Factors associated with social participation in Brazilian older adults with Alzheimer's disease: A correlational, cross-sectional study.

The occurrence of Alzheimer's disease (AD) can exert a negative impact in social participation in affected older adults. The purpose of this study was to investigate whether social participation in older adults with AD is associated with disease stage and cognitive function as well as the quality of life and depressive symptoms in their caregivers. A correlational, cross-sectional study was conducted in 40 older adults with AD (28 women and 12 men) and 40 caregivers (30 women and 10 men). Social participation was assessed using the 'social participation' domain of the Activities of Daily Living Questionnaire. Disease stage was determined using the Clinical Dementia Rating scale and cognitive function was assessed using Addenbrooke's Cognitive Examination. Quality of life and depressive symptoms in the caregivers were evaluated using the Quality of Life Assessment Scale on Alzheimer's Disease and Beck Depression Inventory respectively. The older adults with AD had a mean percentage of 59.4% on the social participation domain and a mean score of 49.0 for cognitive function. The caregivers had mean scores of 39.1 for quality of life and 9.9 for depressive symptoms. The stepwise backward multiple linear regression model indicated that the predictors analysed together explained 48% of the variability in social participation among older adults with AD. Therefore, lower social participation among older adults with AD is associated with more advanced stages of the disease and cognitive decline in these individuals as well as a lower perception of quality of life and greater levels of depressive symptoms in their caregivers.

Progression of Gait Changes in Older Adults With Mild Cognitive Impairment: A Systematic Review.

BACKGROUND AND PURPOSE: The identification of altered gait and its progression over time is important to gaining a better understanding of the clinical aspects of mild cognitive impairment (MCI) in older adults. The aim of the present systematic review was to determine changes in gait variables over time among older adults with MCI. METHODS: The PubMed, Web of Science, Scopus, and Science Direct databases were searched for relevant articles using the following keywords and Medical Subject Headings: Aged AND "Mild cognitive impairment" AND (gait OR locomotion). A hand search was also performed of the reference lists of the selected articles in an attempt to find additional records. The following were the inclusion criteria: longitudinal studies and clinical trials involving a control group without intervention; samples of individuals 65 years or older; and characterization of gait using a single or dual task. RESULTS AND DISCUSSION: The initial search led to the retrieval of 6979 studies, 9 of which met the inclusion criteria. The duration of follow-up among the studies ranged from 6 months to 2 years. Most trials investigated gait speed. Other gait variables were step length, time required to walk a given distance, and mean weekly gait speed. Altered gait progressed in older adults with MCI. The main alterations were gait speed and variability in daily number of steps in follow-up periods lasting more than 1 year. No significant changes in gait variables were found in shorter follow-up periods (up to 6 months). CONCLUSIONS: The progression of gait changes in older adults with MCI has been underinvestigated. MCI leads to reduced gait speed in longer follow-up periods. Such information can contribute to the determination of motor interventions for older adults with MCI, especially in the early stages.

Performance of an Adapted Version of the Timed Up-and-Go Test in People with Cognitive Impairments.

In clinical practice, older people with cognitive impairment may have difficulties to understand the instructions of the Timed Up-and-Go (TUGT) test and present a bad performance. The purpose of this study was to identify differences in the TUGT performance, in an adapted version, between older adults with preserved cognition (PC), mild cognitive impairment (MCI) and Alzheimer's disease (AD), and to identify the association between the adapted TUGT performance and cognition among groups. A cross-sectional study was conducted with 118 community-dwelling older adults divided in three groups: PC (n = 40), MCI (n = 40) and AD (n = 38). The evaluation was composed by the adapted TUGT and cognitive assessment (Addenbrooke's Cognitive Examination and Frontal Assessment Battery). Only the cadence of TUGT presented significant difference between groups, specifically between AD versus MCI and PC groups. The main correlations were found between time of TUGT with fluency domain and global cognitive function, especially in the AD Group. The findings contribute to the understanding of how cognition interferes on functional mobility in older people with MCI and AD. The adapted TUGT is easy to perform in clinical practice and can be useful when assessing mobility in people with cognitive impairment.

Dual-Task Performance: Influence of Frailty, Level of Physical Activity, and Cognition.

BACKGROUND AND PURPOSE: Cognition and level of physical activity have been associated with frailty syndrome. The development of tools that assess deficits related to physical and cognitive frailties simultaneously are of common interest. However, little is known about how much these aspects influence the performance of dual-task tests. Our aims were (a) to verify the influence of frailty syndrome and objectively measured physical activity and cognition on the Timed Up and Go (TUG) test and Timed Up and Go associated with dual-task (TUG-DT) performances; and (b) to compare TUG and TUG-DT performances between older adults who develop frailty syndrome. METHODS: Sixty-four community-dwelling older adults were divided into frail, prefrail, and nonfrail groups, according to frailty phenotype. Assessments included anamnesis, screening of frailty syndrome, cognitive assessment (Addenbrooke's Cognitive Examination), placement of a triaxial accelerometer to assess level of physical activity, and TUG and TUG-DT (TUG associated with a motor-cognitive task of calling a phone number) performances. After 7 days, the accelerometer was removed. A multiple linear regression was applied to identify which independent variables could explain performances in the TUG and TUG-DT. Subsequently, the analysis of covariance test, adjusted for age, cognition, and level of physical activity covariates, was used to compare test performances. RESULTS: There were no differences in cognition between groups. Significant differences in the level of physical activity were found in the frail group. Compared with the frail group, the nonfrail group required less time and fewer steps to complete the TUG. Regarding the TUG-DT, cognition and age influenced the time spent and number of steps, respectively; however, no differences were found between groups. CONCLUSIONS: Frail older adults presented worse performance in the TUG when compared with nonfrail older adults. The dual-task test does not differentiate older adults with frailty syndrome, regardless of cognitive performance.

Physical exercise improves peripheral BDNF levels and cognitive functions in mild cognitive impairment elderly with different bdnf Val66Met genotypes.

The benefits of physical exercise on improvements in brain-derived neurotrophic factor (BDNF) levels and cognitive functioning have been reported in the literature. However, the variability of individual responses may be linked to genetic differences. BDNF is considered one of the most plausible factors involved in the cognitive benefits associated with physical activity practice. A single nucleotide polymorphism localized in the gene that codes BDNF results in a missense mutation that promotes an amino acid substitution (Val66Met) in the protein. This process has been associated with decreased levels of BDNF secretion, with corresponding impairments in specific cognitive functions. Therefore, the objective of this study was to analyze the effects of a multimodal physical exercise program on peripheral BDNF levels and cognitive functions in elderly individuals with mild cognitive impairment (MCI). The participants were genotyped for the BDNF Val66Met polymorphism. Cognitive functions were assessed by the Montreal Cognitive Assessment (MoCA) prior to and after the intervention. Forty-five participants were assigned to the control and trained groups. The trained group participated in a multimodal physical training for a 16-week period. The results showed a significant between-subjects interaction (p < 0.05), which indicates the beneficial contribution of training on cognitive functions independent of the BDNF genotype. However, only participants with BDNF-Met genotypes exhibited significant improvements in peripheral BDNF levels. The BDNF genotype appears to modulate the effects of physical exercise on BDNF secretion, but it does not influence cognition. This is the first study that evaluated the influence of a BDNF polymorphism on physical activity and cognition performance in elderly MCI individuals.