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

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

Assessment of plasma amyloid-β42/40 and cognitive decline among community-dwelling older adults

Importance: Plasma measurement of amyloid-β (Aβ) peptides has been associated with cognitive function, but evidence of its ability to identify cognitive decline is still scarce. Objective: To investigate the associations between plasma Aβ42/40 and cognitive decline over time among community-dwelling older adults with subjective memory concerns. Design, Setting, and Participants: This multicenter cohort study used data from volunteers in the 5-year study Multidomain Alzheimer Preventive Trial (MAPT). Participants were aged 70 years or older and observed for a median (interquartile range) of 3.9 (2.0-4.0) years. Recruitment of participants started in May 2008 and ended in February 2011. Follow-up ended in April 2016. Data analysis was conducted from April to October 2020. Exposure: Plasma Aβ42 and Aβ40 were measured at 12 months for 448 participants (92.8%) and at 24 months for the rest. The moment of Aβ assessment was defined as the baseline for this study. Main Outcomes and Measures: Cognitive function was assessed at 12, 24, 36, 48, and 60 months by a composite cognitive score based on 4 tests; Mini Mental State Examination (MMSE); Clinical Dementia Rating, sum of boxes; and Alzheimer Disease Cooperative Study-Activities of Daily Living. Mixed-effect linear regressions were performed. Results: A total of 483 participants (median [IQR] age, 76.0 [73.0-80.0]; 286 [59.2%] women) were analyzed. Of them, 161 (33.3%) were classified as low plasma Aβ42/40 (≤0.107). After adjusting for age, sex, education, body mass index, Geriatric Depression Scale score, apolipoprotein E ε4 genotype, and MAPT intervention groups, low plasma Aβ42/40 was associated with more pronounced decline in composite cognitive score (adjusted between-group mean difference: -0.20, 95% CI, -0.34 to -0.07; P = .004) and decline in MMSE score (adjusted between-group mean difference: -0.59; 95% CI, -1.07 to -0.11; P = .02) during the follow-up period compared with the group with an Aβ42/40 ratio greater than 0.107. Conclusions and Relevance: In this study, low plasma Aβ42/40 was associated with more pronounced decline in cognitive function (measured by multiple outcomes) over time. Findings suggest that plasma Aβ42/40 may be used to identify people at risk of cognitive decline, being an alternative to more complex and expensive measures, such as positron emission tomography imaging or cerebrospinal fluid measurement

Differences in stomatal and pollen grain dimensions and pollen viability between Paspalum rawitscheri populations

The objective of this study was to evaluate stomatal and pollen grain size and to estimate pollen viability of individuals from different populations of Paspalum rawitscheri (Parodi) Chase ex G.H. Rua & Valls. To analyze stomatal size, slides were made of the adaxial leaf epidermis using the epidermal impression method. The height and width of 100 stomata per population were analyzed. Pollen was obtained from inflorescences to evaluate pollen grain size and pollen viability. Pollen grains were stained with 2% acetic orcein, 2% acetic carmine, or Alexander’s reactive stain. Per population, 1600 grains of pollen were observed for viability, and 50 grains of pollen were measured. There were significant differences between populations in stomatal height and pollen grain height and width. The populations also differed in pollen viability, with the Santa Maria population showing the lowest viability. The differences in stomatal and pollen grain size suggest genetic variability in the evaluated populations. Moreover, low pollen viability in one population indicates that its decline may be related to low fertility. Keywords: Grass. Ploidy. Fertility. Threatened species

A seca e seus desdobramentos: reflexões a partir da realidade da Microrregião de Pau dos Ferros

The Northeast region has always been the region of drought, underdevelopment, the destituous man and several other stereotypes that enshrined the characterization of their human, economic and spatial configuration. The absence of water is a striking aspect, which in addition to flagellating the Northeastern region, is used by government representatives to adopt “solution to drought” speeches to acquire popular support. The objective of this work is to present the loss of importance of rural activities in the microregion of Pau dos Ferros/RN and to discuss the emergency measures adopted to alleviate water scarcity with emphasis in this municipality. Data were collected focusing on the variables Population and Gross Agricultural Domestic Product; data were collected at the Secretariat of Rural Development of Pau dos Ferros/RN city; and searches were carried out about the water issue of this municipality in online portals. Therefore, what was observed was the relative loss of participation of agricultural GDP in the composition of municipal GDP, reduction of the rural population in this microregion and the implementation of palliative actions to combat drought.A região Nordeste sempre foi vista como a região da seca, do subdesenvolvimento, do homem desamparado e de diversos outros estereótipos que consagraram a caracterização de sua configuração humana, econômica e espacial pelas outras regiões do país. A ausência de água é um aspecto marcante, que além de flagelar o nordestino, é utilizada como aporte político para muitos representantes governamentais adotarem discursos de “solução à seca” com a finalidade de adquirirem apoio popular. O objetivo deste trabalho é apresentar a perda de importância das atividades rurais na microrregião de Pau dos Ferros/RN e discutir as medidas emergenciais adotadas para amenizar a escassez de água com ênfase neste município. Para tanto, foi realizado levantamento de dados com foco nas variáveis População e Produto Interno Bruto Agropecuário, extraídos das bases de dados do IBGE; coletados dados na Secretaria de Desenvolvimento Rural de Pau dos Ferros/RN; e realizadas buscas acerca da questão hídrica deste município em portais online. Diante disso, o que se observou foi a relativa perda de participação do PIB agropecuário na composição do PIB Municipal, redução da população rural nessa microrregião e a implantação de ações paliativas de combate à seca

Avaliação das lectinas WGA e Con A como biomarcadoras de esquistossomose hepatoesplênica em biopsias humanas sem evidência do sistema ovo-granuloma

Introdução: Lesões do cólon são predominantes em pacientes com esquistossomose, entretanto alterações dos carboidratos no cólon com esquistossomose permanecem desconhecidas. Ligantes de lectinas permitem a identificação das mudanças no padrão dos carboidratos celulares. Métodos: Biópsias do cólon descendente e sigmóide dos pacientes foram submetidas a histoquímica com as lectinas WGA e Con A. Resultados: WGA marcou o estroma dos tecidos das células glandulares do cólon descendente e sigmóide com um padrão citoplasmático intenso e granular em espécimes com esquistossomose diferindo do controle normal e da Con A, a qual não reconheceu nenhum tecido estudado. Cólon sem esquistossomose não apresentou marcação. Conclusões: ligantes de WGA são diferentemente expressos em pacientes com esquistossomose hepatoesplênica sem evidência de sistema ovo-granuloma.Introduction: Colonic lesions are predominant in patients with schistosomiasis. However, carbohydrate alterations in colonic schistosomiasis remain unclear. Lectin-ligands allow us to identify changes in the saccharide patterns of cells. Methods: Biopsies of descending and rectosigmoid colon of patients were submitted to WGA and Con A lectin histochemistry. Results: WGA stained stroma and gland cells of descending colon and rectosigmoid tissues in a granular strong cytoplasmatic pattern in schistosomiasis specimens differing from normal control and Con A failing to recognize all samples analyzed. Conclusions: WGA ligands are expressed differently in patients with hepatosplenic schistosomiasis and no evidence of egg-granuloma system