Are Older Adults Who Volunteer to Participate in an Exercise Study Fitter and Healthier Than Nonvolunteers? The Participation Bias of the Study population

Participation bias in exercise studies is poorly understood among older adults. This study was aimed at looking into whether older persons who volunteer to participate in an exercise study differ from nonvolunteers. Methods: A self-reported questionnaire on physical activity and general health was mailed out to 1000 persons, aged 60 or over, who were covered by the medical insurance of the French National Education System. Among them, 535 answered it and sent it back. Two hundred and thirty-three persons (age 69.7 +/- 7.6, 65.7% women) said they would volunteer to participate in an exercise study and 270 (age 71.7 +/- 8.8, 62.2% women) did not. Results: Volunteers were younger and more educated than nonvolunteers, but they did not differ in sex. They had less physical function decline and higher volumes of physical activity than nonvolunteers. Compared with volunteers, nonvolunteers had a worse self-reported health and suffered more frequently from chronic pain. Multiple logistic regressions showed that good self-reported health, absence of chronic pain, and lower levels of physical function decline were associated with volunteering to participate in an exercise study. Conclusions: Volunteers were fitter and healthier than nonvolunteers. Therefore, caution must be taken when generalizing the results of exercise intervention studies

Le processus incapacitant au cours du vieillissement : rôle de l’exercice/activité physique

Le vieillissement est un phénomène d’importance croissante dans les sociétés actuelles. Bien que le rôle exercé par la pratique d’exercice/activité physique sur le maintien d’une capacité physique fonctionnelle optimale durant le vieillissement soit bien établi, l’inactivité physique est encore un comportement largement présent chez les personnes âgées, ce qui facilite le développement du processus incapacitant. Le but de cette revue de synthèse est d’exposer la chaîne de déclins physiologiques et fonctionnels au cours du vieillissement. Cette étude vise aussi à élucider le rôle exercé par la pratique d’exercice/activité physique afin d’empêcher ou retarder le début de tels déclins, et de renverser ou diminuer leur impact négatif sur des individus qui vieillissent. Ce travail explore l’influence des principales composantes du processus incapacitant (fragilité, limitation physique fonctionnelle, dépendance), et de la pratique d’exercice/activité physique sur la capacité physique fonctionnelle. Concernant le rapport « exercice/activité physique – processus incapacitant », certaines incohérences apparaissent parmi les études, ce qui réduit la possibilité de comparaison entre elles, et limite les conclusions. La définition du concept de fragilité, ainsi que la façon de mesurer les variables exercice/activité physique et fragilité constituent une des principales incohérences parmi ces études. Malgré cela, il ressort de ces études que la pratique régulière d’exercice/activité physique réduit des déclins liés à l’âge, tant sur le plan physiologique que sur celui de la capacité physique fonctionnelle. La pratique régulière d’exercice/activité physique contribue ainsi au maintien de l’indépendance des personnes âgées, à travers une minimisation des effets négatifs du processus incapacitant.Aging is a phenomenon of increased importance in contemporaneous societies. Although it is well established that physical exercise/activity contributes to maintain functional fitness at optimal levels, physical inactivity is a largely prevalent behaviour among elderly people, thus facilitating the disablement process. The purpose of this review is to study physiological and functional declines during aging. This article also tries to clarify the role played by physical exercise/activity in avoiding or delaying those declines, and in reverting or diminishing their negative impacts on older adults’ health. The influences of both disablement process main components (frailty, disability, and dependence) and of physical exercise/activity on functional fitness are examined. Concerning the relationships between physical exercise/activity and disablement process, some inconsistencies arise among articles, making difficult to compare them and to draw conclusions. The definitions of frailty, as well as the ways to measure physical exercise/activity, constitute the main inconsistencies among studies. However, most of the researches show that a regular practice of physical exercise/activity decreases the age-related declines in both physiological status and functional fitness. Then, exercising regularly can contribute to maintain independence in older adults by reducing the negative effects of the disablement process

MRI Findings in 77 Children with Non-Syndromic Autistic Disorder

International audienceBACKGROUND: The clinical relevance of MR scanning in children with autism is still an open question and must be considered in light of the evolution of this technology. MRI was judged to be of insufficient value to be included in the standard clinical evaluation of autism according to the guidelines of the American Academy of Neurology and Child Neurology Society in 2000. However, this statement was based on results obtained from small samples of patients and, more importantly, included mostly insufficient MRI sequences. Our main objective was to evaluate the prevalence of brain abnormalities in a large group of children with a non-syndromic autistic disorder (AD) using T1, T2 and FLAIR MRI sequences. METHODOLOGY: MRI inspection of 77 children and adolescents with non-syndromic AD (mean age 7.4+/-3.6) was performed. All met the DSM-IV and ADI -R criteria for autism. Based on recommended clinical and biological screenings, we excluded patients with infectious, metabolic or genetic diseases, seizures or any other neurological symptoms. Identical MRI inspections of 77 children (mean age 7.0+/-4.2) without AD, developmental or neurological disorders were also performed. All MRIs were acquired with a 1.5-T Signa GE (3-D T1-FSPGR, T2, FLAIR coronal and axial sequences). Two neuroradiologists independently inspected cortical and sub-cortical regions. MRIs were reported to be normal, abnormal or uninterpretable. PRINCIPAL FINDINGS: MRIs were judged as uninterpretable in 10% (8/77) of the cases. In 48% of the children (33/69 patients), abnormalities were reported. Three predominant abnormalities were observed, including white matter signal abnormalities (19/69), major dilated Virchow-Robin spaces (12/69) and temporal lobe abnormalities (20/69). In all, 52% of the MRIs were interpreted as normal (36/69 patients). CONCLUSIONS: An unexpectedly high rate of MRI abnormalities was found in the first large series of clinical MRI investigations in non-syndromic autism. These results could contribute to further etiopathogenetic research into autism

Cross-sectional Associations of Fatigue with Cerebral β-Amyloid in Older Adults at Risk of Dementia

Fatigue is a common symptom in the elderly and has also been associated with impaired cognition in older adults. Hence, we sought to explore the cross-sectional relationship between fatigue and cerebral \u3b2-amyloid (A\u3b2) in 269 elderly individuals reporting subjective memory complaints from the Multidomain Alzheimer Preventive Trial. Standard uptake value ratios (SUVRs) were generated by [18F] florbetapir positron emission tomography (PET) using the cerebellum as a reference. Cortical-to-cerebellar SUVRs (cortical-SUVRs) were obtained using the mean signal from the frontal cortex, temporal cortex, parietal cortex, precuneus, anterior cingulate, and posterior cingulate. Other brain regions independently assessed were the anterior cingulate, anterior putamen, caudate, hippocampus, medial orbitofrontal cortex, occipital cortex, parietal cortex, pons, posterior cingulate, posterior putamen, precuneus, semioval center, and temporal cortex. Fatigue was defined according to two questions retrieved from the Center for Epidemiological Studies-Depression scale. Chronic fatigue was defined as meeting fatigue criteria at two consecutive clinical visits 6 months apart between study baseline and 1 year (visits were performed at baseline, 6 months and 1 year then annually). Cross-sectional associations between fatigue variables and cerebral A\u3b2 were explored using fully adjusted multiple linear regression models. We found no statistically significant cross-sectional associations between fatigue assessed at the clinical visit closest to PET and A\u3b2 in any brain region. Similarly, chronic fatigue was not significantly associated with A\u3b2 load. Sensitivity analysis in subjects with a Clinical Dementia Rating of 0.5 showed that fatigue reported at the clinical visit closest to PET was, however, weakly associated with increased A\u3b2 in the hippocampus (B-coefficient: 0.07, 95% CI: 0.01, 0.12, p\u2009=\u20090.016). These preliminary results suggest that fatigue might be associated with A\u3b2 in brain regions associated with Alzheimer's disease in subjects in the early stages of disease

How Past and Present Influence the Foraging of Clonal Plants?

Clonal plants spreading horizontally and forming a network structure of ramets exhibit complex growth patterns to maximize resource uptake from the environment. They respond to spatial heterogeneity by changing their internode length or branching frequency. Ramets definitively root in the soil but stay interconnected for a varying period of time thus allowing an exchange of spatial and temporal information. We quantified the foraging response of clonal plants depending on the local soil quality sampled by the rooting ramet (i.e. the present information) and the resource variability sampled by the older ramets (i.e. the past information). We demonstrated that two related species, Potentilla reptans and P. anserina, responded similarly to the local quality of their environment by decreasing their internode length in response to nutrient-rich soil. Only P. reptans responded to resource variability by decreasing its internode length. In both species, the experience acquired by older ramets influenced the plastic response of new rooted ramets: the internode length between ramets depended not only on the soil quality locally sampled but also on the soil quality previously sampled by older ramets. We quantified the effect of the information perceived at different time and space on the foraging behavior of clonal plants by showing a non-linear response of the ramet rooting in the soil of a given quality. These data suggest that the decision to grow a stolon or to root a ramet at a given distance from the older ramet results from the integration of the past and present information about the richness and the variability of the environment

Le processus incapacitant au cours du vieillissement : rôle de l'exercice/activité physique.

Aging is a phenomenon of increased importance in contemporaneous societies. Although it is well established that physical exercise/activity contributes to maintain functional fitness at optimal levels, physical inactivity is a largely prevalent behaviour among elderly people, thus facilitating the disablement process. The purpose of this review is to study physiological and functional declines during aging. This article also tries to clarify the role played by physical exercise/activity in avoiding or delaying those declines, and in reverting or diminishing their negative impacts on older adults' health. The influences of both disablement process main components (frailty, disability, and dependence) and of physical exercise/activity on functional fitness are examined. Concerning the relationships between physical exercise/activity and disablement process, some inconsistencies arise among articles, making difficult to compare them and to draw conclusions. The definitions of frailty, as well as the ways to measure physical exercise/activity, constitute the main inconsistencies among studies. However, most of the researches show that a regular practice of physical exercise/activity decreases the age-related declines in both physiological status and functional fitness. Then, exercising regularly can contribute to maintain independence in older adults by reducing the negative effects of the disablement process.Le vieillissement est un phénomène d'importance croissante dans les sociétés actuelles. Bien que le rôle exercé par la pratique d'exercice/activité physique sur le maintien d'une capacité physique fonctionnelle optimale durant le vieillissement soit bien établi, l'inactivité physique est encore un comportement largement présent chez les personnes âgées, ce qui facilite le développement du processus incapacitant. Le but de cette revue de synthèse est d'exposer la chaîne de déclins physiologiques et fonctionnels au cours du vieillissement. Cette étude vise aussi à élucider le rôle exercé par la pratique d'exercice/activité physique afin d'empêcher ou retarder le début de tels déclins, et de renverser ou diminuer leur impact négatif sur des individus qui vieillissent. Ce travail explore l'influence des principales composantes du processus incapacitant (fragilité, limitation physique fonctionnelle, dépendance), et de la pratique d'exercice/activité physique sur la capacité physique fonctionnelle. Concernant le rapport " exercice/activité physique - processus incapacitant ", certaines incohérences apparaissent parmi les études, ce qui réduit la possibilité de comparaison entre elles, et limite les conclusions. La définition du concept de fragilité, ainsi que la façon de mesurer les variables exercice/activité physique et fragilité constituent une des principales incohérences parmi ces études. Malgré cela, il ressort de ces études que la pratique régulière d'exercice/activité physique réduit des déclins liés à l'âge, tant sur le plan physiologique que sur celui de la capacité physique fonctionnelle. La pratique régulière d'exercice/activité physique contribue ainsi au maintien de l'indépendance des personnes âgées, à travers une minimisation des effets négatifs du processus incapacitant

Activités instrumentales physiques de la vie quotidienne chez les personnes âgées : validation d'une échelle

Une recueil d'exposés présentés en Ateliers pédagogique

Il était une fois l'écran : espace collaboratif de ressources pour l'apprentissage numérique

la présentation est accessible dans l'outil Geniall

Exercice et activité physique chez les personnes âgées lors du "processus de dégénérescence physique"

Introduction. Le vieillissement est caractérisé par des déclins de réserves physiologiques dedivers systèmes de l organisme, ainsi que par des réductions au plan fonctionnel qui limitentla capacité des individus à exécuter certaines activités. Bien que cette détérioration physiquene puisse pas être empêchée, plusieurs facteurs interviennent pendant le vieillissement,influençant le début et la vitesse de progression de ces déclins. La pratique d exercice/activitéphysique semble constituer un moyen de retarder le de but de ces déclins, et de ralentir leurprogression. Malgré cela, le rôle de l exercice/activité physique sur certains aspects de cettedétérioration physique n est pas encore bien établi. Le but de ce travail est d étudier le rôlejoué par l exercice/activité physique sur la détérioration physique chez des personnes âgées de60 ans ou plus, ainsi que de rechercher des aspects déterminants de l adhésion à la pratiqued exercice/activité physique dans cette population.Matériel et méthode. Afin de guider notre travail, nous avons proposé un modèle théoriqueappelé processus de dégénérescence physique . Ce modèle, qui constitue une extensiond un autre modèle déjà existant, est adapté à la population âgée et a intégré dans sa structurele concept de fragilité. Nous avons utilisé plusieurs approches complémentaires. Au moyend une étude pilote (n = 54), nous avons examiné des propriétés métrologiques de certainsoutils de mesure qui sont utilisés tout au long de notre travail. Ensuite nous avons réalisé uneenquête par courrier (n = 1000, dont 535 individus ont répondu), puis le suivi sur un an decette enquête (n = 535, dont 384 individus ont répondu) ; ces recherches nous ont permisd établir des liens transversaux et des associations de prédiction entre exercice/activitéphysique et certains aspects de la détérioration physique. Au moyen d une recherched intervention (n = 37), nous avons testé l impact d un programme de 22 semaines d exercicephysique (marche nordique) sur des déclins physiques. Enfin, nous avons réalisé une étudequalitative (n = 21) afin de mieux connaître les facteurs de motivation et les obstacles pourparticiper à un programme d exercice physique chez des personnes ayant un degré de déclinphysique important.Résultats. Les outils de mesure testés lors de l étude pilote ont présenté des propriétésmétrologiques d un niveau satisfaisant à bon. L enquête et son suivi sur un an ont montré quela pratique d exercice/activité physique était associée à plusieurs aspects du processus dedétérioration physique : le niveau d activité physique a été négativement associé à la présencede co-morbidité et de déclins physiques fonctionnels. La pratique d un exercice physique(marche nordique) a amélioré certains aspects de la condition physique des participants (e.g.,équilibre dynamique, vitesse de marche maximale). D autre part, les déclins physiques6fonctionnels, à partir d associations négatives, ont prédit le niveau d activité physique au boutd un an ; ces déclins ont aussi modulé l association entre sexe et niveau d activité physique aubout d un an. A partir de l étude qualitative, nous avons pu observer que la perception qu ontles individus de leur propre condition physique, l intérêt que leur procure un exercicephysique, ainsi que les incitations de leur médecin jouent un rôle crucial dans l adoption d unstyle de vie physiquement actif.Conclusion. Ce travail contribue aux connaissances dans le domaine de la pratiqued exercice/activité physique chez des personnes âgées. L utilisation de plusieurs approchesméthodologiques a permis d aborder la relation exercice/activitéphysique détériorationphysique sous plusieurs angles différents ; elle renforce la portée de ce travail. Les étudescontenues dans ce manuscrit ont montré que la pratique d exercice/activité physique joue unrôle de grande importance dans la prévention de la détérioration physique qui survientpendant le vieillissement, et ce, même dans une courte période de suivi. A son tour ladétérioration physique est un aspect déterminant dans l adoption ou non d un style de viephysiquement actif. Une des originalités de notre recherche a consisté à choisir pour cetteétude une population partiellement constituée de personnes âgées présentant déjà des déclinsphysiques fonctionnels, une population souvent négligée dans la littérature. Les étudesprésentées dans ce manuscrit contribuent activement au débat, toujours actuel, surl importance d un style de vie physiquement actif au cours du vieillissement, ainsi qu à laconnaissance des aspects qui peuvent influencer l adoption et le maintien d un style de viephysiquement actif des individus pendant le vieillissement.The aging process is characterised by declines in physiological reserves inseveral organic systems, as well as in physical function. These declines are unavoidable, andreduce individuals ability to execute daily activities. Several factors interact to determine thedevelopment and progression of these declines. Physical activity and exercise seem toconstitute important tools for delaying the development and progression of physicaldeteriorations. However, certain aspects of the relationship between physical activity/exerciseand physical deterioration during aging are not well-established. The purpose of this workwere (1) to study the role played by physical activity and exercise on physiological andfunctional declines in persons 60 years-old or over, and (2) to investigate the aspects thatdetermine adherence to exercise/physical activity in this population.Methods. To guide our research, we proposed a theoretical framework labelled processusde dégénérescence physique . This framework contitutes an extension of another theoreticalmodel, and it is adapted to older adult populations. Furthermore, our framework incorporatedthe concept of frailty. We used different and complementary research designs. A pilot study(n = 54) was developed to examine psychometric properties of certain assessment tools. Afterthat, we developed a postal survey (n = 1000, from which 535 replied to this research) with ayear follow-up (n = 535, from which 384 replied to this research) ; this survey and its followupallowed us to study cross-sectional and predictive relatioships between physicalactivity/exercise and the components of physical deteriorations. An intervention study (n =37) was carried out to investigate effects of a 22-week exercise program (nordic walking) onphysical deterioration. Finally, we led a qualitative study (n = 21) to improve currentknowledge on motivators and obstacles for enrollment in an exercise program amongfunctionally limited older adults.Results. The assessment tools examined in our pilot study had satisfactory to goodpsychometric properties. The postal survey (including the follow-up) showed that physicalactivity and exercise were associated to physical deteriorations. The level of physical activitywas negatively associated with co-morbidity and with functional declines. Exercise practice(nordic walking) improved certain aspects of participants physical fitness (e.g., dynamicbalance, fastest walking speed). Functional declines were directly associated to the level ofphysical activity through negative associations, and they mediated the relationship betweensex and the level of physical activity a year later. Our qualitative research highlighted theimportance of individuals perception about their physical status, interest in exercising, and8the role of physician s incentive for increasing individual s intention to adopt a physicallyactive lifestyle.Conclusion. This work improves current understanding in the field of physicalactivity/exercise in the elderly. The different research designs used herein allowed us toinvestigate physical activity/exercise physical changes relationship through severalperspectives, which increase the importance of this work. The studies developed in thismanuscript showed that physical activity and exercise play an important role in preventingphysical deterioration during aging, even in a short-term follow-up. Physical deterioration is adeterminant of a physically active lifestyle. An original aspect of our research concerned thestudy sample, which was partially composed of physically limited older adults. Thispopulation is frequently neglected in research on physical activity. The studies we presentedin this manuscript contribute actively to the current debate about the importance of aphysically active lifestyle during aging. Moreover, they contribute to improve understandingabout factors associated to adoption or maintenance of a physically active lifestyle amongolder adults.AIX-MARSEILLE2-Bib.electronique (130559901) / SudocSudocFranceF