Linda C. W. Lam

Prevalence of very mild and mild dementia in community-dwelling older Chinese people in Hong Kong

INTRODUCTION In this report, the results of a household survey were used to examine the prevalence of very mild and mild dementia in Chinese older persons in Hong Kong. METHODS The study adopted a two-phase design. At Phase 1, 6100 subjects were screened using the Cantonese version of the Mini-mental State Examination (MMSE) and a short memory inventory. At Phase 2, 2073 subjects were screened positive and 737 were evaluated by psychiatrists. Clinical Dementia Rating (CDR) and cognitive assessment were used for diagnosis of dementia. Very mild dementia (VMD) was defined as a global CDR of 0.5, with memory and non-memory subscale scores of 0.5 or more. Mild dementia was classified for subjects with a CDR of 1. RESULTS The overall prevalence of VMD and mild dementia for persons aged 70 years or above was 8.5% (95%CI: 7.4-9.6) and 8.9% (95%CI: 7.8-10.0) respectively. Among subjects with clinical dementia, 84.6% had mild (CDR1) dementia. Logistic regression analyses revealed that older age, lower educational level and significant cerebrovascular risk factors were risk factors for dementia, while regular physical exercise was a protective factor for dementia. CONCLUSIONS A sizable proportion of community-living subjects suffered from milder forms of dementia. They represent a high risk for early intervention to reduce potential physical and psychiatric morbidity.

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.

The association between promoter polymorphism of the interleukin-10 gene and Alzheimer's disease

The importance of the role of inflammation has been suggested in the pathogenesis of Alzheimers disease (AD). Interleukin-10 (IL-10) is an anti-inflammatory cytokine that may modulate the progression of the disease through the inhibition of the action of pro-inflammatory cytokines. In this study, three polymorphisms in the regulatory region of the IL-10 gene (-1082, -819 and -592) in 95 Chinese AD patients and 117 age-matched healthy Chinese subjects were investigated. We found that among the Chinese population, the A and C alleles at the -592 position are strongly linked to the T and C alleles at the -819 position, respectively. A strong association with AD was found for these two IL-10 polymorphisms, which are in complete linkage disequilibrium (-592C and -819C), and the odds ratio of AD is 4.03 (95% CI 1.23-13.23; p = 0.011). The functional significance of the IL-10 genotype was further supported by the significant association between plasma IL-10 concentrations and genotypes that were found in an independent sample of 160 healthy male volunteers. No interaction effect between the ApoE and IL-10 genotypes is found. Therefore, we concluded that the functional polymorphisms of the IL-10 gene act as a risk factor for AD.

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

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.

Apolipoprotein E ε4 Allele Is Associated with Vascular Dementia

Background/Aims: The apolipoprotein E (ApoE) exon 4 polymorphism has been associated with vascular dementia (VaD) risk. Since not all studies confirm this finding, we explored this association in a case-control study. Methods: We genotyped ApoE in 144 VaD patients and 251 controls. Results: VaD patients were more likely than controls to have ApoE Ε3/Ε4 or Ε4/Ε4 genotypes: 23.6% versus 15.1%, odds ratio (OR) = 1.7, p = 0.036. This association remained significant after adjustment for age, sex, hypertension and diabetes by multiple logistic regression: OR = 1.9, p = 0.030. The association of Ε3/Ε4 or Ε4/Ε4 genotypes with VaD was strong among people with hypertension (OR = 2.9, p = 0.007) or diabetes (OR = 6.5, p = 0.011). The association was absent among people without hypertension (OR = 1.1, p = 0.79) or diabetes (OR = 1.3, p = 0.43). Conclusion: This interaction with hypertension and diabetes should be examined in other studies to confirm or refute this observation.

Association between mind-body and cardiovascular exercises and memory in older adults

Objectives: To compare the memory function of older adults who regularly practiced mind‐body (MB) or cardiovascular (CV) exercises with that of those who did not engage in regular exercise. Older adults who engaged in both types of exercise were also included to examine the combined effects.

Self-efficacy Is Associated With Less Burden and More Gains From Behavioral Problems of Alzheimer’s Disease in Hong Kong Chinese Caregivers

PURPOSE To test the effects of different self-efficacy beliefs on caregiver appraisals and depressive symptoms. We hypothesized that self-efficacy has a direct effect on depression while moderating the effects of behavioral problems on both negative (i.e., burden) and positive (i.e., uplifting) appraisals. DESIGN AND METHODS Ninety-nine Chinese caregivers of relatives with Alzheimers disease responded to measures of self-efficacy, positive gains, burden, depression, and care recipient behavioral problems. Data were analyzed using confirmatory factor analysis and multiple regression. RESULTS Confirmatory factor analysis supported a 3-factor structure for the Revised Scale for Caregiving Self-Efficacy (obtaining respite, responding to disruptive behaviors, and controlling upsetting thoughts). Interaction effects in regression showed that caregivers with higher self-efficacy in controlling upsetting thoughts had more positive gains and less burden when confronted with more behavioral problems. Self-efficacy in obtaining respite had direct effects on burden and depression, and self-efficacy in responding to disruptive behaviors had a direct effect on positive gains, but not moderating effects. IMPLICATIONS The results supported the multidimensional structure of caregiver self-efficacy and showed that efficacy in controlling upsetting thoughts was most important in buffering the effects of behavioral problems on burden and positive gains among Chinese caregivers. Interventions for dementia caregivers may be more effective if more emphasis is given on changing negative thoughts.

Verbal fluency in schizophrenia: reduction in semantic store

Objective: This is a study of the word production of patients with schizophrenia using a semantic verbal fluency task to address the unresolved issue of retrieval or storage impairment. Method: Twenty-one patients with schizophrenia and 11 matched healthy subjects performed a semantic verbal fluency task on ‘food’, ‘animal’ and ‘transport’ categories in Cantonese for 3 minutes each on five separate trials. Results: Patients generated significantly fewer numbers of words compared with control on each trial. The estimated lexicon size of the patients was significantly smaller than that of the equivalent group. The amount of shared words and variable words generated in all five trials were reduced in the patient group. Conclusions: Our results suggest that poor verbal fluency in patients with schizophrenia may partly be attributable to reduction in semantic store. The importance of temporal lobe involvement on verbal fluency deficits needs to be emphasised as an integral part of the neurobiological basis of schizophrenia research.

Dopamine D3 receptor gene and tardive dyskinesia in Chinese schizophrenic patients

Summary. Epidemiological studies have shown a lower prevalence of tardive dyskinesia (TD) among Chinese psychiatric patients compared to Caucasian and Black patient populations. It has been hypothesized that pharmacogenetic factors may underlie this cross-cultural difference. Due to the important implications of the dopamine D3 receptor gene (DRD3) in motor control, we investigated the frequency of polymorphic serine (ser) to glycine (gly) substitution of the gene DRD3 in Chinese schizophrenic patients. The sample size consisted of 65 patients with TD and 66 without TD. Patients were assessed for the severity of TD, the presence of akathisia and parkinsonian symptoms and were subsequently genotyped. We found no evidence that the dopamine D3 receptor gene is likely to confer susceptibility to the development of tardive dyskinesia in Chinese patients with schizophrenia.

A randomized controlled trial to examine the effectiveness of case management model for community dwelling older persons with mild dementia in Hong Kong

To evaluate a case management (CM) model for people with mild dementia, whereby resources within the family and in the community were mobilized and optimally used.