Associations between dementia/mild cognitive impairment and cognitive performance and activity levels in youth
ABSTRACT To study the associations between dementia/mild cognitive impairment (MCI) and cognitive performance and activity levels in youth.
Retrospective cohort study.
Research volunteers living throughout the United States.
A total of 396 persons (mean age 75) who were graduates of the same high school in the mid-1940s.
Adolescent intelligence quotient (IQ) scores were gathered from archived student records, and activity levels were determined from yearbooks. A two-stage telephone screening procedure (Modified Telephone Interview for Cognitive Status or Informant Questionnaire on Cognitive Decline in the Elderly followed by Dementia Questionnaire) was used to determine adult cognitive status. Data were analyzed using logistic regression to model the risk of cognitive impairment (dementia/MCI) versus no cognitive impairment as a function of IQ and activity level, adjusting for sex and education.
High adolescent IQ and greater activity level were each independently associated with a lower risk for dementia/MCI (odds ratio (OR) for a 1-standard deviation increase in IQ=0.51, 95% confidence interval (CI)=0.32-0.79; OR for a unit increase in activity=0.32, 95% CI=0.12-0.84). No association was found between sex or education and adult cognitive status in this model.
High IQ and greater activity levels in youth reduce the risk for cognitive impairments in aging. The mechanism(s) underlying these associations are unknown, but intelligence may be a marker for cognitive/neurological "reserve," and involvement in activities may contribute to "reserve." Early neuropathology and ascertainment bias are also possible explanations for the observed associations.
- SourceAvailable from: Hyuma Makizako
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- "Frequency of attainment is included as an important factor for assessing life-space (Baker et al., 2003). A previous study indicated that greater activity levels in youth reduced the risk of cognitive impairments in aging, and that involvement in certain activities may contribute to cognitive ''reserve'' (Fritsch et al., 2005). In addition, an epidemiological study suggested that participation in cognitively stimulating leisure activity (e.g., attending a class, lecture, or public meeting; and participating in community, church, or social clubs) may attenuate the effects of brain lesion pathology on cognitive performance in older adults (Saczynski et al., 2008). "
ABSTRACT: This study sought to investigate the relationship between going outdoor daily and prefrontal cortex activation during execution of the VFT using near-infrared spectroscopy (NIRS) in community-dwelling older adults. Blood oxygenation changes in left and right prefrontal cortices were measured in twenty older adults (mean age 76.1±6.7 years) by NIRS during VFT performance. In this task, participants were required to pronounce as many nouns as possible beginning with the letters "Shi," "I," and "Re." Changes in oxygenated hemoglobin (oxy-Hb) levels during the VFT were compared between two groups defined by the frequency of going outdoors: daily or non-daily within a week. Participants in both groups exhibited significantly increased oxy-Hb levels in the left and right prefrontal cortices during the VFT compared to a resting baseline condition. After controlling for age and gender, there were significant group-by-condition interactions on oxy-Hb levels with less activation during the execution of the VFT over both cortices in the non-daily group (left: F=4.76, p=0.04; right: F=6.32, p=0.02). These findings indicate that going outdoors daily is associated with increased activation in the prefrontal cortices during VFT performance in community-dwelling older adults.Archives of gerontology and geriatrics 09/2012; 56(1). DOI:10.1016/j.archger.2012.08.017 · 1.53 Impact Factor
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ABSTRACT: Le vieillissement normal est associé à une réorganisation cérébrale qui peut être influencée par plusieurs facteurs. Des théories comme la réserve cognitive de Stern (2002) tentent d’expliquer les effets de ces différents facteurs. Certains, le niveau de scolarité par exemple, sont encore mal connus. Pourtant, le niveau de scolarité est connu pour avoir un impact sur les performances cognitives tout au long de la vie. Le but de ce mémoire est d’étudier les effets du niveau de scolarité sur l’oxygénation cérébrale de personnes âgées en santé lors d’une tâche d’évocation lexicale orthographique et sémantique. Chaque tâche est divisée selon un critère « plus productive » et « moins productive ». Les âgés faiblement scolarisés produisent moins de mots que les âgés fortement scolarisés. De plus, la différence de mots produits entre le critère plus productif et moins productif est plus grande pour la tâche sémantique que pour la tâche orthographique. Du point de vue hémodynamique, les deux groupes ont des activations semblables, contredisant le phénomène HAROLD. De plus, les participants peu scolarisés tendent à activer de façon plus importante l’hémisphère gauche, peu importe la tâche ou la condition. Par contre, les activations varient selon la tâche et la condition dans le cas du groupe fortement scolarisé. Normal aging is associated with cerebral reorganisation which can be influenced by many factors. For example, the theory cognitive reserve (Stern, 2002) is trying to explain how those factors can have an impact on the reorganization. However, some factors, such as educational level, are known to have an impact on cognitive performance. The aim of this dissertation is to study the effect of educational level in cerebral oxygenation of healthy older adults during both phonologic and semantic verbal fluency tasks. Each task is divided into two criteria: more productive and less productive. Behavioural data showed that less educated elderly generate fewer words than more educated ones for both tasks. Moreover, the differences between the number of words for the more productive criterion and the less productive one are higher for the semantic than for the phonologic task. NIRS data showed that both groups activated prefrontal cortex, without difference between them. In addition, less educated participants tend to have bigger activations in the left hemisphere regardless of the task and the criterion. On the other hand, higher educated participants’ activations vary according to the task and the criterion unlike the HAROLD model’s predictions.