Physical activity and cognitive function of community Chinese elderly in Hong Kong (HK) and Guangzhou (GZ).

BACKGROUND: Some studies demonstrated that physical activity may have beneficial effect on cognitive function. The objective of the study was to estimate the association between physical activity and cognitive function in community-dwelling elderly Chinese in Hong Kong (HK) and Guangzhou (GZ). METHODS: In the neighborhood of HK and GZ, a convenience sample of 557 (260 in HK and 297 in GZ) older persons without dementia aged over 60 years (73.4 ± 6.5) was recruited. Physical activity was measured using a checklist. Information on physical activity participation, cognitive function, and other variables were collected. Multivariate linear regression analyses were performed to evaluate the association between physical activity and cognitive function. RESULTS: Total number of physical activities showed significant association with the delayed recall test (p 0.05) CONCLUSION: Physical activity may not be associated with better cognitive function among elderly Chinese independently of other factors.

The utility of a non-verbal prospective memory measure as a sensitive marker for early-stage Alzheimer's disease in Hong Kong.

ABSTRACT Background: With the proportion of older adults in Hong Kong projected to double in size in the next 30 years, it is important to develop measures for detecting individuals in the earliest stage of Alzheimer's disease (AD, 0.5 in Clinical Dementia Rating, CDR). We tested the utility of a non-verbal prospective memory task (PM, ability to remember what one has to do when a specific event occurs in the future) as an early marker for AD in Hong Kong Chinese. Methods: A large community dwelling sample of older adults who are healthy controls (CDR 0, N = 125), in the earliest stage of AD (CDR 0.5, N = 125), or with mild AD (CDR 1, N = 30) participated in this study. Their reaction time/accuracy data were analyzed by mixed-factor analyses of variance to compare the performance of the three CDR groups. Logistic regression analyses were performed to test the discriminative power of these measures for CDR 0 versus 0.5 participants. Results: Prospective memory performance declined as a function of AD severity: CDR 0 > CDR 0.5 > CDR 1, suggesting the effects of early-stage AD and AD progression on PM. After partialling out the variance explained by psychometric measures (e.g., ADAS-Cog), reaction time/accuracy measures that reflected the PM still significantly discriminated between CDR 0 versus 0.5 participants in most of the cases. Conclusion: The effectiveness of PM measures in discriminating individuals in the earliest stage of AD from healthy older adults suggests that these measures should be further developed as tools for early-stage AD discrimination.

Structured assessment of mental capacity to make financial decisions in Chinese older persons with mild cognitive impairment and mild Alzheimer disease.

Previous studies suggested that patients with mild cognitive impairment (MCI) or dementia can have impaired and declining financial skills and abilities. The purpose of this study is to test a clinically applicable method, based on the contemporary legal standard, to examine directly the mental capacity to make financial decisions and its component decision-making abilities among patients with MCI and early dementia. A total of 90 patients with mild Alzheimer disease (AD), 92 participants with MCI, and 93 cognitively normal control participants were recruited for this study. Their mental capacity to make everyday financial decisions was assessed by clinician ratings and the Chinese version of the Assessment of Capacity for Everyday Decision-Making (ACED). Based on the clinician ratings, only 53.5% were found to be mentally competent in the AD group, compared with 94.6% in the MCI group. However, participants with MCI had mild but significant impairment in understanding, appreciating, and reasoning abilities as measured by the ACED. The ACED provided a reliable and clinically applicable structured framework for assessment of mental capacity to make financial decisions.

Cognitive predictors for five-year conversion to dementia in community-dwelling Chinese older adults.

BACKGROUND: This study evaluates which cognitive measure is best for predicting incident dementia in a population-based random sample of Chinese older adults without dementia over a five-year period. METHODS: A total of 787 community-dwelling Chinese older adults without dementia in Hong Kong were assessed at baseline (T0), at two years (T1), and at five years (T2). RESULTS: The annual conversion rate to dementia was 1.6% and 6.3% for baseline normal participants and baseline mild cognitive impairment (MCI) participants, respectively. The Cantonese version of Mini-mental State Examination (CMMSE) scores declined significantly over time. In participants who progressed to dementia, Category Verbal Fluency Test (CVFT) scores dropped significantly from T0 to T1. A 1-SD drop of either CMMSE or CVFT in two years predicted dementia at five years with 91.5% sensitivity and 62.0% specificity. A stable CMMSE and CVFT at two years predicted a 91% chance of not progressing to clinical dementia at five years. CONCLUSION: In this community sample of Chinese older adults, a decline in cognitive screening tests in short term (two years) offered useful information in predicting dementia conversion over a longer period.

Effects of education on very mild dementia among Chinese people in Hong Kong: potential mediators in the Cantonese Mini-Mental State Examination tasks.

BACKGROUND: In Hong Kong, older Chinese adults generally have a low level of education. This study examined the effect of education on very mild Alzheimer's disease (AD), as quantified by Clinical Dementia Rating (CDR) scale (CDR 0.5 versus 0), in a Chinese community. The Cantonese version of the Mini-Mental State Examination (C-MMSE) was used to estimate cognitive abilities that were related to the level of education, and that in turn serve as protective factors for AD. METHODS: A total of 788 community-dwelling older adults (383 CDR 0 and 405 CDR 0.5) were recruited in this cross-sectional study, which was derived from a population-based prevalence project. The participants' number of years of education and C-MMSE scores were used to predict their CDR scores using logistic regression and the mediation effects of C-MMSE scores were analyzed. RESULTS: Consistent with previous studies, the chance of being rated as having very mild AD increased with age, but decreased with years of education, among the older adult community of Hong Kong. The effect of education on very mild dementia was weakened substantially when C-MMSE scores were included as mediating variables. CONCLUSIONS: The findings indicate that the protective effects of education on dementia were mediated by an enhancement of older adults' performance on some C-MMSE items, including attention and orientation to time and place.

Interim follow-up of a randomized controlled trial comparing Chinese style mind body (Tai Chi) and stretching exercises on cognitive function in subjects at risk of progressive cognitive decline.

OBJECTIVES: We reported the interim findings of a randomized controlled trial (RCT) to examine the effects of a mind body physical exercise (Tai Chi) on cognitive function in Chinese subjects at risk of cognitive decline. SUBJECTS: 389 Chinese older persons with either a Clinical Dementia Rating (CDR 0.5) or amnestic-MCI participated in an exercise program. The exercise intervention lasted for 1 year; 171 subjects were trained with 24 forms simplified Tai Chi (Intervention, I) and 218 were trained with stretching and toning exercise (Control, C). The exercise comprised of advised exercise sessions of at least three times per week. RESULTS: At 5th months (2 months after completion of training), both I and C subjects showed an improvement in global cognitive function, delayed recall and subjective cognitive complaints (paired t-tests, p < 0.05). Improvements in visual spans and CDR sum of boxes scores were observed in I group (paired t-tests, p < 0.001). Three (2.2%) and 21(10.8%) subjects from the I and C groups progressed to dementia (Pearson chi square = 8.71, OR = 5.34, 95% CI 1.56-18.29). Logistic regression analysis controlled for baseline group differences in education and cognitive function suggested I group was associated with stable CDR (OR = 0.14, 95%CI = 0.03-0.71, p = 0.02). CONCLUSIONS: Our interim findings showed that Chinese style mind body (Tai Chi) exercise may offer specific benefits to cognition, potential clinical interests should be further explored with longer observation period.

Neuropsychiatric symptoms are associated with increased risks of progression to dementia: a 2-year prospective study of 321 Chinese older persons with mild cognitive impairment.

BACKGROUND: studies have suggested that neuropsychiatric (NP) symptoms influence the development of dementia among older adults. But, the results are inconsistent and there is limited information about NP symptoms in population-based samples. OBJECTIVE: to explore the association between NP symptoms and risk of cognitive decline in Chinese older persons residing in the community. DESIGN: prospective study. SETTING: community sample. SUBJECTS: a total of 321 community-dwelling Chinese older persons aged 60 or over with mild cognitive impairment participated in the study. METHODS: at baseline, each subject was assessed with Clinical Dementia Rating (CDR), Mini-Mental State Examination, list learning and delayed recall, and Category Verbal Fluency Test. Severity of NP symptoms was evaluated with Neuropsychiatric Inventory (NPI). Global cognitive status at the end of 2-year study period was determined by CDR. RESULTS: at baseline, 40.5% of participants exhibited one or more NP symptoms (NPI total score ≥ 1). Night-time behaviours (22.1%), depression (16.8%), apathy (14.0%) and anxiety (12.8%) were the most common NP symptoms. At the end of 2-year follow-up, 27.5% of participants with depression at baseline developed dementia, compared with 14.8% of those without depression (χ² = 4.90, P= 0.03). Aberrant motor behaviour was also significantly associated with deterioration in cognition (χ² = 5.84, P= 0.02), although it was an infrequent occurrence. On logistic regression analysis, only depression at baseline was shown to be a risk factor for progression to dementia (OR= 2.40, 95% CI 1.05-5.46, P= 0.04). CONCLUSION: depression in non-demented older persons may represent an independent dimension reflecting early neuronal degeneration. Further studies should be conducted to assess whether effective management of NP symptoms exerts beneficial effects on cognitive function.

Combined clinical and cognitive criteria to identify mild cognitive impairment in a southern Chinese community.

Mild Cognitive Impairment (MCI) is a recognized risk condition for clinical dementia. This paper attempted to explore the applicability of a combined cognitive and clinical approach to identify older Chinese adults at-risk of cognitive decline. Seven hundred forty randomly recruited community dwelling participants (aged 60 or over) were assessed at baseline and 2 years with Clinical Dementia Rating (CDR) and a cognitive battery. Baseline MCI groups were categorized by CDR-MCI, cognitive function (Cog-MCI), and a combined CDR-Cog approach. The cognitive approach adopted the Mayo clinic criteria. For the combined approach, nonamnestic MCI combined CDR 0.5 plus nonmemory cognitive deficits. The overall concordance between CDR and Cognitive test ratings were 65.3% (χ2 = 256.4, P<0.001, κ=0.44). With a combined approach, 424 (57%) participants were classified as normal. CDR-MCI group had higher cognitive scores compared with MCI groups by other criteria (1 way analysis of variance or ANOVA). At 2 years, the combined CDR-Cog MCI group identified all dementia (N=24) converters although group differences were not significant. Cognitive function and CDR identified participants potentially at-risk for furthermore decline, but exhibited some differences in detection profiles. A combined approach may be more practical in screening for MCI participants with diverse educational and cultural background.

Examining the association between participation in late-life leisure activities and cognitive function in community-dwelling elderly Chinese in Hong Kong.

BACKGROUND: Growing evidence suggests that participation in late-life leisure activity may have beneficial effects on cognitive function. The objective of the study was to evaluate the association between leisure activity participation and cognitive function in an elderly population of community-dwelling Hong Kong Chinese. METHODS: 512 participants were assessed in the follow-up study of a population-based community survey of the prevalence of cognitive impairment among Hong Kong Chinese aged 60 years and over. Leisure activities were classified into four categories (physical, intellectual, social and recreational). Information regarding leisure activity participation, cognitive function and other variables was collected. Multivariate linear regression analyses were performed to examine the association between leisure activity participation and cognitive function. RESULTS: A higher level of late-life leisure activity participation, particularly in intellectual activities, was significantly associated with better cognitive function in the elderly, as reflected by the results of the Cantonese Mini-mental State Examination (p = 0.007, 0.029 and 0.005), the Category Verbal Fluency Test (p = 0.027, 0.003 and 0.005) and digit backward span (p = 0.031, 0.002 and 0.009), as measured by the total frequency, total hours per week and total number of subtypes, respectively; the Chinese Alzheimer's Disease Assessment Scale-Cognitive Subscale (p = 0.045) and word list learning (p = 0.003), as measured by the total number of subtypes; and digit forward span (p = 0.007 and 0.015), as measured by the total hours per week and total number of subtypes, respectively. CONCLUSION: Late-life intellectual activity participation was associated with better cognitive function among community-dwelling Hong Kong elderly Chinese.

Physical Exercise Helped to Maintain and Restore Functioning in Chinese Older Adults With Mild Cognitive Impairment: A 5-Year Prospective Study of the Hong Kong Memory and Ageing Prospective Study (HK-MAPS).

OBJECTIVE: This study investigated the potential of physical exercise habit as a lifestyle modification against cognitive and functional decline at the community level. METHODS: A total of 454 community-dwelling Chinese older adults without dementia participated in the Hong Kong Memory and Ageing Prospective Study at baseline and follow-up at 5 years. Their cognitive and functional performances were assessed by the Cantonese version of the Mini-Mental State Examination (CMMSE) and the Chinese version of Disability Assessment in Dementia (DAD). Hierarchical multiple regression analyses were performed to examine whether physical exercise was a significant predictor of the follow-up CMMSE and DAD scores after controlling for the covariates. Subgroup analyses were performed with a group of 127 participants with mild cognitive impairment at baseline. RESULTS: Physical exercise habit was a significant predictor for both the follow-up CMMSE scores and DAD scores. Participants with exercise habits of 5 years or more showed better cognitive and functional performances at follow-up. Participants who picked up exercise habits only after the baseline assessment also demonstrated better functioning at follow-up. The same patterns were observed in the subgroup analyses with the mild cognitive impairment group. CONCLUSION: Results suggested that prolonged exercise habit is required for positive effects on cognition to emerge, but benefits on functioning can be observed when individuals take up an exercise habit later in life or even after the beginning of cognitive decline. These findings are encouraging in promoting an exercise habit among older adults living in the community.

A 1-year randomized controlled trial comparing mind body exercise (Tai Chi) with stretching and toning exercise on cognitive function in older Chinese adults at risk of cognitive decline.

OBJECTIVES: To compare the effectiveness of Chinese-style mind-body exercise (24 forms simplified Tai Chi) versus stretching and toning exercise in the maintenance of cognitive abilities in Chinese elders at risk of cognitive decline. DESIGN: A 1-year single-blind cluster randomized controlled trial. SETTINGS: Community centers and residential homes for elders in Hong Kong. PARTICIPANTS: A total of 389 subjects at risk of cognitive decline (Clinical Dementia Rating, CDR 0.5 or amnestic-MCI) participated in an exercise intervention program. INTERVENTION: A total of 171 subjects were trained with Tai Chi (Intervention [I]) and 218 were trained with stretching and toning exercise (Control [C]). METHODS: Cognitive and functional performance were assessed at the baseline, and at 5, 9, and 12 months. Data were analyzed using multilevel mixed models. Primary outcomes included progression to clinical dementia as diagnosed by DSM-IV criteria, and change of cognitive and functional scores. Secondary outcomes included postural balance measured by the Berg Balance Scale neuropsychiatric and mood symptoms measured by the Neuropsychiatric Inventory, and Cornell Scale for Depression in Dementia. RESULTS: At 1 year, 92 (54%) and 169 (78%) participants of the I and C groups completed the intervention. Multilevel logistic regression with completers-only analyses controlled for baseline differences in education revealed that the I group had a trend for lower risk of developing dementia at 1 year (odds ratio 0.21, 95% CI 0.05-0.92, P = .04). The I group had better preservation of CDR sum of boxes scores than the C group in both intention-to-treat (P = .04) and completers-only analyses (P = .004). In completers-only analyses, the I group had greater improvement in delay recall (P = .05) and Cornell Scale for Depression in Dementia scores (P = .02). CONCLUSION: Regular exercise, especially mind-body exercise with integrated cognitive and motor coordination, may help with preservation of global ability in elders at risk of cognitive decline; however, logistics to promote long-term practice and optimize adherence needs to be revisited.