To determine the relationship between the amount and intensity of physical activity performed by older adults in North America (United States and Canada) and their depression and anxiety symptoms ...while currently under social distancing guidelines (SDG) for the COVID-19 pandemic.
Descriptive cross-sectional study.
Online survey conducted between April 9 and April 30, 2020, during the COVD-19 pandemic.
About 1,046 older adults over the age of 50 who live in North America.
Participants were asked about their basic demographic information, current health status, and the impact of the current SDG on their subjective state of mental health. Participants completed the Physical Activity Scale for the Elderly, to determine the amount and intensity of physical activity performed, as well as both the Geriatric Depression Scale and Geriatric Anxiety Scale, to ascertain the extent of their depression and anxiety-like symptoms.
Ninety-seven percent of participants indicated that they adhered to current SDG "Most of the time" or "Strictly." Participants who performed greater levels of physical activity experienced lower levels of depression-like symptoms when age, sex, and education were accounted for; however, no relationship between physical activity and anxiety-like symptoms was found. A hierarchical regression analysis that incorporated the intensity of physical activity performed (light, moderate, and vigorous) in the model indicated that greater light and strenuous activity, but not moderate, predicted lower depression-like symptoms.
These results suggest that performing even light physical activity during the COVID-19 pandemic may help alleviate some of the negative mental health impacts that older adults may be experiencing while isolated and adhering to SDG during the COVID-19 pandemic.
Traumatic brain injury (TBI) is a serious public health problem accounting for 1.4 million emergency room visits by US citizens each year. Although TBI has been traditionally considered an acute ...injury, chronic symptoms reminiscent of neurodegenerative disorders have now been recognized. These progressive neurodegenerative-like symptoms manifest as impaired motor and cognitive skills, as well as stress, anxiety, and mood affective behavioral alterations. TBI, characterized by external bumps or blows to the head exceeding the brain's protective capacity, causes physical damage to the central nervous system with accompanying neurological dysfunctions. The primary impact results in direct neural cell loss predominantly exhibiting necrotic death, which is then followed by a wave of secondary injury cascades including excitotoxicity, oxidative stress, mitochondrial dysfunction, blood-brain barrier disruption, and inflammation. All these processes exacerbate the damage, worsen the clinical outcomes, and persist as an evolving pathological hallmark of what we now describe as chronic TBI. Neuroinflammation in the acute stage of TBI mobilizes immune cells, astrocytes, cytokines, and chemokines toward the site of injury to mount an antiinflammatory response against brain damage; however, in the chronic stage, excess activation of these inflammatory elements contributes to an "inflamed" brain microenvironment that principally contributes to secondary cell death in TBI. Modulating these inflammatory cells by changing their phenotype from proinflammatory to antiinflammatory would likely promote therapeutic effects on TBI. Because neuroinflammation occurs at acute and chronic stages after the primary insult in TBI, a treatment targeting neuroinflammation may have a wider therapeutic window for TBI. To this end, a better understanding of TBI etiology and clinical manifestations, especially the pathological presentation of chronic TBI with neuroinflammation as a major component, will advance our knowledge on inflammation-based disease mechanisms and treatments.
•Regular participation in exercise and higher fitness modulate functional connectivity of the brain.•Exercise-related changes in functional connectivity corresponds to cognitive and motor ...performances improvements.•Greater physical activity levels and fitness are associated with better motor and cognitive function, mediated by enhanced white matter microstructural integrity.
The number of studies investigating exercise and cardiorespiratory fitness (CRF)-related changes in the functional and structural organization of brain networks continues to rise. Functional and structural connectivity are critical biomarkers for brain health and many exercise-related benefits on the brain are better represented by network dynamics. Here, we reviewed the neuroimaging literature to better understand how exercise or CRF may facilitate and maintain the efficiency and integrity of functional and structural aspects of brain networks in both younger and older adults. Converging evidence suggests that increased exercise performance and CRF modulate functional connectivity of the brain in a way that corresponds to behavioral changes such as cognitive and motor performance improvements. Similarly, greater physical activity levels and CRF are associated with better cognitive and motor function, which may be brought about by enhanced structural network integrity. This review will provide a comprehensive understanding of trends in exercise-network studies as well as future directions based on the gaps in knowledge that are currently present in the literature.
In addition to skeletal muscle dysfunction, cancer cachexia is a systemic disease involving remodeling of nonmuscle organs such as adipose and liver. Impairment of mitochondrial function is ...associated with multiple chronic diseases. The tissue-specific control of mitochondrial function in cancer cachexia is not well defined. This study determined mitochondrial respiratory capacity and coupling control of skeletal muscle, white adipose tissue (WAT), and liver in colon-26 (C26) tumor-induced cachexia. Tissues were collected from PBS-injected weight-stable mice, C26 weight-stable mice and C26 mice with moderate (10% weight loss) and severe cachexia (20% weight loss). The respiratory control ratio (RCR) an index of oxidative phosphorylation (OXPHOS) coupling efficiency was low in WAT during the induction of cachexia because of high nonphosphorylating LEAK respiration. Liver RCR was low in C26 weight-stable and moderately cachexic mice because of reduced OXPHOS. Liver RCR was further reduced with severe cachexia, where Ant2 but not Ucp2 expression was increased. Ant2 was inversely correlated with RCR in the liver (
= -0.547,
< 0.01). Liver cardiolipin increased in moderate and severe cachexia, suggesting this early event may also contribute to mitochondrial uncoupling. Impaired skeletal muscle mitochondrial respiration occurred predominantly in severe cachexia, at complex I. These findings suggest that mitochondrial function is subject to tissue-specific control during cancer cachexia, whereby remodeling in WAT and liver arise early and may contribute to altered energy balance, followed by impaired skeletal muscle respiration. We highlight an under-recognized role of liver and WAT mitochondrial function in cancer cachexia and suggest mitochondrial function of multiple tissues to be therapeutic targets.
Hepatic mitochondrial function loss is associated with cancer cachexia pathology in vivo. Here, we examined if hepatic mitochondrial defects observed in vivo in the cachexic liver also recapitulate ...during the in vitro treatment of mouse hepatocytes with tumor conditioned media. In vitro experiments were combined with proteome-wide expression analysis of cachexic liver tissue curated for mitochondrial dynamics and quality control proteins, to determine the fidelity of hepatic mitochondrial maladaptation in cancer cachexia pathology. AML12 hepatocytes were exposed to colon-26 (C26) and Lewis lung carcinoma (LLC) conditioned media for 6–72 h and assayed for cell viability, membrane potential, respiratory function, H
2
O
2
production, total ROS/RNS, and mitochondrial dynamics and quality control proteins by immunoblotting. Liver tissue from cachexic C26 mice was analyzed by TMT-based quantitative proteomics for in vivo comparison. Cell viability, membrane potential, H
2
O
2
production, total ROS/RNS, and respiration were decreased 48–72 h after exposure to C26 and/or LLC. Protein expression of treated hepatocytes and cachexic liver tissue showed altered mitochondrial dynamics and quality control, in a manner that suggests limited fusion and content mixing, but also impaired ability to fragment and clear damaged mitochondria. Two strategies to maintain mitochondrial health, therefore, may not be functioning sufficiently in the cachexic liver. Together these findings imply adverse effects of C26 and LLC exposure on hepatocyte health, due to impaired mitochondrial function and remodeling. Exposure of mouse hepatocytes to tumor conditioned media models aspects of cachexic liver mitochondria dysfunction in vivo and validates the importance of hepatic mitochondrial maladaptation in cancer cachexia pathology.
Abstract Skeletal muscle atrophy and dysfunction commonly accompany cardiovascular diseases such as peripheral arterial disease and may be partially attributable to systemic inflammation. We sought ...to determine whether acute systemic inflammation in a model of hindlimb ischaemia (HLI) could affect skeletal muscle macrophage infiltration, fibre size, or capillarization, independent of the ischaemia. Eight‐week‐old C57BL/6 male mice underwent either Sham or HLI surgery, and were killed 1, 3, or 7 days post‐surgery. Circulating inflammatory cytokine concentrations were measured, as well as immune cell infiltration and morphology of skeletal muscle from both limbs of HLI and Sham mice. In HLI compared with Sham mice at day 1, plasma interleukin‐1β levels were 216% higher (0.48 ± 0.10 vs. 0.15 ± 0.01 pg/μL, P = 0.005) and decreased by day 3. This was followed by increased macrophage presence in muscle from both ischaemic and non‐ischaemic limbs of HLI mice by day 7 (7.3‐ and 2.3‐fold greater than Sham, respectively, P < 0.0001). In HLI mice, muscle from the ischaemic limb had 21% lower fibre cross‐sectional area than the non‐ischaemic limb (724 ± 28 vs. 916 ± 46 μm 2 , P = 0.01), but the non‐ischaemic limb of HLI mice was no different from Sham. This shows that HLI induces acute systemic inflammation accompanied by immune infiltration in both ischaemic and remote skeletal muscle; however, this did not induce skeletal muscle atrophy in remote muscle within the 7‐day time course of this study. This effect of local skeletal muscle ischaemia on the inflammatory status of remote skeletal muscle may signal a priming of muscle for subsequent atrophy over a longer time course. Highlights What is the central question of this study? Does hindlimb ischaemia‐induced inflammation cause acute immune, inflammatory and morphological alterations in remote non‐ischaemic skeletal muscle? What is the main finding and its importance? Hindlimb ischaemia induced systemic inflammation with subsequent neutrophil and macrophage infiltration in both ischaemic and non‐ischaemic skeletal muscle; however, morphological changes did not occur in non‐ischaemic muscle within 7 days. These immune alterations may have functional implications that take longer than 7 days to manifest, and subsequent or prolonged systemic inflammation and immune infiltration of muscle could lead to morphological changes and functional decline.
The well-elucidated improvement of mood immediately after exercise in older adults presumably involves adaptations in emotion-processing brain networks. However, little is known about effects of ...acute exercise on appetitive and aversive emotion-related network recruitment in older adults. The purpose of this study was to determine the effect of acute exercise, compared to a seated rest control condition, on pleasant and unpleasant emotion-related regional activation in healthy older adults. Functional MRI data were acquired from 32 active older adults during blocked presentations of pleasant, neutral and unpleasant images from the International Affective Pictures System. fMRI data were collected after participants completed 30 min of moderate to vigorous intensity cycling or seated rest, performed in a counterbalanced order across separate days in a within-subject design. The findings suggest three ways that emotional processing in the brain may be different immediately after exercise (relative to immediately after rest): First, reduced demands on emotional regulation during pleasant emotional processing as indicated by lower precuneus activation for pleasant stimuli; second, reduced processing of negative emotional stimuli in visual association areas as indicated by lower activation for unpleasant stimuli in the bilateral fusiform and ITG; third, an increased recruitment in activation associated with regulating/inhibiting unpleasant emotional processing in the bilateral medial superior frontal gyrus (dorsomedial prefrontal cortex), angular gyri, supramarginal gyri, left cerebellar crus I/II and a portion of right dorsolateral prefrontal cortex. Overall, these findings support that acute exercise in active older adults alters activation in key emotional processing and regulating brain regions.
Ample evidence suggests exercise is beneficial for hippocampal function. Furthermore, a single session of aerobic exercise provides immediate benefits to mnemonic discrimination performance, a highly ...hippocampal-specific memory process, in healthy younger adults. However, it is unknown if a single session of aerobic exercise alters mnemonic discrimination in older adults, who generally exhibit greater hippocampal deterioration and deficits in mnemonic discrimination performance.
We conducted a within subject acute exercise study in 30 cognitively healthy and physically active older adults who underwent baseline testing and then completed two experimental visits in which they performed a mnemonic discrimination task before and after either 30 min of cycling exercise or 30 min of seated rest. Linear mixed-effects analyses were conducted in which condition order and age were controlled, time (pre vs. post) and condition (exercise vs. rest) were modeled as fixed effects, and subject as a random effect.
No significant time by condition interaction effect was found for object recognition (
= .254, η
=.01), while a significant reduction in interference was found for mnemonic discrimination performance following the exercise condition (
= .012, η
=.07). A post-intervention only analysis indicated that there was no difference between condition for object recognition (
= .186, η
=.06), but that participants had better mnemonic discrimination performance (
< .001, η
=.22) following the exercise.
Our results suggest a single session of moderate-intensity aerobic exercise may reduce interference and elicit better mnemonic discrimination performance in healthy older adults, suggesting benefits for hippocampal-specific memory function.
Biological aging is accompanied by a chronic pro-inflammatory state that may facilitate losses in hippocampal-dependent mnemonic discrimination. Aerobic exercise training promotes adaptations that ...include improved immune competency, higher cardiorespiratory fitness, and maintenance of hippocampal function. However, it is poorly understood whether, in active older adults, baseline immune cell profiles and cardiorespiratory fitness are possible mechanisms that facilitate the long-term benefits to hippocampal dependent mnemonic discrimination performance. This within-subjects study with counterbalanced conditions aimed to investigate whether baseline monocyte polarization and cardiorespiratory fitness influenced performance in the mnemonic similarity task (MST) and related Lure Discrimination Index (LDI) score after an acute bout of exercise. Twenty-one active older adults (M = 68 ± 5 yrs) underwent baseline testing in which blood samples were collected and cardiorespiratory fitness measured. Participants then returned and completed a seated rest or moderate intensity aerobic exercise condition in which the MST was proctored prior to and 5 min after each condition. A linear mixed effects model was used in which Participant ID was a random effect and Condition (rest v. exercise), Time (pre- v post-), and order were fixed main effects. Simple linear regression models were used to determine the variance accounted for by monocyte phenotypes and cardiorespiratory fitness for LDI scores post-condition. Post-rest LDI scores were significantly lower than post-exercise LDI scores (t(20) = −2.65, p < 0.02, d = −0.57). Intermediate monocytes were significant predictors of the change in pre- to post-exercise LDI scores (F(1, 19) = 6.03, p = 0.024, R2 = 0.24) and cardiorespiratory fitness was a significant predictor of the difference between post-condition LDI scores (F(1, 19) = 6.71, p = 0.018, R2 = 0.26). Our results suggest baseline cardiorespiratory fitness and intermediate monocytes may relate to the integrity of hippocampal-dependent mnemonic discrimination performance, and possibly the degree of responsiveness to aerobic exercise interventions.
•Aerobic exercise benefits mnemonic discrimination performance in older adults.•Lower fitness is associated with greater benefits LDI scores after acute exercise.•High counts of intermediate monocytes may blunt cognitive benefits of exercise.
Obesity with advancing age leads to increased health complications that are involved in various complex physiological processes. For example, inflammation is a critical cardiovascular disease risk ...factor that plays a role in the stages of atherosclerosis in both aging and obesity. Obesity can also induce profound changes to the neural circuitry that regulates food intake and energy homeostasis with advancing age. Here we discuss how obesity in older adults impacts inflammatory, cardiovascular, and neurobiological functions with an emphasis on how exercise mediates each topic. Although obesity is a reversible disorder through lifestyle changes, it is important to note that early interventions are crucial to prevent pathological changes seen in the aging obese population. Lifestyle modifications such as physical activity (including aerobic and resistance training) should be considered as a main intervention to minimize the synergistic effect of obesity on age-related conditions, such as cerebrovascular disease.
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