Dementia and risk of visual impairment in Chinese older adults.

We had previously identified visual impairment increasing risk of incident dementia. While a bi-directional vision-cognition association has subsequently been proposed, no study has specifically examined the longitudinal association between dementia and incidence of clinically defined visual impairment. In this territory-wide community cohort study of 10,806 visually unimpaired older adults, we examined their visual acuity annually for 6 years and tested if dementia at baseline was independently associated with higher risk of incident visual impairment (LogMAR ≥ 0.50 in the better eye despite best correction, which is equivalent to moderate visual impairment according to the World Health Organization definition). By the end of Year 6, a total of 3151 (29.2%) participants developed visual impairment. However, we did not find baseline dementia associating with higher risk of incident visual impairment, after controlling for baseline visual acuity, cataract, glaucoma, diabetes, hypertension, hypercholesterolemia, heart diseases, stroke, Parkinson's disease, depression, hearing and physical impairments, physical, intellectual and social activities, diet, smoking, age, sex, educational level, and socioeconomic status. Among different covariables, baseline visual acuity appears to be more important than dementia in contributing to the development of visual impairment. Our present findings highlight the need for re-evaluating whether dementia is indeed a risk factor for visual impairment.

Common mental disorders during the COVID-19 pandemic in Hong Kong: Age-related differences and implications for dementia risk.

Background: The COVID-19 pandemic has imposed a profound negative impact on the mental health and wellbeing of societies and individuals worldwide. Older adults may be more vulnerable to the mental health effects of the pandemic, either directly from the infection itself or indirectly through the preventive measures. However, the existing literature on mental health in the older age groups has not been consistent so far. The aim of this study was therefore to assess the prevalence of common mental disorders (CMD; including depression and anxiety disorders) given their association with dementia risk, and to further examine age-related differences between older (≥60 years old) and younger (18-59 years old) adult's psychological status during the COVID-19 pandemic. Method: This was a secondary analysis of a cross-sectional survey-study conducted during the second wave of COVID-19 pandemic in Hong Kong. The survey was disseminated through different social media platforms to the general population and included sociodemographic questions, self-reported physical health, and previous encounter with SARS or COVID-19. CMD was the primary outcome and was assessed using the 6-item Kessler Scale. A total of 1030 adults fulfilled inclusion criteria. Results: The prevalence of CMD during the pandemic was 16.1%. Compared to younger adults, older adults were significantly less likely to have a CMD (unadjusted OR = 0.07, 95% CI = 0.02-0.30, p < 0.001), with 18.1% of younger adults having CMD compared to 1.6% in the older cohort. Age differences remained significant after controlling for sociodemographic factors, physical health, and previous encounter with SARS or COVID-19 (adjusted OR = 0.12, 95% CI = 0.02-0.57, p = 0.008). Conclusion: Common mental disorders are highly prevalent during the COVID-19 pandemic in Hong Kong, though older adults appeared to be less affected mentally. Present findings highlight the urgent need to implement measures and strategies to mitigate the mental health problems, with particular attention to the younger cohort. Given their association with higher dementia risk, early detection and treatment of depression and anxiety disorders will be of critical importance in providing some relief to the already pressurized dementia burden in the longer term.

Increasing participation in habitual intellectual activities on modulating functional connectivity of default mode network among older adults at risk of dementia: study protocol of a randomized controlled trial.

BACKGROUND: Active participation in intellectual leisure activities such as calligraphy helps prevent cognitive decline and dementia, but the underlying mechanisms are not fully understood. With disrupted functional connectivity (FC) of default mode network (DMN) associated with cognitive decline, we speculate that intellectual activities might optimize cognitive function through modulating FC of DMN. This two-arm single-blind randomized controlled trial aims to identify the effects of increasing practice of calligraphy on cognitive function and FC of DMN in people with subjective cognitive decline (SCD). METHODS: One hundred twelve community-living Chinese aged 55 to 75 years old with SCD but without mild cognitive impairment or dementia and with prior practice of calligraphy as defined by 1 h of calligraphy per week will be recruited through elderly social centres in Hong Kong and randomized into either control or intervention group. The control group will continue with their usual practice of calligraphy, whereas the intervention group will double their practice of calligraphy. Measurement of cognitive outcomes and neuroimaging on resting-state FC will be performed at baseline and in 6 months. Repeated measures analysis of variance will be used to assess cognitive and FC changes, with time being the within-group factor, control/intervention as the between-group measure, and important covariates (age, sex, educational and occupational attainment, health, and other lifestyle factors) controlled for. DISCUSSION: This study will shed light on the underlying neurocognitive mechanisms of how intellectual activities promotes cognitive maintenance. Our anticipated findings will provide evidence that reversing or slowing FC disruption by actively participating in intellectual activities is still possible for the at-risk individuals. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR1900024433 . Registered on 11 July 2019.