Prevalence, Risk Factors, and Complaints Screening Tool Exploration of Subjective Cognitive Decline in a Large Cohort of the Chinese Population

Independent and combined associations of handgrip strength and walking speed with cognitive function in older adults: evidence from a national cross-sectional study

OBJECTIVES

Although there have been studies on the association of handgrip strength or walking speed alone with cognitive abilities, few studies have determined the combined associations of handgrip strength and walking speed with cognitive function. Therefore we aimed to explore the independent and combined associations of handgrip strength and walking speed with cognitive function in Chinese older adults using a nationally representative sample.

METHOD

This cross-sectional study included 4,577 adults aged 60 and older. Handgrip strength was measured using a dynamometer and walking speed was assessed using a 2.5-meter walking test. Both handgrip strength and walking speed were organized into low, normal, and high tertiles according to the sample distribution. Cognitive function was measured using the Telephone Interview for Cognitive Status.

RESULTS

Handgrip strength and walking speed were significantly associated with cognitive function. Participants with low handgrip strength or low walking speed separately had a higher rate of lower cognitive function (adjusted odds ratio (OR): 1.22 (95% CI: 1.04 - 1.44) for low handgrip strength; 1.54 (95% CI: 1.31 - 1.81) for low walking speed). Those with both low handgrip strength and low walking speed had an additively higher rate of lower cognitive function (adjusted OR: 1.72 (95% CI: 1.32 - 2.24)).

CONCLUSION

Having low handgrip strength or low walking speed is associated with a greater likelihood of lower cognitive function and vice versa. The concurrence of having low handgrip strength and low walking speed has an additive effect on cognitive function in older adults.

Accelerated long-term forgetting: from subjective memory decline to a defined clinical entity

Subjective memory decline (SMD) might represent the preclinical phase of Alzheimer's disease (AD), and has been reported in epileptic amnesia associated with accelerated long-term forgetting (ALF). We investigated ALF in SMD subjects by means of RAVLT recall and recognition and ROCF recall after 1-week retention and compared with a control group. Two-way ANOVAs for RAVLT and ROCF were conducted, and stepwise regression analysis was administered considering EMQ and DASS-21 as factors. SMD subjects performed significantly worse than controls at 1-week delay on RAVLT recall and recognition, but not on ROCF, and not associated with depression or memory complaints. SMD patients showed ALF, which is usually associated with temporomesial dysfunctions, representing a cognitive marker to assess objectively memory problems in SMD, and to undisclose initial neurodegenerative disease involving temporal structures usually compromised in AD. Therefore, SMD might no longer be "subjective," but rather a specific and defined clinical entity.

Everyday functioning among older adults with subjective cognitive decline: a scoping review

PURPOSE

Older adults with subjective cognitive decline (SCD) experience cognitive difficulties without objectively measurable cognitive impairments but which may affect their everyday functioning. However, everyday functioning in this population has not yet been characterized. We sought to describe the empirical literature on the everyday functioning of community-dwelling older adults with SCD, their recruitment methods, and the measurements used.

METHODS

A scoping review was conducted for primary research articles including at least one measure of everyday functioning. Retrieved records were independently screened. Data were extracted then analyzed using descriptive statistics and summative content analysis.

RESULTS

6544 studies were screened; 21 studies were included. All were observational analytic studies. Most compared an SCD group with a group of healthy control (47.6%), mild cognitive impairment (71.5%), and/or dementia (33.3%). Subjective cognition was measured via interview (28.6%) or clinical question(s) (14.3%). Normal cognition was determined by a wide variety of cognitive tests. The most studied everyday functioning domain was instrumental activities of daily living (90.5%). Most studies used questionnaires (81.0%), and measured ability to do an everyday life task (76.2%).

CONCLUSIONS

More research is needed on everyday functioning other than IADL, with greater focus on measures that consider an individual's real-life participation.

Association between social capital and quality of life in older adults with subjective cognitive decline: A cross-sectional study

BACKGROUND

Subjective cognitive decline (SCD) is increasingly recognized as a clinical and medical risk factor for mild cognitive impairment (MCI) and dementia. Currently, there is little evidence regarding the quality of life (QoL) in older adults with SCD and the impact of social capital on their QoL.

AIMS

To examine the perceptions of social capital and QoL among older adults with SCD.

METHODS

A total of 325 participants (92.9 % response rate) with a self-reported diagnosis of SCD completed the Chinese version of the 36-item Short-Form Health Survey, the Chinese Shortened Social Capital Scale and the Generalized Anxiety Disorder Scale. A t-test was used to compare the QoL score of our sample with the Chinese norm. Pearson correlation analysis and multivariate linear regression analysis were used to assess the association of social capital with QoL.

RESULTS

Social capital were strongly correlated with the total QoL, as well as its physical component summary and mental component summary. The QoL score of older adults with SCD was significantly lower than the Chinese norm (P < 0.001). Multivariate analysis showed that social capital, physical activity, nutrition and anxiety symptoms were factors associated with QoL among older SCD population (P < 0.05).

CONCLUSION

The findings of the current study suggest that older adults with SCD may experience lower QoL. Social capital is associated with the QoL in older adults with SCD. These findings have implications for clinicians who work with older adults with SCD.

Separate and combined associations of obesity and handgrip strength with cognitive function in older adults: A national cross-sectional study in China

This study examined the separate and combined associations of obesity and handgrip strength with cognitive function in older adults. In total 4,839 older adults were included in this cross-sectional study, and their body mass index (BMI) and handgrip strength were measured. Cognitive function was evaluated using the Telephone Interview for Cognitive Status. Three individual categories were created for BMI (normal weight: 18.5≤ BMI < 24.0 kg/m2 overweight: 24.0≤ BMI < 28.0 kg/m2 and obesity: BMI ≥ 28.0 kg/m2 and handgrip strength (low, normal, and high tertiles), and then these categories were pooled together. Logistic regression analyses were used to examine the individual and combined associations of obesity and handgrip strength with cognitive function. Results indicated that overweight adults had a lower rate of lower cognitive function than normal weight adults. There was an inverse association between handgrip strength and cognitive function. Participants with overweight and high handgrip strength had a lower likelihood of lower cognitive function compared to those with normal weight and normal handgrip strength. The findings suggested that overweight or high handgrip strength was associated with lower odds of cognitive decline. Moreover, the concurrence of overweight and high handgrip strength had an additive effect on cognitive function in older adults.

High prevalence of subjective cognitive decline in older Chinese adults: a systematic review and meta-analysis

Background

Subjective cognitive decline (SCD) is considered a preclinical stage of Alzheimer's disease. However, reliable prevalence estimates of SCD in the Chinese population are lacking, underscoring the importance of such metrics for policymakers to formulate appropriate healthcare strategies.

Objective

To systematically evaluate SCD prevalence among older Chinese adults.

Methods

PubMed, Web of Science, The Cochrane Library, Embase, CNKI, Wanfang, VIP, CBM, and Airiti Library databases were searched for studies on SCD in older Chinese individuals published before May 2023. Two investigators independently screened the literature, extracted the information, and assessed the bias risk of the included studies. A meta-analysis was then conducted using Stata 16.0 software via a random-effects model to analyze SCD prevalence in older Chinese adults.

Results

A total of 17 studies were included (n = 31,782). The SCD prevalence in older Chinese adults was 46.4% (95% CI, 40.6-52.2%). Further, subgroup analyzes indicated that SCD prevalence was 50.8% in men and 58.9% among women. Additionally, SCD prevalence in individuals aged 60-69, 70-79, and ≥ 80 years was 38.0, 45.2, and 60.3%, respectively. Furthermore, SCD prevalence in older adults with BMI <18.5, 18.5-24.0, and > 24.0 was 59.3, 54.0, and 52.9%, respectively. Geographically, SCD prevalence among older Chinese individuals was 41.3% in North China and 50.0% in South China. In terms of residence, SCD prevalence was 47.1% in urban residents and 50.0% among rural residents. As for retired individuals, SCD prevalence was 44.2% in non-manual workers and 49.2% among manual workers. In the case of education, individuals with an education level of "elementary school and below" had an SCD prevalence rate of 62.8%; "middle school, "52.4%; "high school, "55.0%; and "college and above, "51.3%. Finally, SCD prevalence was lower among married individuals with surviving spouses than in single adults who were divorced, widowed, or unmarried.

Conclusion

Our systematic review and meta-analysis identified significant and widespread SCD prevalence in the older population in China. Therefore, our review findings highlight the urgent requirement for medical institutions and policymakers across all levels to prioritize and rapidly develop and implement comprehensive preventive and therapeutic strategies for SCD.Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023406950, identifier: CRD42023406950.

Prevalence and risk factors for subjective cognitive decline and the correlation with objective cognition among community-dwelling older adults in China: Results from the Hubei memory and aging cohort study

INTRODUCTION

The prevalence and risk factors for subjective cognitive decline (SCD) and its correlation with objective cognition decline (OCD) among community-dwelling older adults is inconsistent.

METHODS

Older adults underwent neuropsychological and clinical evaluations to reach a consensus on diagnoses.

RESULTS

This study included 7486 adults without mild cognitive impairment and dementia (mean age: 71.35 years [standard deviation = 5.40]). The sex-, age-, and residence-adjusted SCD prevalence was 58.33% overall (95% confidence interval: 58.29% to 58.37%), with higher rates of 61.25% and 59.87% in rural and female subgroups, respectively. SCD global and OCD language, SCD memory and OCD global, SCD and OCD memory, and SCD and OCD language were negatively correlated in fully adjusted models. Seven health and lifestyle factors were associated with an increased risk for SCD.

DISCUSSION

SCD affected 58.33% of older adults and may indicate concurrent OCD, which should prompt the initiation of preventative intervention for dementia.

HIGHLIGHTS

SCD affects 58.33% of older adults in China. SCD may indicate concurrent objective cognitive decline. Difficulty finding words and memory impairments may indicate a risk for AD. The presence of SCD may prompt preventative treatment initiation of MCI or dementia. Social network factors may be initial targets for the early prevention of SCD.

AMES: An Automated Self-Administered Scale to Detect Incipient Cognitive Decline in Primary Care Settings

Early identification and intervention of cognitive decline could be effective to prevent progression to dementia. We developed a self-delivered cognitive screening tool, Automated Memory and Executive Screening (AMES), to assess cognitive domains including memory, language, and executive function. 189 participants with diagnoses of mild cognitive impairment (MCI, n = 43), subjective cognitive decline (SCD, n = 29), objectively-defined subtle cognitive decline (obj-SCD, n = 18), and normal controls (NC, n = 99) completed the study. AMES had good convergent validity with conventional scales, and was good to discriminate patients with MCI (area under the curve [AUC] = 0.88; sensitivity = 86%; specificity = 80%) and obj-SCD (AUC = 0.78; sensitivity = 89%; specificity = 63%) from NC. These findings support that AMES is an easy to administer and effective instrument to screen for early cognitive impairment in community-based settings.

Improved Mood Boosts Memory Training Gains in Older Adults With Subjective Memory Complaints via Enhanced Amygdala-hippocampal Connectivity

OBJECTIVE

Older adults with subjective memory complaints (SMC) have a higher risk of dementia and commonly demonstrate symptoms of anxiety. This study examined the neural correlates of group counseling (GC)-boosted memory training (MT) gains.

DESIGN

This study was an active, controlled, randomized trial.

SETTING

Neighborhoods near the Institute of Psychology of the Chinese Academy of Sciences (CAS).

PARTICIPANTS

Community-dwelling older adults, aged 60 or above with a minimum of 6 years of education, were recruited through advertisements and flyers posted at community service stations.

MEASUREMENTS

The amplitude of low-frequency fluctuations and resting-state functional connectivity (rs-FC) analyses were used to examine the neural correlates associated with MT gains enhanced by improved mood in older adults with SMC. Participants were randomly assigned to the combined intervention (CI) or GC group. The CI group received 3 weeks of GC followed by 4 weeks of MT, and the GC group received GC and health lectures. Cognitive function and emotions were assessed before GC (T1), after GC (T2), and after MT (T3). Both groups underwent resting-state functional magnetic resonance imaging scanning at T2 and T3.

RESULTS

Alleviated anxiety was positively correlated with rs-FC between the amygdala and left hippocampus and negatively correlated with rs-FC between the amygdala and right hippocampus. MT improvement was negatively correlated with rs-FC between the amygdala and right hippocampus in the CI group; the correlation was not significant after controlling for emotional changes.

CONCLUSIONS

Amygdala-hippocampal connectivity may be associated with improved mood-enhanced MT gains in individuals with SMC.

Multidomain interventions for non-pharmacological enhancement (MINE) program in Chinese older adults with mild cognitive impairment: a multicenter randomized controlled trial protocol

BACKGROUND

Dementia is characterized by progressive neurodegeneration and therefore early intervention could have the best chance of preserving brain health. There are significant differences in health awareness, living customs, and daily behaviors among Chinese older adults compared to Europeans and Americans. Because the synergistic benefits of multidomain non-pharmacological interventions are consistent with the multifactorial pathogenicity of MCI, such interventions are more appealing, easier to adhere to, and more relevant to daily life than single-mode interventions. One of the aims of this study is to verify the effect of multidomain intervention strategies for MCI patients based on Chinese population characteristics, and the other is to establish a biobank and image database to investigate the pathogenesis and pathways of cognitive impairment.

METHODS

Our study was designed as a national multicenter, community-based randomized controlled trial (RCT). Twelve medical institutions in ten Chinese cities will participate in our study from 2020 to 2024, and 1080 community residents aged 50 and above will be enrolled as participants. Each sub-center will be responsible for 90 participants (30 people per community) across three communities (non-contact control group, health education group, and multidomain intervention group). The community will be the basic unit of the present study, and all participants in each community will receive the same intervention/control measure. Three working groups are set up in each sub-center to manage the three communities independently to minimize interference at the implementation level between the groups. The multidomain intervention group will receive integrated interventions including exercise, nutrition, sleep, health education and mindfulness meditation. All data generated by the research will be analyzed and processed by statistical software (such as SPSS 21.0, Python 3.0, etc.), and part of the research data will be displayed in the form of graphs and tables.

DISCUSSION

In order to achieve a high-quality community intervention study, it is crucial to have a well-designed experimental protocol that follows rigorous scientific methodology. In addition, effective management of quality control measures and monitoring compliance throughout the study process are essential components. This study provides a detailed discussion of stakeholder compliance, research quality control, potential harm and mitigation, auditing, and future plans in order to better address research issues.

TRIAL REGISTRATION

ChiCTR2000035012 (July 27, 2020).

Age-related decreases in global metacognition are independent of local metacognition and task performance

Metacognition refers to a capacity to reflect on and control other cognitive processes, commonly quantified as the extent to which confidence tracks objective performance. There is conflicting evidence about how "local" metacognition (monitoring of individual judgments) and "global" metacognition (estimates of self-performance) change across the lifespan. Additionally, the degree to which metacognition generalises across cognitive domains may itself change with age due to increased experience with one's own abilities. Using a gamified suite of performance-controlled memory and visual perception tasks, we measured local and global metacognition in an age-stratified sample of 304 healthy volunteers (18-83 years; N = 50 in each of 6 age groups). We calculated both local and global metrics of metacognition and quantified how and whether domain-generality changes with age. First-order task performance was stable across the age range. People's global self-performance estimates and local metacognitive bias decreased with age, indicating overall lower confidence in performance. In contrast, local metacognitive efficiency was spared in older age and remained correlated across the two cognitive domains. A stability of local metacognition indicates distinct mechanisms contributing to local and global metacognition. Our study reveals how local and global metacognition change across the lifespan and provide a benchmark against which disease-related changes in metacognition can be compared.

Prevalence and Progression of Subjective Cognitive Decline Among Rural Chinese Older Adults: A Population-Based Study

BACKGROUND

Few community-based studies have examined occurrence and progression of subjective cognitive decline (SCD).

OBJECTIVE

To investigate prevalence and progression of SCD among rural-dwelling Chinese elderly people.

METHODS

This cohort study included 2,488 cognitively unimpaired adults (age≥65 years) who were examined at baseline (2014-2015) and followed in 2018. Demographic, epidemiological, clinical, and neuropsychological data were collected via in-person interviews and clinical examinations following a structured questionnaire. At baseline, SCD was assessed using the self-rated Ascertain Dementia 8-item Questionnaire. At follow-up, Alzheimer's disease (AD) and vascular dementia (VaD) were clinically diagnosed following the international criteria. Data were analyzed using logistic regression models.

RESULTS

The prevalence of SCD was 40.07%. SCD at baseline was associated with the multivariable-adjusted odds ratio (OR) of 1.51 (95% confidence interval 1.10-2.07) for incident cognitive impairment, no dementia (CIND) and 3.11 (1.64-5.93) for incident AD. Among people with SCD at baseline, the multivariable-adjusted OR of incident CIND was 0.55(0.32-0.96) for hyperlipidemia; the multivariable-adjusted OR of incident AD was 1.21 (1.14-1.30) for older age, 0.32 (0.12-0.88) for high education, 2.60 (1.11-6.08) for carrying APOEɛ4 allele, and 0.34 (0.13-0.86) for high social support, whereas the multivariable-adjusted OR of incident VaD was 6.30 (1.71-23.18) for obesity.

CONCLUSION

SCD affects over 40% of rural-dwelling cognitively unimpaired older adults in China. SCD is associated with accelerated progression to CIND and AD. Older age, lack of school education, APOEɛ4 allele, and low social support are associated with an increased risk of progression from SCD to AD, whereas obesity is related to accelerated progression to VaD.

18F-AV45 PET and MRI Reveal the Influencing Factors of Alzheimer's Disease Biomarkers in Subjective Cognitive Decline Population

BACKGROUND

Subjective cognitive decline (SCD) is a self-perceived decline in cognitive ability, which exhibits no objective impairment but increased risk of conversion to mild cognitive impairment and Alzheimer's disease (AD).

OBJECTIVE

To investigate how influencing factors (risk gene, age, sex, and education) affect amyloid-β (Aβ) deposition and gray matter (GM) atrophy in SCD population.

METHODS

281 SCD subjects were included in this study, who underwent clinical evaluation, cognitive ability assessment, apolipoprotein E (APOE) genotyping, 18F-Florbetapir positron emission computed tomography, and magnetic resonance imaging screening. Two-sample t tests and analysis of variance were performed based on voxel-wise outcome.

RESULTS

In 281 SCD subjects with an average age of 63.86, 194 subjects (69.04%) were female, and 56 subjects carried APOE ɛ4 genes. Statistical results revealed APOE ɛ4 gene, age, and sex influenced Aβ deposition in different brain regions; moreover, only the interaction exhibited between age and APOE ɛ4 genes. The GM atrophy of hippocampal, amygdala, precentral, and occipital lobes occurred in the group age over 60. The GM volume of the hippocampal, frontal, and occipital lobe in females was less than males. Education has an effect only on cognitive function.

CONCLUSION

In SCD, APOE ɛ4 gene, age, and sex significantly influenced Aβ deposition and APOE ɛ4 gene can interact with age in impacting Aβ deposition. Both age and sex can affect GM atrophy. The results suggested that female SCD with APOE ɛ4 genes and aged more than 60 years old might exhibit advanced AD biomarkers.

The relationship between depression and subjective cognitive decline in older adults of China: the mediating role of general self-efficacy

Subjective cognitive decline (SCD) is common in older adults and may also be an early marker for future cognitive impairment. Depression is an important influencing factor for subjective cognitive decline in old age. However, the mediating effects of general self-efficacy in depression and subjective cognition are yet to be explored. This study included 308 participants who were ≥60 years. Participants were asked to complete the self-report measures of the Geriatric Depression Scale-15 (GDS-15), Subjective Cognitive Decline-Questionnaire (SCD-Q), and General Self-Efficacy Scale (GSES). We used correlations, regressions, and structural equation models for the analyses. The bootstrapping method was performed to confirm the mediation effect. The subjective cognitive decline was found to be significantly and positively correlated to depression. Bootstrapping mediation analyses indicated that depression could affect SCD not only directly but also indirectly through general self-efficacy. General self-efficacy partly played a mediating role between depression and SCD. Hence, community workers and clinicians should actively help the elderly experiencing low levels of general self-efficacy to reduce their SCD.

Functional and structural alterations of dorsal attention network in preclinical and early-stage Alzheimer's disease

OBJECTIVES

Subjective cognitive decline (SCD) and amnestic mild cognitive impairment (aMCI) are known as the preclinical and early stage of Alzheimer's disease (AD). The dorsal attention network (DAN) is mainly responsible for the "top-down" attention process. However, previous studies mainly focused on single functional modality and limited structure. This study aimed to investigate the multimodal alterations of DAN in SCD and aMCI to assess their diagnostic value in preclinical and early-stage AD.

METHODS

Resting-state functional magnetic resonance imaging (MRI) was carried out to measure the fractional amplitude of low-frequency fluctuation (fALFF), regional homogeneity (ReHo), and functional connectivity (FC). Structural MRI was used to calculate the gray matter volume (GMV) and cortical thickness. Moreover, receiver-operating characteristic (ROC) analysis was used to distinguish these alterations in SCD and aMCI.

RESULTS

The SCD and aMCI groups showed both decreased ReHo in the right middle temporal gyrus (MTG) and decreased GMV compared to healthy controls (HCs). Especially in the SCD group, there were increased fALFF and increased ReHo in the left inferior occipital gyrus (IOG), decreased fALFF and increased FC in the left inferior parietal lobule (IPL), and reduced cortical thickness in the right inferior temporal gyrus (ITG). Furthermore, functional and structural alterations in the SCD and aMCI groups were closely related to episodic memory (EM), executive function (EF), and information processing speed (IPS). The combination of multiple indicators of DAN had a high accuracy in differentiating clinical stages.

CONCLUSIONS

Our current study demonstrated functional and structural alterations of DAN in SCD and aMCI, especially in the MTG, IPL, and SPL. Furthermore, cognitive performance was closely related to these significant alterations. Our study further suggested that the combined multiple indicators of DAN could be acted as the latent neuroimaging markers of preclinical and early-stage AD for their high diagnostic value.

Attentional Control in Subjective Cognitive Decline

BACKGROUND

Attention is an essential cognitive ability that is necessary in other cognitive processes. Only few studies have focused on decline in specific functions of attention in older adults with cognitive decline. No research explores the difference in the proactive and reactive mode of control between the healthy control (HC) and older adults with subjective cognitive decline (SCD).

OBJECTIVE

The current work investigated whether there was any decline in alerting, orienting, and executive control in SCD. Particularly, the present study further explored the impairment of the proactive and reactive control in SCD.

METHODS

We recruited 25 HC and 26 SCD. All participants first finished a set of neuropsychological assessments. They then completed an Attention Network Test for measuring the alerting, orienting, and executive control, the List-wide and the Item-specific Proportion Congruency Effect task for measuring the proactive and reactive mode of control, respectively.

RESULTS

No difference was found in alerting, orienting, and executive control measured by the ANT between SCD and HC. The results also indicated no difference in the reactive control between SCD and HC. However, older adults with SCD performed worse in the proactive control as compared to HC.

CONCLUSION

Older adults with SCD showed an impairment in the proactive control. The current findings help us better understand objective decline in cognitive domains other than memory and shed light on early assessment and prevention of AD.

Associated factors of new subjective cognitive decline complaints after a 6-month period among community-dwelling older adults during the COVID-19 pandemic in Japan

BACKGROUND

The aim of this study was to determine the number of new subjective cognitive decline (SCD) complaints and associated factors in community-dwelling older adults during the COVID-19 pandemic in Japan.

METHOD

A prospective cohort study was conducted in two periods: May to June 2020, and November 2020 to January 2021. We mailed a questionnaire to 1953 older adults in the first survey, and received 700 responses in the second. We analysed 534 participants without SCD in the first survey. We collected data on sociodemographic characteristics and administered the Questionnaire for Medical Checkup of Old-Old (QMCOO) to assess respondents' health condition. SCD was operationally defined using the QMCOO as reports of (1) forgetfulness, and (2) difficulty in naming dates. The subjects were divided into two groups by their condition at the second survey: an SCD (new SCD complaints) and a no-SCD (no new SCD complaints) group.

RESULTS

A total of 85 (15.9%) participants had new SCD complaints. The Mann-Whitney U-test and chi-squared test showed that the SCD group had significantly more risk factors of SCD: walking speed (P = 0.001), smoking (P = 0.001), and existence of person with whom the patient could consult when disordered (P = 0.002). Multiple logistic regression analysis revealed that walking speed (odds ratio (OR) = 2.115, 95% confidence interval (CI): 1.259-3.553) and the presence of person to consult (OR = 3.619, 95% CI: 1.553-8.433) were significant related factors of new SCD complaints.

CONCLUSION

Maintenance of physical condition and social support were associated with new SCD complaints during the COVID-19 pandemic.

Association between Sleep Onset Problem and Subjective Cognitive Complaints among Japanese Older Adults during the Coronavirus Disease 2019 Pandemic

Older adults are more likely to have age-related sleep problems, which may result in the reduction of cognitive functions. This study was designed to examine the relationship between sleep onset problem and subjective cognitive complaints (SCC) among community-dwelling older adults during the coronavirus disease 2019 pandemic. In this study, 186 older adults aged 65 and above were enrolled and were instructed to respond to an online survey. This survey comprised questions regarding sleep quality (four items such as sleep duration, use of sleep medication), SCC (six domains), and sociodemographic information (eight items such as age, gender, stress condition). We classified the participants into two groups according to the presence or absence of sleep onset problem and examined the relationship between each SCC domain. The sleep onset problem (+) (n = 70) group had significantly higher frequency of scheduled memory decline, misplacement, disorientation in time, word recall decline, and forgetfulness. Furthermore, the sleep onset problem affected the participants' scheduled memory after adjusted for potential covariates (OR, 2.28; 95%CI, 1.13-4.73; p = 0.02). Older adults with sleep onset problem may need to be evaluated for SCC and supported in term of both sleep status and SCC.

Association of physical fitness with cognitive function in the community-dwelling older adults

Background

Cognitive function generally declines with the aging process. Although the association of physical fitness with cognitive function has been proved, how many and how well the physical fitness components are linked to cognitive function is not clear. This study aimed to examine the association of physical fitness with cognitive function, and find out which aspects of physical fitness components are the most closely related to cognitive function in community-dwelling older adults.

Methods

This cross-sectional study was conducted from March to July 2019. The sample consisted of 107 older people in the community with a mean age of 71.7 ± 5.0 years. The cognitive function of the participants was measured by a Chinese version of the Mini-Mental State Examination (MMSE). Several physical fitness items including grip strength, 5-repetition sit-to-stand, timed up and go, sit and reach, one-leg balance with the eye open, and 6-min walk were measured to reflect muscle strength, muscle endurance, agility, flexibility, balance, and cardiopulmonary endurance, respectively.

Results

The correlation analysis showed that the grip strength and the 6-min walk were positively related to cognitive function (r = 0.42 and 0.35, P < 0.05), while the 5-repetition sit-to-stand was negatively associated with cognitive function (r = -0.43, P < 0.01) adjusting for sex, age and years of education. It was also found that the mean values of physical fitness items including grip strength and 6-min walk were significantly lower, and 5-repetition sit-to-stand and timed up and go were significantly greater in the older adults with cognitive impairment (MMSE score < 27) than those in the normal older adults (MMSE score ≥ 27) (P < 0.05). Stepwise regression analysis revealed that age, together with physical fitness items including grip strength and 6-min walk can explain the cognitive function in older adults.

Conclusion

The findings suggest that there is an association between physical fitness and cognitive function, and the grip strength and 6-min walk can help explain the cognitive function in community-dwelling older adults. More attention needs to be paid to the increase in physical fitness for preventing or improving the cognitive dysfunction of older persons in the community, and further longitudinal study is warranted.

Apathy co-occurs with subjective cognitive decline among community-dwelling older adults

OBJECTIVE

To investigate the relationship between apathy and subjective cognitive decline (SCD) in community-dwelling older adults.

METHODS

A total of 211 participants without objective cognitive impairment were included in this study. Their SCD, apathy, sleep quality, depression, and anxiety were assessed by face-to-face interviews. Multivariate logistic regression was constructed to examine the independent relationship between apathy and SCD with adjustment for confounders.

RESULTS

The participants' average SCD-questionnaire and apathy evaluation scale-self scores were 7.13 and 30.65, respectively. Nearly half of the participants were categorized as having SCD. A quarter of participants were identified as apathetic. The apathy score was significantly associated with an increased risk of SCD (odds ratio 1.05, 95% confidence interval 1.01-1.10) after controlling for covariates.

CONCLUSION

Apathy was independently and significantly associated with SCD in community-dwelling older adults without objective cognitive impairment. Thus early intervention on apathy is important to protect elderly cognitive functioning.

An application study-subjective cognitive decline Questionnaire9 in detecting mild cognitive impairment (MCI)

Objective: Subjective cognitive decline (SCD) complaints as the early manifestation of mild cognitive impairment (MCI) may be harbingers of objective cognitive decline. SCD-questinnaire9 (SCD-Q9) is developed to investigate the early sign for MCI. However, few studies have reported its power for discriminating MCI from healthy controls (HCs). Therefore, this study aims to investigate the discrimination power of SCD-Q9 as a brief screening tool for early detection of SCD in MCI.Methods: 84 HCs and 205 people with MCI were recruited. Their demographic information and scores of SCD-Q9 were compared. A binary logistic regression model was used to analyze the potential affecting factors of MCI, and the Receiver Operating Characteristic analysis was applied to test the discrimination powers of those factors, including SCD-Q9.Results: (1) Single and total scores of SCD-Q9 were all lower in the MCI group than those in the HC group. (2) Ageing, lower education and higher total scores of SCD-Q9 were associated with MCI. (3) Area Under the Curves (AUC) of SCD-Q9 for discriminating MCI from HC group was 0.815 and when integrating age and education, the AUC improved slightly and reached 0.839. Additionally, the sensitivity and specificity were 68.8% and 85.7%, respectively when a cut-off value of 3 was applied. Conclusions: SCD-Q9 may be able to detect the subjective cognitive decline in MCI early, but it may be used together with other screening questionnaires to improve its sensitivity and further verification of its power is needed.

The characteristics of arterial spin labeling cerebral blood flow in patients with subjective cognitive decline: The Chinese imaging, biomarkers, and lifestyle study

Objective

We aimed to characterize the potential risk factors and cerebral perfusion of patients with subjective cognitive decline (SCD).

Methods

This prospective study enrolled consecutive patients from the Chinese Imaging, Biomarkers, and Lifestyle (CIBL) Cohort of Alzheimer’s disease between February 2021 and March 2022. Patients who met the SCD diagnostic criteria were categorized into the SCD group, while those without cognitive complaints or any concerns were assigned to the healthy control (HC) group. The demographic and clinical characteristics and cerebral blood flow (CBF) from pseudo-continuous arterial spin labeling (pCASL) in standard cognitive regions were compared between these two groups. A multivariate analysis was performed to identify independent factors associated with SCD.

Results

The frequency of family history of dementia in the SCD group was higher compared with the HC group (p = 0.016). The CBF of left hippocampus (p = 0.023), left parahippocampal gyrus (p = 0.004), left precuneus (p = 0.029), left middle temporal gyrus (p = 0.022), right parahippocampal gyrus (p = 0.018), and right precuneus (p = 0.024) in the SCD group were significantly increased than those in the HC group. The multivariate logistic regression analyses demonstrated that the family history of dementia [OR = 4.284 (1.096–16.747), p = 0.036] and the CBF of left parahippocampal gyrus [OR = 1.361 (1.006–1.840), p = 0.045] were independently associated with SCD.

Conclusion

This study demonstrated that the family history of dementia and the higher CBF within the left parahippocampal gyrus were independent risk factors associated with patients with SCD, which could help in the early identification of the SCD and in intervening during this optimal period.

Association of Playing Cards or Mahjong with Cognitive Function in Chinese Older Adults

Cognitive decline in older adults is a major public health threat. This study aimed to explore the association of participation in cards or mahjong with cognitive function in older adults. A total of 7308 older adults were selected from the 2018 Chinese Longitudinal Healthy Longevity Survey. A modified Mini-Mental State Examination (MMSE) was used to assess cognitive function. The participants were classified according to the frequency of playing cards or mahjong into the “regularly” (R) group, “occasionally” (O) group, or “never” (N) group. The results showed that older persons in the R group and O group had better cognitive function than those in the N group. Specifically, significant differences were found in attention and calculation, language, and total MMSE score between the R group and the N group. However, significant differences were not observed for adults aged 60–69 years old. Regression analysis indicated that playing cards or mahjong, together with age, educational level, sex, marital status, and occupation before age 60 could explain the cognitive function. The findings suggest that there is an association between participation in cards or mahjong and cognitive function in the population of Chinese older adults, and that the frequency of participation plays an important role in the association.

Cross-Cultural Longitudinal Study on Cognitive Decline (CLoCODE) for Subjective Cognitive Decline in China and Germany: A Protocol for Study Design

Background: Subjective cognitive decline (SCD) is considered as the first symptomatic manifestation of Alzheimer’s disease (AD), which is also affected by different cultural backgrounds. Establishing cross-cultural prediction models of SCD is challenging. Objective: To establish prediction models of SCD available for both the Chinese and European populations. Methods: In this project, 330 SCD from China and 380 SCD from Germany are intended to be recruited. For all participants, standardized assessments, including clinical, neuropsychological, apolipoprotein E (APOE) genotype, blood, and multi-parameter magnetic resonance imaging (MRI) at baseline will be conducted. Participants will voluntarily undergo amyloid positron emission tomography (PET) and are classified into amyloid-β (Aβ) positive SCD (SCD+) and Aβ negative SCD (SCD-). First, baseline data of all SCD individuals between the two cohorts will be compared. Then, key features associated with brain amyloidosis will be extracted in SCD+ individuals, and the diagnosis model will be established using the radiomics method. Finally, the follow-up visits will be conducted every 12 months and the primary outcome is the conversion to mild cognitive impairment or dementia. After a 4-year follow-up, we will extract factors associated with the conversion risk of SCD using Cox regression analysis. Results: At present, 141 SCD from China and 338 SCD from Germany have been recruited. Initial analysis showed significant differences in demographic information, neuropsychological tests, and regional brain atrophy in SCD compared with controls in both cohorts. Conclusion: This project may be of great value for future implications of SCD studies in different cultural backgrounds. Trial registration: ClinicalTrials.gov, NCT04696315. Registered 3 January 2021.

U-shaped association between sleep duration and subjective cognitive complaints in Chinese elderly: a cross-sectional study

BACKGROUND

Subjective cognitive decline (SCD) may be the early screening signal to distinguish susceptible population with Alzheimer's disease (AD) and mild cognitive impairment (MCI). Subjective cognitive complaints (SCCs) have been proved strongly associated with SCD. This study aimed to explore the association between sleep duration and SCCs in the Chinese elderly.

METHODS

We conducted a cross-sectional study involving 688 participants aged 60 years and older in Guangdong Province, China. SCCs were assessed by the Subjective Cognitive Decline questionnaire 9 (SCD-Q9), which contained 9 items with two dimensions, including the overall memory function and time comparison (OMTC) and daily activity ability (DAA). Restricted cubic splines and generalized additive model (GAM) were used to fit the association between sleep duration and SCD-Q9 score.

RESULTS

There were significant U-shaped associations between sleep duration and overall score of SCD-Q9 (EDF = 3.842, P < 0.001), as well as the OMTC dimension (EDF = 4.471, P < 0.001) in the age- and gender-adjusted GAM. The lowest points on the overall score of SCD-Q9 and OMTC score were observed in those sleeping 8 h per night. After further adjusting for other demographic characteristics, lifestyle behaviors, hypertension and diabetes, the U-shaped associations between sleep duration and the overall score of SCD-Q9 (EDF = 3.575, P = 0.004), sleep duration and the OMTC score (EDF = 4.478, P = 0.010) were still found. The daily activity ability (DAA) score was also non-linear associated with sleep duration both in the age- and gender-adjusted GAM (EDF = 2.314, P < 0.001) and further adjusted GAM (EDF = 2.080, P = 0.010).

CONCLUSIONS

Both longer sleep duration (> 8 h) and shorter duration (< 8 h) were linked to worse SCCs. Future studies should explore the protective effect of managing sleep duration on SCD and its progression to dementia.

Subjective cognitive decline symptoms and its association with socio-demographic characteristics and common chronic diseases in the southern Chinese older adults

Background

Subjective cognitive decline (SCD) may be the first symptomatic manifestation of Alzheimer’s disease, but information on its health correlates is still sparse in Chinese older adults. This study aimed to estimate SCD symptoms and its association with socio-demographic characteristics, common chronic diseases among southern Chinese older adults.

Methods

Participants aged 60 years and older from 7 communities and 2 nursing homes in Guangzhou were recruited and interviewed with standardized assessment tools. Pittsburgh Sleep Quality Index (PSQI), Patient Health Questionnaire–9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7) were used to measure poor sleep quality, depression symptoms and anxiety symptoms. The SCD symptoms were measured by SCD questionnaire 9 (SCD-Q9) which ranged from 0 to 9 points, with a higher score indicating increased severity of the SCD. Participants were divided into low score group (SCD-Q9 score ≤ 3) and higher score group (SCD-Q9 score > 3). Chi-square tests and multivariate logistic regression analysis were used for exploring the influences of different characteristics of socio-demographic and lifestyle factors on SCD symptoms. Univariate and multivariate logistic regression analysis were applied to explore the association between SCD symptoms with common chronic diseases.

Results

A total of 688 participants were included in our analysis with a mean age of 73.79 (SD = 8.28, range: 60–101), while 62.4% of the participants were females. The mean score of the SCD-Q9 was 3.81 ± 2.42 in the whole sample. A total of 286 participants (41.6%) were defined as the low score group (≤3 points), while 402 participants (58.4%) were the high score group (> 3 points). Multivariate logistic regression analysis revealed that female (OR = 1.99, 95%CI: 1.35–2.93), primary or lower education level (OR = 2.58, 95%CI: 1.38–4.83), nursing home (OR = 1.90, 95%CI: 1.18–3.05), napping habits (OR = 1.59, 95%CI: 1.06–2.40), urolithiasis (OR = 2.72, 95%CI: 1.15–6.40), gout (OR = 2.12, 95%CI: 1.14–3.93), poor sleep quality (OR = 1.93, 95%CI: 1.38–2.71), depression symptoms (OR = 3.01, 95%CI: 1.70–5.34) and anxiety symptoms (OR = 3.11, 95%CI: 1.29–7.46) were independent positive related to high SCD-Q9 score. On the other hand, tea-drinking habits (OR = 0.64, 95%CI: 0.45–0.92), current smoking (OR = 0.46, 95%CI: 0.24–0.90) were independent negative related to high SCD-Q9 score.

Conclusions

Worse SCD symptoms were closely related to common chronic diseases and socio-demographic characteristics. Disease managers should pay more attention to those factors to early intervention and management for SCD symptoms among southern Chinese older adults.

Difference in Amyloid Load Between Single Memory Domain and Multidomain Subjective Cognitive Decline: A Study from the SILCODE

Background: Subjective cognitive decline (SCD), an at-risk condition of Alzheimer’s disease (AD), can involve various cognitive domains, such as memory, language, planning, and attention. Objective: We aims to explore the differences in amyloid load between the single memory domain SCD (sd-SCD) and the multidomain SCD (md-SCD) and assess the relationship of amyloid pathology with quantitative SCD scores and objective cognition. Methods: A total of 63 SCD participants from the SILCODE study underwent the clinical evaluation, neuropsychological assessment, and 18F-florbetapir PET scan. Global amyloid standard uptake value ratio (SUVr) was calculated. Additionally, regional amyloid SUVr was quantified in 12 brain regions of interests. A nonparametric rank ANCOVA was used to compare the global and regional amyloid SUVr between the md-SCD (n = 34) and sd-SCD (n = 29) groups. A multiple linear regression analysis was conducted to test the relationship of amyloid SUVr with quantitative SCD scores and objective cognition. Results: Compared with individuals with sd-SCD, individuals with md-SCD had increased global amyloid SUVr (F = 5.033, p = 0.029) and regional amyloid SUVr in the left middle temporal gyrus (F = 12.309, p = 0.001; Bonferroni corrected), after controlling for the effects of age, sex, and education. When pooling all SCD participants together, the increased global amyloid SUVr was related with higher SCD-plus sum scores and lower Auditory Verbal Learning Test-delayed recall scores. Conclusion: According to our findings, individuals with md-SCD showed higher amyloid accumulation than individuals with sd-SCD, suggesting that md-SCD may experience a more advanced stage of SCD. Additionally, increased global amyloid load was predictive of a poorer episodic memory function in SCD individuals.

The role of depression and anxiety in the relationship between poor sleep quality and subjective cognitive decline in Chinese elderly: Exploring parallel, serial, and moderated mediation

BACKGROUND

Poor sleep quality exacerbates subjective cognitive decline (SCD). Mental health may play an important role in the relationship, but the potential underlying mechanisms remain unknown.

METHODS

A cross-sectional study was conducted on older adult residents in Guangdong province, south China from November 2020 to March 2021. A total of 717 adults aged 60 years and over were recruited for a face-to-face investigation on a range of socio-demographic factors, lifestyle behaviors, sleep quality, SCD, depressive and anxiety symptoms. Parallel, serial and moderated mediation models were used to examine whether depression and anxiety mediated in the poor sleep quality-SCD linkage.

RESULTS

Both direct and indirect effects of poor sleep quality on SCD symptoms were found. Anxiety and depressive symptoms mediated the relationship between poor sleep quality and SCD symptoms(β_Anxiety = 0.123, 95%CI: 0.079 to 0.173; β_Depression=0.274, 95%CI: 0.200 to 0.348), respectively. Serial mediation analyses indicated that depressive and anxiety symptoms co-play a serial mediating role in the association of poor sleep quality and SCD symptoms (β_a=0.052, 95% CI: 0.026 to 0.084; β_b=0.077, 95% CI: 0.033 to 0.128). Moderated mediation model revealed that the mediation of depressive symptoms on the relationship between poor sleep quality and SCD symptoms was moderated by anxiety symptoms(β=0.318, 95% CI: 0.164 to 0.472).

LIMITATIONS

The study is the cross-sectional design, which limits the causal inference ability.

CONCLUSIONS

These findings provided new insights into possible avenues for prevention and intervention on SCD through sleep-based treatments with a multi-faceted approach on psychiatric disorders.

Influencing Factors of Subjective Cognitive Impairment in Middle-Aged and Older Adults

The purpose of this study was to identify the factors affecting subjective cognitive impairment. We analyzed data from the 2019 Korea Community Health Survey and enrolled 68,546 middle-aged adults, aged 50 to 64 years, and 74,547 older adults, aged 65 years and older, in this study. Multiple logistic regression analysis was performed to identify factors influencing subjective cognitive impairment. Of the participants, 11,926 (17.4%) middle-aged and 21,880 (29.4%) older adults living in the community reported subjective cognitive impairment. Major factors that influenced subjective cognitive impairment in both middle-aged and older adults were gender, subjective stress, depressive symptoms, and alcohol drinking. In contrast to middle-aged adults, the marital status of older adults affected subjective cognitive impairment. Therefore, the factors affecting subjective cognitive impairment in middle-aged and older adults need to be considered for screening and management to prevent cognitive impairment and dementia. In particular, it is necessary to evaluate and manage stress and depressive symptoms from middle age to prevent subjective cognitive impairment.

The Association between Social Support and Cognitive Impairment among the Urban Elderly in Jinan, China

China is currently facing a severe challenge of population ageing. However, no study has specifically explored the association between social support and cognitive impairment in Chinese urban elderly aged 60 and older. We explored the prevalence of cognitive impairment and its relationship with social support among the urban elderly aged above 60 years in Jinan, China. A total of 522 urban elderly individuals were recruited using multi-stage cluster random sampling, of which 35.55% were males and 64.45% were females. The average age of all participants was 69.66 ± 8.91 years old. Social support was assessed using the Social Support Rating Scale. Cognitive status was assessed using the Mini-Mental State Examination. Data were collected through face-to-face interviews using structured questionnaires. Descriptive analysis, chi-square tests, and logistic regression analyses were conducted. After analysing the data from 512 participants, 154 (30.1%), 352 (68.8%), and 6 (1.2%) participants had high, moderate, and low levels of social support, respectively. In addition, 125 participants (24.4%) had a cognitive impairment, while the other 387 participants (75.6%) had a normal cognitive status. Binary logistic regression analyses showed that age, educational level, occupation or pre-retirement occupation, and social support were statistically associated with cognitive impairment. A significant association between social support and cognitive impairment was found among the urban elderly in Jinan, China, which provided useful information for the intervention of cognitive impairment. More attention should be paid to the social support of the urban elderly to effectively reduce the occurrence of cognitive impairment.

Gender differences in cognitive reserve: implication for subjective cognitive decline in women

Background

Subjective Cognitive Decline (SCD) is a self-experienced decline in cognitive capacity with normal performance on standardized cognitive tests, showing to increase risk of Alzheimer’s Disease (AD). Cognitive reserve seems to influence the progression from SCD to Mild Cognitive Impairment (MCI) and to AD. The aim of our study was to investigate gender differences in cognitive reserve evaluating how sex might modulate the role of cognitive reserve on SCD.

Methods

We included 381 SCD patients who underwent clinical evaluation, neuropsychological assessment, evaluation of premorbid intelligence by the Test di Intelligenza Breve (TIB), cognitive complaints by the Memory Assessment Clinics Questionnaire (MAC-Q), and apolipoprotein E (APOE) genotyping.

Results

The proportion between women and men was significantly different (68.7% [95% CI 63.9–73.4 vs 31.4%, 95% CI 26.6–36.0]). Women were younger than men at onset of SCD and at the baseline visit (p = 0.021), had lower years of education (p = 0.007), lower TIB scores (p < 0.001), and higher MAC-Q scores (p = 0.012). TIB was directly associated with age at onset of SCD in both women and men, while years of education was inversely associated with age at onset only in women. Multivariate analysis showed that sex influences TIB independently from years of education. TIB was directly associated with MAC-Q in men.

Conclusions

Sex interacts with premorbid intelligence and education level in influencing the age at onset and the severity of SCD. As the effect of education was different between men and women, we speculated that education might act as a minor contributor of cognitive reserve in women.

Effects of Aerobic Dance on Cognition in Older Adults with Mild Cognitive Impairment: A Systematic Review and Meta-Analysis

BACKGROUND

Regular aerobic exercises could improve global cognition in older adults with mild cognitive impairment (MCI), such as aerobic dance a type of commonly practiced aerobic exercises. However, its effects remain debatable in improving the cognitive function in patients with MCI.

OBJECTIVE

The aim of this systematic review and meta-analysis is to evaluate the effects of aerobic dance on cognitive function among older adults with MCI.

METHODS

We searched articles in the MEDLINE, PubMed, Embase, and The Cochrane Library databases from inception to 28 February 2019, with the following criteria: 1) randomized controlled trials; 2) older adults with MCI; 3) aerobic dance intervention.

RESULTS

Five studies of 842 participants were identified. This meta-analysis showed that aerobic dance can significantly improve global cognition (Mini-Mental State Examination: MD = 1.43; 95% CI:[0.59, 2.27]; p = 0.0009; Alzheimer's Disease Assessment Scale-Cognitive Subscale: MD=-2.30; 95% CI:[-3.60, -1.00]; p = 0.0005), and delayed recall ability (SMD = 0.46;95% CI: [0.30, 0.62]; p < 0.00001) in older adults with MCI. In addition, have positive effects on improving executive function (Trial-Making Test A: MD = -2.37;95% CI:[-4.16, -0.58]; p = 0.010; Trial-Making Test B: MD = -16.0; 95% CI: [-30.03, -2.11]; p = 0.020) and immediate recall ability (SMD = 0.24;95% CI: [0.01, 0.46]; p = 0.04).

CONCLUSION

Aerobic dance significantly improves global cognitive function and memory in older adults with MCI. In addition, it also benefits executive function. However, due to the limitations as the review states, more randomized controlled trials with better study design and larger sample sizes should be conducted in the future research to make it much clearer.

Effects of Smartphone-Based Compensatory Cognitive Training and Physical Activity on Cognition, Depression, and Self-Esteem in Women with Subjective Cognitive Decline

Subjective cognitive decline is a symptom that may appear in the early stages of Alzheimer’s disease. This study examined the effects of smartphone-based calendar training and walking exercise regimen on postmenopausal women experiencing subjective cognitive decline. Experimental group 1 participated in both calendar training and walking exercise, group 2 participated in calendar training only, and the control group did not receive either intervention. Forty-two participants completed a cognitive function test and questionnaire upon entering the study and 12 weeks later. The controlled oral word association score increased in experimental groups 1 and 2 and decreased in the control group. Memory contentment increased in experimental group 1, maintained in experimental group 2, and decreased in the control group. Smartphone-based calendar training and a walking exercise regimen improved executive function and memory contentment in everyday life, but the effects on depressive symptoms and self-esteem were not significant. Our findings demonstrate that smartphone-based calendar training and walking exercise improved cognitive function and have potential as nonpharmacologic interventions to strengthen cognitive function in women experiencing subjective cognitive decline.

Evidence of Effect of Aerobic Exercise on Cognitive Intervention in Older Adults With Mild Cognitive Impairment

This study aimed to evaluate the effectiveness of aerobic exercise as a cognitive intervention for older adults with mild cognitive impairment (MCI). The PubMed, EMBASE (Ovid), Cochrane Library, Web of Science, and Medline databases were searched from their inception until 30 April 2021. Randomized controlled trials (RCTs) examining the effects of aerobic exercise on global cognitive function in older adults with MCI were included. Ten eligible trials with acceptable methodological quality were identified. The meta-analysis results showed that aerobic exercise significantly improved the MMSE (N = 956, MD = 0.60, 95% CI: 0.28-0.92, p = 0.0003, I 2 = 31%, fixed effects model) and MoCA scores (N = 398, MD = 1.67, 95% CI. 1.18-2.15, p < 0.0001, I 2 = 37%, fixed-effects model) and overall cognitive performance in patients with MCI. The results of this study suggest that participation in regular aerobic exercise can improve cognitive function in older adults with MCI. These findings should be used with caution considering the limitations of the study.

Factors influencing subjective cognitive function among community-dwelling older adults

BACKGROUND

Subjective cognitive decline (SCD) is one of the most common complaints in older adults and may increase risk factors for dementia. Therefore, it is important to identify and manage risk factors for subjective cognitive function (SCF).

PURPOSE

This study aimed to investigate factors influencing SCF in community-dwelling older adults.

METHODS

With a cross-sectional research design, 164 older adults responded to questionnaires. Data were analyzed using descriptive statistics, independent t-test, one-way ANOVA, Scheffé-test, Pearson's correlation coefficient, and multiple regression with SPSS 23.0.

RESULTS

Participating in religious activities, sleeping well, a lower number of comorbidities, better perceived health status, lower depression, and higher self-esteem were associated with better SCF. Overall, approximately 24.9% of the variability in SCF was explained by perceived health status, religion, and depression.

CONCLUSION

Multifaceted aspects must be considered when developing interventions to improve SCF in community-dwelling older adults who complain of experiencing SCD.

Older Adults' Subjective Cognitive Decline Correlated with Subjective but Not Objective Sleep: A Mediator Role of Depression

This study examined the relationship between older adults' subjective versus objective sleep and subjective cognitive decline (SCD), and explored the role of depression on this association. One hundred and four community-dwelling older adults underwent a week of actigraphic sleep monitoring, and completed a series of neuropsychological screeners. Older adults'SCD score was positively correlated with subjective insomnia, but not with objective sleep parameters. Further mediation modeling revealed that older adults'depression mediated the association between subjective insomnia and SCD. Subjective sleep, rather than objective sleep, may be a more sensitive indicator for older adults' SCD, with depression symptoms appearing to account for most of the variance. These findings extend our perspective on the relationship between sleep disruption and cognitive decline, and highlight the necessity of early targeted interventions on sleep to reduce the risk of cognitive impairment in the elderly with SCD.

The Impact of Study Setting on Clinical Characteristics in Older Chinese Adults with Subjective Cognitive Decline: Baseline Investigation of Convenience and Population-Based Samples

Background

Subjective cognitive decline (SCD) is the earliest symptom stage of Alzheimer's disease (AD). Previous studies have shown that the study setting is an important influence factor of SCD. However, the effect of this factor among a Chinese population with SCD is not clear. Here, we aim to compare the clinical characteristics of SCD between a convenience and a population-based sample in China.

Methods

We included a convenience sample of 212 SCD subjects and a population-based sample of 110 SCD subjects. We performed univariate analysis to evaluate the between-group differences in sociodemographic characteristics, neuropsychological performance, psychiatric conditions, different cognitive domains, and the SCD-plus criteria. Multiple linear regression model was established, adjusted for sex, age, and education, and compared the neuropsychological performance between the groups.

Results

The convenience sample had more years of education, a higher family history of dementia, and higher neuropsychological and anxiety depression score than the population-based sample. Using sex, age, education, group as the independent variables, and neuropsychological score as the dependent variable, multiple linear regression model was established; a statistically significant neuropsychological score difference (MoCA-B, AVLT-H-N4, AVLT-H-N5, AVLT-H-N7, AFT, and STT-B) was found between the two samples. In the SCD cognitive domains, the population-based sample had more complaints about declines in their language and planning domains. For SCD-plus criteria in memory domain, the convenience sample had more complaints, worry, and cognitive decline within the last 5 years, along with medical help-seeking.

Conclusion

There were some different characteristics among SCD individuals between convenience samples and population-based samples in China.

Demographic characteristics and neuropsychological assessments of subjective cognitive decline (SCD) (plus)

BACKGROUND

Since SCD (plus) was standardized, little is known about its demographic characteristics and its outcomes of neuropsychological assessments, including the SCD questionnaire 9 (SCD-Q9).

OBJECTIVE

To characterize SCD (plus) by comparing the neuropsychological features among its subgroups and with normal controls (NC). Also, to explore its demographics and to understand the relation of the chief complaints and the scores of SCD-Q9.

METHODS

Multistage stratified cluster random sampling was conducted to select participants. As a result, 84 NC and 517 SCD (plus) were included. SCD (plus) was further classified into several subgroups (SCD-C: concerned cognitive decline; SCD-F: complaints about SCD within the past five years; SCD-P: feeling performance being not as good as their peers; SCD+: presented> 3 of SCD (plus) features; SCD-: presented ≤ 3 of SCD (plus) features (see the diagnostic criteria for the details)) and between-group comparisons of neuropsychological scores were conducted. Point-biserial correlation and binary logistic regression analyses were performed to investigate the demographic characteristics of its subgroups. Finally, Spearman correlation was used to better understand the relation of SCD (plus) to SCD-Q9.

RESULTS

(1) Scores of AVLT-LR (AVLT-LR: Auditory Verbal Learning Test-Long Delayed Recall) and MoCA-B (MoCA: Montreal Cognitive Assessment-Basic) were lower in the SCD-P group than those in the NC group, and the SCD+ group scored lower in the MoCA-B and CDT(CDT: Clock Drawing Test) than the SCD- group. (2) Females were more concerned than male participants. Individuals with lower education level felt that their cognitive performance were worse than their peers. Also, younger people might express concerns more than the more elderly. People who had complaints of SCD-P might be more likely to report SCD-C, but less likely to report SCD-F. (3) Positive correlations were found between the chief complaints of SCD (plus) and some items of SCD-Q9.

CONCLUSIONS

SCD (plus) may be related to demographic factors. Individuals with SCD (plus) already exhibited cognitive impairment, which can be detected by SCD-Q9.

Metabolic syndrome, ApoE genotype, and cognitive dysfunction in an elderly population: A single-center, case-control study

BACKGROUND

Metabolic syndrome (MetS) is related to poor cognitive function. However, the results of previous studies were inconsistent, and whether the ApoEε4 allele modifies the association remains unclear.

AIM

To elucidate the relationships among MetS, ApoEε4, and cognitive dysfunction in an elderly population in China.

METHODS

One hundred elderly patients with MetS and 102 age- and gender-matched controls were included in the study. Baseline clinical characteristics and biochemical index for glucose and lipid metabolism were obtained. The distribution of ApoEε4 was assessed with PCR restriction fragment length polymorphism analysis. Cognitive function was evaluated by mini-mental status examination at the 1-year follow-up examination.

RESULTS

Compared with controls, MetS patients had worse cognitive function and decreased ability to participate in activities of daily life (P = 0.001 and 0.046, respectively). Patients with cognitive dysfunction had higher prevalence of MetS (62.1% vs 36.4%, P < 0.001) and were more likely to carry the ApoEε4 allele (22.3% vs 10.1%, P = 0.019). Multivariate logistic regression analyses showed that diagnosis with MetS, severe insulin resistance, status as an ApoEε4 carrier, higher systolic blood pressure, and larger waist circumference were risk factors for cognitive dysfunction (P < 0.05). Repeated-measures analysis of variance, performed with data collected at the 1-year follow-up, revealed continuous influences of MetS and ApoEε4 on the deterioration of cognitive function (time × team, P < 0.001 for both).

CONCLUSION

Diagnosis of MetS and ApoEε4 carrier status were persistently associated with cognitive dysfunction among an elderly population in China.

Altered Insular Subregional Connectivity Associated With Cognitions for Distinguishing the Spectrum of Pre-clinical Alzheimer's Disease

Background: Subjective cognitive decline (SCD) and amnestic mild cognitive impairment (aMCI) are regarded as part of the pre-clinical Alzheimer's disease (AD) spectrum. The insular subregional networks are thought to have diverse intrinsic connectivity patterns that are involved in cognitive and emotional processing. We set out to investigate convergent and divergent altered connectivity patterns of the insular subregions across the spectrum of pre-clinical AD and evaluated how well these patterns can differentiate the pre-clinical AD spectrum.

Method: Functional connectivity (FC) analyses in insular subnetworks were carried out among 38 patients with SCD, 56 patients with aMCI, and 55 normal controls (CNs). Logistic regression analyses were used to construct models for aMCI and CN, as well as SCD and CN classification. Finally, we conducted correlation analyses to measure the relationship between FCs of altered insular subnetworks and cognition.

Results: Patients with SCD presented with reduced FC in the bilateral cerebellum posterior lobe and increased FC in the medial frontal gyrus and the middle temporal gyrus. On the other hand, patients with aMCI largely presented with decreased FC in the bilateral inferior parietal lobule, the cerebellum posterior lobe, and the anterior cingulate cortex, as well as increased FC in the medial and inferior frontal gyrus, and the middle and superior temporal gyrus. Logistic regression analyses indicated that a model composed of FCs among altered insular subnetworks in patients with SCD was able to appropriately classify 83.9% of patients with SCD and CN, with an area under the receiver operating characteristic (ROC) curve (AUC) of 0.876, 81.6% sensitivity, and 81.8% specificity. A model consisting of altered insular subnetwork FCs in patients with aMCI was able to appropriately classify 86.5% of the patients with aMCI and CNs, with an AUC of 0.887, 80.4% sensitivity, and 83.6% specificity. Furthermore, some of the FCs among altered insular subnetworks were significantly correlated with episodic memory and executive function.

Conclusions: Patients with SCD and aMCI are likely to share similar convergent and divergent altered intrinsic FC patterns of insular subnetworks as the pre-clinical AD spectrum, and presented with abnormalities among subnetworks. Based on these abnormalities, individuals can be correctly differentiated in the pre-clinical AD spectrum. These results suggest that alterations in insular subnetworks can be utilized as a potential biomarker to aid in conducting a clinical diagnosis of the spectrum of pre-clinical AD.

Sleep satisfaction and cognitive complaints in Chinese middle-aged and older persons living with HIV: the mediating role of anxiety and fatigue

Middle-aged and older persons living with HIV (PLWH) suffer from sleep distress and cognitive disorders due to HIV infection and aging. We aim to explore the relationship between sleep satisfaction and cognitive complaints, and the mediating role of anxiety and fatigue in this relationship among middle-aged and older PLWH. We used data from a multicenter cross-sectional study in China (Shanghai, Kunming, Nanning, Hengyang, and Changning) conducted in 2017. The data analysis included 435 PLWH aged 45 years and over. Multiple linear regression models showed that worse sleep satisfaction was significantly associated with lower cognitive complaints after controlling for anxiety, fatigue, demographic variables, and clinical variables (β = -0.246, p < 0.01). Both anxiety and fatigue were significant partial mediators in the relationship between sleep satisfaction and cognitive complaints. The serial multiple mediation models of sleep satisfaction-anxiety (M1)-fatigue (M2)-cognitive complaints were supported and the alternative model of sleep satisfaction-fatigue (M2)-anxiety (M1)-cognitive complaints were both supported. Our study indicates that it is important to improve sleep quality to promote cognitive function among Chinese middle-aged and older PLWH. Prevention and treatment programs for sleep satisfaction and cognitive function should include the assessment and reduction of fatigue and anxiety.

Education Exerts Different Effects on Cognition in Individuals with Subjective Cognitive Decline and Cognitive Impairment: A Population-Based Study

BACKGROUND

Education plays a potential important effect on the prevalence and incidence of dementia. However, most of the evidence based on convenience sampling.

OBJECTIVE

To explore effects of education on cognition in individuals with subjective cognitive decline (SCD) and cognitive impairment (CI) from a population-based study.

METHODS

We examined the effect of education on cognition among individuals with SCD (n = 451) and CI (n = 280) from a population-based study. A series of neuropsychological tests of memory, executive, language, and general cognitive function were used to assess the participants.

RESULTS

Multiple regression analyses revealed that education has a positive effect on cognition in both SCD and CI group in the population-based research. Further stratification study showed that the beneficial effect of education remains in the SCD group regardless of the education level, especially in the SCD participants with a low education level. However, that effect of education exists in the CI group with a low education level and disappears in the high education level.

CONCLUSION

These results from a population-based sample suggest that high educational attainment may delay cognitive decline in the individuals with SCD regardless of high or low educational level, and high education only predicts cognition in those in the low educational level in CI group.

Estimating prevalence of subjective cognitive decline in and across international cohort studies of aging: a COSMIC study

Background

Subjective cognitive decline (SCD) is recognized as a risk stage for Alzheimer’s disease (AD) and other dementias, but its prevalence is not well known. We aimed to use uniform criteria to better estimate SCD prevalence across international cohorts.

Methods

We combined individual participant data for 16 cohorts from 15 countries (members of the COSMIC consortium) and used qualitative and quantitative (Item Response Theory/IRT) harmonization techniques to estimate SCD prevalence.

Results

The sample comprised 39,387 cognitively unimpaired individuals above age 60. The prevalence of SCD across studies was around one quarter with both qualitative harmonization/QH (23.8%, 95%CI = 23.3–24.4%) and IRT (25.6%, 95%CI = 25.1–26.1%); however, prevalence estimates varied largely between studies (QH 6.1%, 95%CI = 5.1–7.0%, to 52.7%, 95%CI = 47.4–58.0%; IRT: 7.8%, 95%CI = 6.8–8.9%, to 52.7%, 95%CI = 47.4–58.0%). Across studies, SCD prevalence was higher in men than women, in lower levels of education, in Asian and Black African people compared to White people, in lower- and middle-income countries compared to high-income countries, and in studies conducted in later decades.

Conclusions

SCD is frequent in old age. Having a quarter of older individuals with SCD warrants further investigation of its significance, as a risk stage for AD and other dementias, and of ways to help individuals with SCD who seek medical advice. Moreover, a standardized instrument to measure SCD is needed to overcome the measurement variability currently dominant in the field.

Subjective Cognitive Decline and Related Cognitive Deficits

Since late stage dementia, including Alzheimer's disease (AD), cannot be reversed by any available drugs, there is increasing research interest in the preclinical stage of AD, i.e., subjective cognitive decline (SCD). SCD is characterized by self-perceptive cognitive decline but is difficult to detect using objective tests. At SCD stage, the cognitive deficits can be more easily reversed compared to that of mild cognitive impairment (MCI) and AD only if accurate diagnosis of SCD and early intervention can be developed. In this paper, we review the recent progress of SCD research including current assessment tools, biomarkers, neuroimaging, intervention and expected prognosis, and the potential relevance to traumatic brain injury (TBI)-induced cognitive deficits.

Beneficial Effects of Brain Reserve on Cognition in Individuals with Subjective Cognitive Decline from the SILCODE Study

BACKGROUND

Clinical research has demonstrated that brain reserve (BR) could exert positive effects on cognition for patients with Alzheimer's disease (AD) and mild cognitive impairment (MCI). However, the effects of BR on cognition in individuals with subjective cognitive decline (SCD) are not clear.

OBJECTIVE

To examine cross-sectional effects of BR on cognition in SCD populations.

METHODS

One hundred forty-nine subjects were studied from the Sino Longitudinal Study on Cognitive Decline (SILCODE) study. Head circumference was used as a proxy of BR. Cognition was assessed across four domains (memory, executive, language, and general cognitive functions). Multiple linear regression models were conducted to examine effects of BR on cognitive scores. Furthermore, we addressed the question that whether the degree of self-perception of cognitive decline modified the effect of BR on cognitive performance in SCD subjects.

RESULTS

We found a positive effect of BR on language cognition in subjects with SCD. Furthermore, the positive effect of BR on language cognition survived in SCD participants with a low degree of self-perception of cognitive decline while disappeared in SCD participants with a high degree of self-perception of cognitive decline.

CONCLUSION

This study suggests that BR has the potential to delay or slow down cognitive decline in SCD individuals, especially for mild SCD.

Physical activity for cognitive health: what advice can we give to older adults with subjective cognitive decline and mild cognitive impairment?

Subjective cognitive decline (SCD) and mild cognitive impairment (MCI) are common conditions in older age and are associated with an increased risk of future cognitive decline and dementia. As there is currently no effective pharmacological treatment available for SCD and MCI, modifiable risk factors for cognitive decline and dementia have received increasing attention in the literature as a focus for clinical trials. Physical activity (PA) is one of the strongest protective lifestyle factors. This clinical review aims to highlight the accumulating evidence about the benefits of PA for SCD and MCI. Whilst there is agreement that at least 150 minutes of moderate aerobic PA per week in combination with additional resistance training is necessary to support brain health in people with SCD and MCI, future research is required to help inform specific advice on type of exercise, intensity, “dose” and effective strategies to encourage behavior change.

Prevalence, Incidence, Influence Factors, and Cognitive Characteristics of Amnestic Mild Cognitive Impairment Among Older Adult: A 1-Year Follow-Up Study in China

BACKGROUND

The risk and protective factors of amnestic mild cognitive impairment (aMCI) and its prevalence as well as incidence among old adult in Chinese community are still unclear.

METHODS

We carried out this 1-year longitudinal study to survey a random sample of 3,246 community elders aged 60 and over in China. All subjects were required to complete a comprehensive clinical assessment, physical examination and several neuropsychological tests at baseline and follow-up. What's more, we also collected their lifestyle information by a standardized questionnaire.

RESULTS

We found that the prevalence of aMCI was 17.1%, while the incidence of aMCI among Chinese old adult was 70.57 per 1,000 person-years. By using Cox regression analysis, we found that male sex (p = 0.001, OR = 0.489, 95%CI 0.319~0.751) and reading (p = 0.023, OR = 0.533, 95%CI 0.310~0.917) were protective factors for against aMCI. Old adult who developed aMCI in the future showed multiple cognitive impairments (such as immediate memory, associative learning memory and executive function) in their early stage, and Wechsler's Block Design (p = 0.027, OR = 0.969, 95%CL 0.943~0.996) could predict whether subjects would turn into aMCI in the future.

CONCLUSIONS

The present study suggests that aMCI is a considerable health problem in China. Executive dysfunction may be an indicator of future development of aMCI in the old normal adult.

The factors associated with subjective cognitive decline and cognitive function among older adults

AIMS

To explore the risk factors for subjective cognitive decline and cognitive function among older adults in South Korea.

DESIGN

This study employed a descriptive cross-sectional design.

METHODS

A convenience sample of 182 patients was recruited from a senior welfare center in Seoul. The mean age of the participants was 78.4 years (SD 5.91). Among them, 64.3% were women. The data were collected by a trained research assistant using structured questionnaires from September 2016-February 2017. Demographic characteristics, comorbidities, depression, physical and cognitive activity levels, instrumental activities of daily living, subjective cognitive decline, and cognitive function were assessed. Student's t tests, chi-square tests, and hierarchical multiple regression analyses were used for statistical analyses.

RESULTS

The findings revealed that 37.4% of the participants were not cognitively intact. Depression, perceived health status, and cognitive function were significantly associated with subjective cognitive decline (F = 7.10, p < .001, adjusted R²  = 25.3). Age, educational level, perceived health status, and subjective cognitive decline were significantly related to cognitive function (F = 20.98, p < .001, adjusted R²  = 47.0). After controlling for these variables, cognitive activity was significantly and independently related to cognitive function.

CONCLUSION

The results suggest that for the maintenance of cognitive function, cognitive activity should be encouraged. In addition, older adults who complain of subjective cognitive decline and have risk factors such as depression need therapeutic interventions to prevent actual decrease of cognitive function.

IMPACT

The present findings advance prior knowledge by considering variables such as physical and cognitive activity levels to provide novel evidence that can be used to develop interventions for community-dwelling older adults. Thus, to be effective, nursing interventions must seek to improve cognitive function through intellectual stimulation.