17 research outputs found
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.published_or_final_versio
Age, Education, and Cognitive Decline: a prospective study of cognitive function in community-dwelling Chinese older adults in Hong Kong
Conference Theme: Mental Health for AllFree Paper 3.1 – Neuroscience and Mental HealthBackground: This study aimed to investigate the changes in
cognitive profiles and the effect of age and education on such
changes in an older community cohort over a 5-year period.
Methods: A random sample of 787 non-demented Chinese
elders in Hong Kong was assessed with a comprehensive
neuropsychological battery at baseline, in the 2nd and 5th
year.
Results: A total of 454 subjects were assessed at the 5th year.
For subjects with normal cognitive function at baseline, 186
(56.9%) remained cognitively normal, 115 (35.2%) had mild
cognitive impairment (MCI), and 26 (7.9%) became demented.
For subjects with MCI at baseline, 28 (22%) reverted to
normal, 59 (46.5%) remained as MCI, 40 (31.5%) became
demented. The decline in scores of Cantonese Mini-Mental
State Examination was significant over the years, with the
rate of decline being greater after the 2nd year. Using logistic
regression, age and education had significant predictive effects
on the progression to dementia, but the protective effect of
education was lost if the subjects were already suffering from
MCI at the baseline. Age was a significant factor affecting the
cognitive function over time, while the effect of education was
lost in the baseline MCI subjects.
Conclusions: A decline in cognitive profile took place before
the clinical diagnosis of dementia. The protective effect of
education on cognitive function appeared to have lost when
the person started to have MCI
Noninvasive Prenatal Diagnosis of Fetal Trisomy 21 by Allelic Ratio Analysis Using Targeted Massively Parallel Sequencing of Maternal Plasma DNA
BACKGROUND: Plasma DNA obtained from a pregnant woman contains a mixture of maternal and fetal DNA. The fetal DNA proportion in maternal plasma is relatively consistent as determined using polymorphic genetic markers across different chromosomes in euploid pregnancies. For aneuploid pregnancies, the observed fetal DNA proportion measured using polymorphic genetic markers for the aneuploid chromosome would be perturbed. In this study, we investigated the feasibility of analyzing single nucleotide polymorphisms using targeted massively parallel sequencing to detect such perturbations in mothers carrying trisomy 21 fetuses. METHODOLOGY/PRINCIPAL FINDINGS: DNA was extracted from plasma samples collected from fourteen pregnant women carrying singleton fetuses. Hybridization-based targeted sequencing was used to enrich 2 906 single nucleotide polymorphism loci on chr7, chr13, chr18 and chr21. Plasma DNA libraries with and without target enrichment were analyzed by massively parallel sequencing. Genomic DNA samples of both the mother and fetus for each case were genotyped by single nucleotide polymorphism microarray analysis. For the targeted regions, the mean sequencing depth of the enriched samples was 225-fold higher than that of the non-enriched samples. From the targeted sequencing data, the ratio between fetus-specific and shared alleles increased by approximately 2-fold on chr21 in the paternally-derived trisomy 21 case. In comparison, the ratio is decreased by approximately 11% on chr21 in the maternally-derived trisomy 21 cases but with much overlap with the ratio of the euploid cases. Computer simulation revealed the relationship between the fetal DNA proportion, the number of informative alleles and the depth of sequencing. CONCLUSIONS/SIGNIFICANCE: Targeted massively parallel sequencing of single nucleotide polymorphism loci in maternal plasma DNA is a potential approach for trisomy 21 detection. However, the method appears to be less robust than approaches using non-polymorphism-based counting of sequence tags in plasma
The De Jong Gierveld short scales for emotional and social loneliness: tested on data from 7 countries in the UN generations and gender surveys
Loneliness concerns the subjective evaluation of the situation individuals are involved in, characterized either by a number of relationships with friends and colleagues which is smaller than is considered desirable (social loneliness), as well as situations where the intimacy in confidant relationships one wishes for has not been realized (emotional loneliness). To identify people who are lonely direct questions are not sufficient; loneliness scales are preferred. In this article, the quality of the three-item scale for emotional loneliness and the three-item scale for social loneliness has been investigated for use in the following countries participating in the United Nations “Generations and Gender Surveys”: France, Germany, the Netherlands, Russia, Bulgaria, Georgia, and Japan. Sample sizes for the 7 countries varied between 8,158 and 12,828. Translations of the De Jong Gierveld loneliness scale have been tested using reliability and validity tests including a confirmatory factor analysis to test the two-dimensional structure of loneliness. Test outcomes indicated for each of the countries under investigation reliable and valid scales for emotional and social loneliness, respectively
Loneliness of Older Immigrant Groups in Canada: Effects of Ethnic-Cultural Background
This study aimed to explore the loneliness of several groups of older immigrants in Canadacompared to native-born older adults. Data from the Canadian General Social Survey, Cycle 22 (Nolder adults = 3,692) were used. The dependent variable is the 6 item De Jong Gierveld lonelinessscale. Determinants of loneliness included country of birth, ethnic background (cultural context);belongingness (community context) and social networks (social context). Results showed that onlysome immigrant groups are significantly lonelier than older adults born in Canada. Immigrants withsimilar language and culture are not lonelier; while those from countries that differ in nativelanguage/culture are significantly higher on loneliness. Multivariate analyses showed the importanceof cultural background, of composition of the network of relatives and friends, and of localparticipation and feelings of belonging to the Canadian society in explaining loneliness of olderimmigrants
Cognitive Reserve and the Prevention of Dementia: the Role of Physical and Cognitive Activities
Purpose of Review: The article discusses the two most significant modifiable risk factors for dementia, namely, physical inactivity and lack of stimulating cognitive activity, and their effects on developing cognitive reserve. Recent Findings: Both of these leisure-time activities were associated with significant reductions in the risk of dementia in longitudinal studies. In addition, physical activity, particularly aerobic exercise, is associated with less age-related gray and white matter loss and with less neurotoxic factors. On the other hand, cognitive training studies suggest that training for executive functions (e.g., working memory) improves prefrontal network efficiency, which provides support to brain functioning in the face of cognitive decline. Summary: While physical activity preserves neuronal structural integrity and brain volume (hardware), cognitive activity strengthens the functioning and plasticity of neural circuits (software), thus supporting cognitive reserve in different ways. Future research should examine whether lifestyle interventions incorporating these two domains can reduce incident dementia
The effectiveness of functional electrical stimulation (FES) in on-off mode for enhancing the cycling performance of team phoenix at 2016 cybathlon
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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)
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 (χ 2=4.90, P= 0.03). Aberrant motor behaviour was also significantly associated with deterioration in cognition (χ 2= 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. © The Author 2010. Published by Oxford University Press on behalf of the British Geriatrics Society. All rights reserved.link_to_subscribed_fulltex