: this study aims to comprehensively compare neuropsychological, psychopathological, anthropometric, biochemical, pharmacological, and lifestyle variables between 27 male schizophrenic patients (SZ group) and 30 age- and sex-matched healthy male controls (HC group). METHODS: participants underwent a battery of neuropsychological tests including the Trail Making Test (TMT), Stroop Color-Word Interference Test, and Verbal Fluency Test. Psychopathological symptoms in the SZ group were evaluated using the Positive and Negative Syndrome Scale (PANSS). Anthropometric measurements such as body weight, height, BMI, and waist circumference were taken. Biochemical markers measured included fasting glucose, total cholesterol, triglycerides, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and fasting insulin. Lifestyle factors were assessed through a questionnaire for the study of views and eating habits of people aged 16 to 65. RESULTS: the HC group outperformed the SZ group in the TMT_A test and the Stroop test, but no significant differences were observed in the TMT_B test or in phonemic fluency tests. No correlation was found between age and PANSS scores within the SZ group. Anthropometrically, the SZ group had higher body weight, waist circumference, and BMI, with no difference in height. Biochemically, the HC group had higher HDL cholesterol levels but lower insulin and insulin resistance indices. Pharmacological assessment showed a more significant impact on body weight among SZ patients taking second-generation antipsychotics. Lifestyle factors such as diet and screen time were comparable between groups, but the SZ group reported longer sleep duration and lower leisure time activity. CONCLUSIONS: our study highlights distinct neuropsychological, pharmacological, anthropometric, and biochemical differences between male schizophrenic patients and healthy controls. The results underscore the complexity of schizophrenia and point toward the need for a multi-faceted approach to its management and understanding.

6.
Biomolecules ; 13(6)2023 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-37371554

RESUMO

Interleukin 10 (IL-10) plays a role in inflammation and cell-type responses. The anti-SS-A/Ro antibody contributes to leucopenia, and cutaneous and neonatal lupus. OBJECTIVES: To evaluate the association between serum IL-10 levels and autoantibodies, disease activity and organ involvement in systemic lupus erythematosus (SLE) patients. PATIENTS AND METHODS: We studied 200 SLE patients and 50 controls. We analyzed organ involvement, disease activity, serum IL-10 and interleukin-6 (IL-6) levels, and antinuclear and antiphospholipid antibody profiles. RESULTS: Serum IL-10 and IL-6 levels were higher in SLE patients than in controls (all p < 0.00001). Serum IL-10 levels were positively correlated with IL-6 (p < 0.00001), CRP (p < 0.00001), fibrinogen (p = 0.003), and ESR (p < 0.00001), and negatively correlated with hemoglobin (p = 0.0004) and lymphocytes (p = 0.01). Serum IL-6 levels were positively correlated with CRP (p < 0.00001), fibrinogen (p = 0.001), and ESR (p < 0.00001); and negatively correlated with hemoglobin (p = 0.008) and lymphocytes (p = 0.03). Elevated serum IL-10 levels were associated with an increased risk of anti-SS-A/Ro antibody positivity (p = 0.03). Elevated serum IL-6 levels were associated with an increased risk of heart (p = 0.007) and lung (p = 0.04) involvement. CONCLUSIONS: In SLE patients, increased serum IL-10 levels were associated with increased disease activity and risk of anti-SS-A/Ro antibody positivity.


Assuntos
Autoanticorpos , Interleucina-10 , Interleucina-6 , Lúpus Eritematoso Sistêmico , Humanos , Recém-Nascido , Autoanticorpos/imunologia , Interleucina-10/sangue , Interleucina-10/imunologia , Interleucina-6/sangue , Interleucina-6/imunologia , Leucopenia/sangue , Leucopenia/imunologia , Lúpus Eritematoso Sistêmico/imunologia
7.
Front Neurol ; 14: 1094313, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37139071

RESUMO

In the past 20 years, white matter (WM) microstructure has been studied predominantly using diffusion tensor imaging (DTI). Decreases in fractional anisotropy (FA) and increases in mean (MD) and radial diffusivity (RD) have been consistently reported in healthy aging and neurodegenerative diseases. To date, DTI parameters have been studied individually (e.g., only FA) and separately (i.e., without using the joint information across them). This approach gives limited insights into WM pathology, increases the number of multiple comparisons, and yields inconsistent correlations with cognition. To take full advantage of the information in a DTI dataset, we present the first application of symmetric fusion to study healthy aging WM. This data-driven approach allows simultaneous examination of age differences in all four DTI parameters. We used multiset canonical correlation analysis with joint independent component analysis (mCCA + jICA) in cognitively healthy adults (age 20-33, n = 51 and age 60-79, n = 170). Four-way mCCA + jICA yielded one high-stability modality-shared component with co-variant patterns of age differences in RD and AD in the corpus callosum, internal capsule, and prefrontal WM. The mixing coefficients (or loading parameters) showed correlations with processing speed and fluid abilities that were not detected by unimodal analyses. In sum, mCCA + jICA allows data-driven identification of cognitively relevant multimodal components within the WM. The presented method should be further extended to clinical samples and other MR techniques (e.g., myelin water imaging) to test the potential of mCCA+jICA to discriminate between different WM disease etiologies and improve the diagnostic classification of WM diseases.

8.
Cereb Circ Cogn Behav ; 5: 100180, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38162292

RESUMO

Metabolic syndrome (MetS) is a cluster of conditions that affects ∼25% of the global population, including excess adiposity, hyperglycemia, dyslipidemia, and elevated blood pressure. MetS is one of major risk factors not only for chronic diseases, but also for dementia and cognitive dysfunction, although the underlying mechanisms remain poorly understood. White matter is of particular interest in the context of MetS due to the metabolic vulnerability of myelin maintenance, and the accumulating evidence for the importance of the white matter in the pathophysiology of dementia. Therefore, we investigated the associations of MetS risk score and adiposity (combined body mass index and waist circumference) with myelin water fraction measured with myelin water imaging. In 90 cognitively and neurologically healthy adults (20-79 years), we found that both high MetS risk score and adiposity were correlated with lower myelin water fraction in late-myelinating prefrontal and associative fibers, controlling for age, sex, race, ethnicity, education and income. Our findings call for randomized clinical trials to establish causality between MetS, adiposity, and myelin content, and to explore the potential of weight loss and visceral adiposity reduction as means to support maintenance of myelin integrity throughout adulthood, which could open new avenues for prevention or treatment of cognitive decline and dementia.

9.
Med Sci Sports Exerc ; 54(9): 1483-1492, 2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-35482769

RESUMO

INTRODUCTION: Individual differences in brain structure and function in older adults are potential proxies of brain reserve or maintenance and may provide mechanistic predictions of adherence to exercise. We hypothesized that multimodal neuroimaging features would predict adherence to a 6-month randomized controlled trial of exercise in 131 older adults (age, 65.79 ± 4.65 yr, 63% female), alone and in combination with psychosocial, cognitive, and health measures. METHODS: Regularized elastic net regression within a nested cross-validation framework was applied to predict adherence to the intervention in three separate models (brain structure and function only; psychosocial, health, and demographic data only; and a multimodal model). RESULTS: Higher cortical thickness in somatosensory and inferior frontal regions and less surface area in primary visual and inferior frontal regions predicted adherence. Higher nodal functional connectivity (degree count) in default, frontoparietal, and attentional networks and less nodal strength in primary visual and temporoparietal networks predicted exercise adherence ( r = 0.24, P = 0.004). Survey and clinical measures of gait and walking self-efficacy, biological sex, and perceived stress also predicted adherence ( r = 0.17, P = 0.056); however, this prediction was not significant when tested against a null test statistic. A combined multimodal model achieved the highest predictive strength ( r = 0.28, P = 0.001). CONCLUSIONS: Our results suggest that there is a substantial utility of using brain-based measures in future research into precision and individualized exercise interventions older adults.


Assuntos
Encéfalo , Terapia por Exercício , Idoso , Encéfalo/diagnóstico por imagem , Exercício Físico , Terapia por Exercício/métodos , Feminino , Marcha , Humanos , Masculino , Pessoa de Meia-Idade , Caminhada
10.
Artigo em Inglês | MEDLINE | ID: mdl-35329061

RESUMO

Certain exposures related to agricultural work have been associated with neurological disorders. To date, few studies have included brain health measurements to link specific risk factors with possible neural mechanisms. Moreover, a synthesis of agricultural risk factors associated with poorer brain health outcomes is missing. In this systematic review, we identified 106 articles using keywords related to agriculture, occupational exposure, and the brain. We identified seven major risk factors: non-specific factors that are associated with agricultural work itself, toluene, pesticides, heavy metal or dust exposure, work with farm animals, and nicotine exposure from plants. Of these, pesticides are the most highly studied. The majority of qualifying studies were epidemiological studies. Nigral striatal regions were the most well studied brain area impacted. Of the three human neuroimaging studies we found, two focused on functional networks and the third focused on gray matter. We identified two major directions for future studies that will help inform preventative strategies for brain health in vulnerable agricultural workers: (1) the effects of moderators such as type of work, sex, migrant status, race, and age; and (2) more comprehensive brain imaging studies, both observational and experimental, involving several imaging techniques.


Assuntos
Exposição Ocupacional , Praguicidas , Agricultura , Animais , Encéfalo/diagnóstico por imagem , Fazendeiros , Humanos , Exposição Ocupacional/efeitos adversos , Praguicidas/análise , Fatores de Risco
11.
Sci Rep ; 12(1): 940, 2022 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-35042916

RESUMO

Sedentary behaviors are increasing at the cost of millions of dollars spent in health care and productivity losses due to physical inactivity-related deaths worldwide. Understanding the mechanistic predictors of sedentary behaviors will improve future intervention development and precision medicine approaches. It has been posited that humans have an innate attraction towards effort minimization and that inhibitory control is required to overcome this prepotent disposition. Consequently, we hypothesized that individual differences in the functional connectivity of brain regions implicated in inhibitory control and physical effort decision making at the beginning of an exercise intervention in older adults would predict the change in time spent sedentary over the course of that intervention. In 143 healthy, low-active older adults participating in a 6-month aerobic exercise intervention (with three conditions: walking, dance, stretching), we aimed to use baseline neuroimaging (resting state functional connectivity of two a priori defined seed regions), and baseline accelerometer measures of time spent sedentary to predict future pre-post changes in objectively measured time spent sedentary in daily life over the 6-month intervention. Our results demonstrated that functional connectivity between (1) the anterior cingulate cortex and the supplementary motor area and (2) the right anterior insula and the left temporoparietal/temporooccipital junction, predicted changes in time spent sedentary in the walking group. Functional connectivity of these brain regions did not predict changes in time spent sedentary in the dance nor stretch and tone conditions, but baseline time spent sedentary was predictive in these conditions. Our results add important knowledge toward understanding mechanistic associations underlying complex out-of-session sedentary behaviors within a walking intervention setting in older adults.


Assuntos
Encéfalo/fisiologia , Motivação/fisiologia , Comportamento Sedentário , Idoso , Mapeamento Encefálico/métodos , Conectoma/métodos , Exercício Físico/psicologia , Terapia por Exercício/métodos , Feminino , Previsões/métodos , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Descanso/fisiologia , Descanso/psicologia , Fatores de Tempo
12.
Front Hum Neurosci ; 15: 741582, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34483870
13.
Pharmaceuticals (Basel) ; 14(6)2021 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-34205729

RESUMO

Treatment with antidepressants is often insufficiently effective, especially in treatment-resistant depression. In such a situation, it is possible to change the drug, add a second antidepressant, or use pharmacological and non-pharmacological methods of augmenting the effect of pharmacotherapy. New methods that may fall into the scope of multi-module depression treatment as an augmentation of depression treatment are whole body cryotherapy (WBC) and hyperbaric oxygen treatment (HBOT). 545 records were selected and analyzed for these two treatments and finally three clinical trials were selected for analysis. The review also includes data on the possibility of using WBC and HBOT in somatic indications and in organic mental syndromes. Despite the small number of studies on the effectiveness of WBC or HBOT in depression, the current data show that both methods may be effective in the treatment of depression. WBC may be effective in the augmentation of antidepressants, and additionally, it is a method in which a quick antidepressant effect is obtained. HBOT may be effective in endogenous depression, just as it is effective in the treatment of somatic depression symptoms. The results are very preliminary, but if confirmed in subsequent studies, both WBC and HBOT may become new treatment options in treating depression. The authors point to the need and directions for further research into these treatment methods as an augmentation strategy for pharmacological treatment of depression.

14.
Neuroimage ; 239: 118305, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34174392

RESUMO

White matter deterioration is associated with cognitive impairment in healthy aging and Alzheimer's disease. It is critical to identify interventions that can slow down white matter deterioration. So far, clinical trials have failed to demonstrate the benefits of aerobic exercise on the adult white matter using diffusion Magnetic Resonance Imaging. Here, we report the effects of a 6-month aerobic walking and dance interventions (clinical trial NCT01472744) on white matter integrity in healthy older adults (n = 180, 60-79 years) measured by changes in the ratio of calibrated T1- to T2-weighted images (T1w/T2w). Specifically, the aerobic walking and social dance interventions resulted in positive changes in the T1w/T2w signal in late-myelinating regions, as compared to widespread decreases in the T1w/T2w signal in the active control. Notably, in the aerobic walking group, positive change in the T1w/T2w signal correlated with improved episodic memory performance. Lastly, intervention-induced increases in cardiorespiratory fitness did not correlate with change in the T1w/T2w signal. Together, our findings suggest that white matter regions that are vulnerable to aging retain some degree of plasticity that can be induced by aerobic exercise training. In addition, we provided evidence that the T1w/T2w signal may be a useful and broadly accessible measure for studying short-term within-person plasticity and deterioration in the adult human white matter.


Assuntos
Aptidão Cardiorrespiratória/fisiologia , Córtex Cerebral/fisiologia , Dança/fisiologia , Exercício Físico/fisiologia , Envelhecimento Saudável , Imageamento por Ressonância Magnética/métodos , Plasticidade Neuronal/fisiologia , Caminhada/fisiologia , Substância Branca/fisiologia , Acelerometria , Idoso , Anisotropia , Córtex Cerebral/diagnóstico por imagem , Cognição/fisiologia , Função Executiva/fisiologia , Teste de Esforço , Feminino , Humanos , Masculino , Memória Episódica , Testes de Estado Mental e Demência , Pessoa de Meia-Idade , Percepção/fisiologia
15.
Psychol Aging ; 35(8): 1154-1169, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32969693

RESUMO

Aerobic exercise and physical activity (PA) are known to benefit cognition in adulthood. However, a typical older adult spends most of the day sedentary or in light PA, behaviors that are typically poorly captured by questionnaires. To better understand the associations between time spent in different intensities of lifestyle PA and cognition, we measured average time spent daily in sedentariness, light, and moderate to vigorous PA using hip-worn sensors (ActiGraph accelerometers). We studied baseline data from 228 cognitively normal adults (Age 60-80) who took part in a clinical trial (clinical study identifier: NCT01472744). Fluid (processing speed, memory, and reasoning) and crystallized abilities (vocabulary knowledge) were assessed with the Virginia Cognitive Aging Battery. Adjusting for age, sex, and several modifiable socioeconomic, physical and functional health factors, time spent daily in moderate to vigorous PA was positively related with fluid abilities (perceptual speed and reasoning). Furthermore, we found that those spending more time sedentary performed better on vocabulary knowledge and reasoning tasks. In contrast, time spent in light PA was not related to either fluid or crystallized abilities. Our results add to the previous literature by providing the first sensor-based evidence that crystallized and fluid abilities in older age may be associated with engagement in different intensities of daily activity. Moreover, our findings suggest that the behavior of moderate to vigorous PA is at least as important in relation to cognition as the desirable long-term physiological effects of higher intensity PA and exercise. (PsycInfo Database Record (c) 2020 APA, all rights reserved).


Assuntos
Envelhecimento/fisiologia , Cognição/fisiologia , Exercício Físico/fisiologia , Comportamento Sedentário , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários
16.
Hum Brain Mapp ; 41(18): 5282-5300, 2020 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-32931076

RESUMO

Standard anatomical atlases are common in neuroimaging because they facilitate data analyses and comparisons across subjects and studies. The purpose of this study was to develop a standardized human brain atlas based on the physical mechanical properties (i.e., tissue viscoelasticity) of brain tissue using magnetic resonance elastography (MRE). MRE is a phase contrast-based MRI method that quantifies tissue viscoelasticity noninvasively and in vivo thus providing a macroscopic representation of the microstructural constituents of soft biological tissue. The development of standardized brain MRE atlases are therefore beneficial for comparing neural tissue integrity across populations. Data from a large number of healthy, young adults from multiple studies collected using common MRE acquisition and analysis protocols were assembled (N = 134; 78F/ 56 M; 18-35 years). Nonlinear image registration methods were applied to normalize viscoelastic property maps (shear stiffness, µ, and damping ratio, ξ) to the MNI152 standard structural template within the spatial coordinates of the ICBM-152. We find that average MRE brain templates contain emerging and symmetrized anatomical detail. Leveraging the substantial amount of data assembled, we illustrate that subcortical gray matter structures, white matter tracts, and regions of the cerebral cortex exhibit differing mechanical characteristics. Moreover, we report sex differences in viscoelasticity for specific neuroanatomical structures, which has implications for understanding patterns of individual differences in health and disease. These atlases provide reference values for clinical investigations as well as novel biophysical signatures of neuroanatomy. The templates are made openly available (github.com/mechneurolab/mre134) to foster collaboration across research institutions and to support robust cross-center comparisons.


Assuntos
Atlas como Assunto , Córtex Cerebral , Técnicas de Imagem por Elasticidade , Substância Cinzenta , Imageamento por Ressonância Magnética , Substância Branca , Adolescente , Adulto , Córtex Cerebral/anatomia & histologia , Córtex Cerebral/diagnóstico por imagem , Elasticidade , Técnicas de Imagem por Elasticidade/métodos , Feminino , Substância Cinzenta/anatomia & histologia , Substância Cinzenta/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Viscosidade , Substância Branca/anatomia & histologia , Substância Branca/diagnóstico por imagem , Adulto Jovem
18.
Front Hum Neurosci ; 14: 266, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32765239

RESUMO

Our jobs can provide intellectually and socially enriched environments but also be the source of major psychological and physical stressors. As the average full-time worker spends >8 h at work per weekday and remains in the workforce for about 40 years, occupational experiences must be important factors in cognitive and brain aging. Therefore, we studied whether occupational complexity and stress are associated with hippocampal volume and cognitive ability in 99 cognitively normal older adults. We estimated occupational complexity, physical stress, and psychological stress using the Work Design Questionnaire (Morgeson and Humphrey, 2006), Quantitative Workload Inventory and Interpersonal Conflict at Work Scale (Spector and Jex, 1998). We found that physical stress, comprising physical demands and work conditions, was associated with smaller hippocampal volume and poorer memory performance. These associations were independent of age, gender, brain size, socioeconomic factors (education, income, and job title), duration of the job, employment status, leisure physical activity and general stress. This suggests that physical demands at work and leisure physical activity may have largely independent and opposite effects on brain and cognitive health. Our findings highlight the importance of considering midlife occupational experiences, such as work physical stress, in understanding individual trajectories of cognitive and brain aging.

19.
Neurobiol Aging ; 84: 200-207, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31500910

RESUMO

Decline in fluid abilities in normal aging is associated with increased white matter lesions, measured on T1-weighted images as white matter signal abnormalities (WMSAs). WMSAs are particularly evident in hypertensive older adults, suggesting vascular involvement. However, because hypertension is assessed systemically, the specific role of cerebral arterial stiffening in WMSAs has yet to be demonstrated. In 93 cognitively normal adults (aged 18-87 years), we used a novel method to measure cerebral arterial elasticity (pulse relaxation function [PReFx]) with diffuse optical tomography (pulse-DOT) and investigated its association with WMSAs, age, and cognition. PReFx was associated with WMSAs, with older adults with low PReFx showing the greatest WMSA burden. PReFx in brain regions perfused by the middle cerebral artery showed the largest associations with WMSAs and partially mediated the relationship between age and WMSAs. Finally, WMSAs partially mediated the relationship between PReFx and fluid but not crystallized abilities scores. Taken together, these findings suggest that loss of cerebral arterial elasticity is associated with cerebral white matter lesions and age-related cognitive decline.


Assuntos
Artérias Cerebrais/patologia , Cognição , Envelhecimento Saudável/fisiologia , Rigidez Vascular , Substância Branca/fisiopatologia , Humanos
20.
J Appl Physiol (1985) ; 126(1): 77-87, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30382806

RESUMO

There is growing evidence that aerobic exercise protects against age-related cognitive decline and that cardiorespiratory fitness is an important factor for these benefits. Studies also suggest that combining physical activity with cognitive enrichment is beneficial. We further examine these predictions by comparing effects of a nutritional supplement promoting exercise capacity to a lower-intensity activity with cognitive enrichment on functional network and cognitive outcomes that otherwise decline with aging. Inactive healthy older adults were randomized to one of four groups including a low-intensity activity with complex cognitive demands (dancing), walking, walking+supplement, or an active control. Results showed that walking+supplement increased salience network functional connectivity (FC), with less training benefit for default mode network FC. Although cognitive performance did not increase for any training group, participants in the walking+supplement group who were on medication that boosted key neurotransmitters (e.g., selective serotonin reuptake inhibitors) showed improved processing speed. Overall, this study provides new insight into how to boost the protective effects of exercise on brain systems that otherwise deteriorate with aging. NEW & NOTEWORTHY Aerobic exercise effects on brain networks that otherwise decline with aging can be boosted with a nutritional supplement including beta-alanine. Beta-alanine supplementation could enhance the extent to which aerobic adaptations benefit the brain. In contrast, cognitive enrichment with low-intensity physical activity through dance did not affect functional networks. Medications that modulate neurotransmitters affected by aging (e.g., selective serotonin reuptake inhibitors) may modify effects of exercise on cognition.


Assuntos
Encéfalo/fisiologia , Cognição/fisiologia , Disfunção Cognitiva/prevenção & controle , Suplementos Nutricionais , Exercício Físico/fisiologia , Idoso , Aptidão Cardiorrespiratória , Dança , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino
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