Gender-Specific Incidence and Predictors of Cognitive Impairment among Older Koreans: Findings from a 6-Year Prospective Cohort Study

Umbrella review and Delphi study on modifiable factors for dementia risk reduction

A 2013 systematic review and Delphi consensus study identified 12 modifiable risk and protective factors for dementia, which were subsequently merged into the "LIfestyle for BRAin health" (LIBRA) score. We systematically evaluated whether LIBRA requires revision based on new evidence. To identify modifiable risk and protective factors suitable for dementia risk reduction, we combined an umbrella review of systematic reviews and meta-analyses with a two-round Delphi consensus study. The review of 608 unique primary studies and opinions of 18 experts prioritized six modifiable factors: hearing impairment, social contact, sleep, life course inequalities, atrial fibrillation, and psychological stress. Based on expert ranking, hearing impairment, social contact, and sleep were considered the most suitable candidates for inclusion in updated dementia risk scores. As such, the current study shows that dementia risk scores need systematic updates based on emerging evidence. Future studies will validate the updated LIBRA score in different cohorts. HIGHLIGHTS: An umbrella review was combined with opinions of 18 dementia experts. Various candidate targets for dementia risk reduction were identified. Experts prioritized hearing impairment, social contact, and sleep. Re-assessment of dementia risk scores is encouraged. Future work should evaluate the predictive validity of updated risk scores.

Study on the trajectory of depression among middle-aged and elderly disabled people in China: Based on group-based trajectory model

Background

Previous studies have shown that middle-aged and elderly adults with disabilities are at higher risk for depressive symptoms. However, there are few studies on the long-term trajectories of depressive symptoms in the Chinese middle-aged and elderly disabled population.

Objective

This study aimed to identify the different development trajectories of depressive symptoms and their influencing factors in middle-aged and elderly people with disabilities in China.

Methods

Using data from the China Health and Retirement Longitudinal Study (CHARLS) in 2011, 2013, 2015, and 2018, a longitudinal cohort was formed for the study. A total of 2053 participants underwent at least two measures of depressive symptoms, assessed using the Center for Epidemiological Studies Depression Scale (CES-D10), a depression symptom assessment scale. We constructed a Group-Based Trajectory Model (GBTM) to identify the development trajectory of depressive symptoms in 2053 middle-aged and elderly disabled individuals, screened the potential predictors using lasso regression, and analyzed the factors affecting the development trajectory of depression through multivariate logistic regression.

Results

We identified four depression symptom trajectories throughout the follow-up process: "low depressive symptom group", "worsening depressive symptom group", "relieved depressive symptom group", and "high depressive symptom group". We found that there were differences in basic characteristics among different subgroups of depression trajectory. However, middle-aged and elderly disabled women living in rural areas, with limited ADL or IADL, physical pain, poor self-reported health and self-reported memory, short sleep time, and no relatives and friends to take care of them were the key groups for the prevention and treatment of depressive symptoms.

Conclusion

There is heterogeneity in the trajectories of depressive symptoms in the Chinese middle-aged and elderly disabled population, it is necessary to focus on the characteristics of the trajectories of different subgroups.

Sex-Related Disparities in the Resting State Functional Connectivity of the Locus Coeruelus and Salience Network in Preclinical Alzheimer's Disease

Recent studies have demonstrated the pivotal role of locus coeruleus (LC) and salience network (SN) resting state functional connectivity (rsFC) changes in the early stage of Alzheimer's disease (AD). Moreover, sex has been a crucial point of discussion in understanding AD pathology. We aimed to demonstrate the sex-related disparities in the functional connectivity (FC) of the SN and LC in preclinical AD. A total of 89 cognitively normal patients with evidence of amyloid beta (Aβ) accumulation ([18F] flutemetamol +) were recruited in the study. A seed-to-voxel analysis was conducted to measure the LC and SN rsFC differences between sexes. In addition, sex by Aβ interactive effects on FC values were analyzed with a general linear model. There were statistically significant sex by regional standardized uptake value ratio (SUVR) interactions in the LC FC with the parietal, frontal, and occipital cortices. Moreover, there was a significant sex by global SUVR interaction in the SN FC with the temporal cortex. The findings suggest that there are differential patterns of LC FC and SN FC in males and females with preclinical AD, which interact with regional Aβ deposition.

Cross-Lagged Panel Analysis between Physical Frailty, Cognitive Function, and Falls by Sex

OBJECTIVES

This study investigated the reciprocal longitudinal relationships between physical frailty (PF), cognitive function (CF), and falls among community-dwelling older adults, according to sex. The study proposed hypotheses that present PF and CF will affect the occurrence of falls 2 years later.

DESIGN

Secondary data analysis using the first (T1, 2016-2017) and second (T2, 2018-2019) waves of the Korean Frailty and Aging Cohort Study (KFACS).

SETTING AND PARTICIPANTS

A total of 2318 community-dwelling older adults aged 70-84 years in South Korea; mean (SD) age: 75.72 (3.83) years; 47.7% men.

METHODS

PF and CF were measured with the modified version of the Fried Frailty Phenotype and the Korean version of the Mini-Mental State Examination, respectively. The number of falls were assessed. Multigroup cross-lagged panel analysis was used.

RESULTS

The results showed that relationships between PF, CF, and falls were maintained over time through an autoregressive effect. PF at T1 had a statistically significant longitudinal relationship with fall experience at T2 [standardized regression coefficient (β) = 0.087, 95% CI 0.045-0.129; P < .001], and fall experience at T1 had a significant longitudinal relationship with PF at T2 (β = 0.041, 95% CI 0.006-0.076; P = .020). There was no statistically significant relationship between CF and fall experience. PF and CF had statistically significant reciprocal longitudinal relationships (all P < .001). Based on sex, there was a statistically significant longitudinal relationship between fall experience at T1 and PF at T2 for men only (β = 0.063, 95% CI 0.012-0.114; P = .015).

CONCLUSIONS AND IMPLICATIONS

Findings highlight that health care providers should plan fall prevention programs through early intervention for PF improvement along with improvement and maintenance of CF. Specifically, even if older men are currently healthy and have a low risk of falls, it is important to prevent future fatal PF through prior interventions, such as risk activities attention and concerns about falls.

A prediction model of cognitive impairment risk in elderly illiterate Chinese women

Objective

To establish and validate a targeted model for the prediction of cognitive impairment in elderly illiterate Chinese women.

Methods

1864 participants in the 2011-2014 cohort and 1,060 participants in the 2014-2018 cohort from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) were included in this study. The Chinese version of the Mini-Mental State Examination (MMSE) was used to measure cognitive function. Demographics and lifestyle information were collected to construct a risk prediction model by a restricted cubic spline Cox regression. The discrimination and accuracy of the model were assessed by the area under the curve (AUC) and the concordance index, respectively.

Results

A total of seven critical variables were included in the final prediction model for cognitive impairment risk, including age, MMSE score, waist-to-height ratio (WHtR), psychological score, activities of daily living (ADL), instrumental abilities of daily living (IADL), and frequency of tooth brushing. The internal and external validation AUCs were 0.8 and 0.74, respectively; and the receiver operating characteristic (ROC) curves indicated good performance ability of the constructed model.

Conclusion

A feasible model to explore the factors influencing cognitive impairment in elderly illiterate women in China and to identify the elders at high risk was successfully constructed.

Associations Between Korean Coronary Heart Disease Risk Score and Cognitive Function in Dementia-Free Korean Older Adults

BACKGROUND

Cardiovascular risk is a modifiable factor that can help prevent dementia. Given the dearth of optimal treatment options, managing dementia risk factors is crucial. We examined the association between cardiovascular risk, as measured by the Korean coronary heart disease risk score (KRS), and cognitive function in dementia-free elderly individuals.

METHODS

We enrolled 8,600 individuals (average age: 69.74 years; 5,206 women) who underwent a medical evaluation from the National Health Insurance Service. KRS was calculated using age, sex, blood pressure, lipid profile, diabetes, and smoking status. Cognitive function was evaluated using Korean Dementia Screening Questionnaire-Cognition (KDSQ-C). Scores of ≥ 6 indicated a cognitive decline. Logistic regression analysis was used to estimate the odds ratio (OR) and 95% confidence interval (CI). Weight, height, stroke history, coronary heart disease history, alcohol consumption, and physical activity engagement were adjusted.

RESULTS

The lowest, middle, and highest groups, according to the KRS, were 5,923 (68.9%), 2,343 (27.2%), and 334 (3.9%), respectively. The highest KRS group in all participants exhibited a greater risk of cognitive decline than the lowest KRS group (OR, 1.339; 95% CI, 1.034-1.734; P = 0.027). The highest KRS female group aged 71-75 years old exhibited greater cognitive decline than the corresponding lowest KRS group (OR, 1.595; 95% CI, 1.045-2.434; P = 0.031).

CONCLUSION

Individuals with high cardiovascular risk were associated with poorer cognitive function than those with low risk, especially older women. Cardiovascular risk factors should be carefully managed to promote healthy mental aging in dementia-free elderly individuals.

Marital transition and cognitive function among older adults: the korean Longitudinal Study of Aging (2006-2020)

BACKGROUND

Marital status has been suggested as an associated factor for cognitive impairment. The consequences of marital transitions are still understudied. This study evaluated the influence of marital transitions on cognitive function using longitudinal, nationwide data of Korean older adults.

METHODS

This research comprised a longitudinal sample of older adults aged ≥ 45 years old, drawn from the Korean Longitudinal Study of Aging (2006-2020). Marital transition was determined through the biennial assessment of change in marital status; cognitive function was measured using the Korean version of the Mini-Mental State Examination. We employed general estimating equations to assess the temporal effect of marital transition on cognitive function.

RESULTS

Compared to married individuals, the odds ratios (ORs) of cognitive decline were higher in not married and transitioned out of marriage participants: men (OR 1.32, 95% confidence interval (CI) 0.96-1.82; OR 1.42, 95% CI 0.90-2.24), women (OR 1.21, 95% CI 1.03-1.42; OR 1.20, 95% CI 1.01-1.52), respectively, despite the findings being not statistically significant in men. The participants who transitioned out of marriage over time also showed greater ORs for mild cognitive impairment: men (OR 1.39, 95% CI 0.79-1.87), women (OR 1.33, 95% CI 1.05-1.80), and dementia: men (OR 1.60, 95% CI 0.85-1.99), women: (OR 1.49, 95% CI 1.20-2.19).

CONCLUSION

Marital transition is found to be associated with cognitive function decline. Not-married individuals and those who became divorced or widowed were associated with the risk of cognitive function decline. Particular attention should be paid to these marital transitioned groups.

Assessment of cognitive function among adults aged ≥ 60 years using the Revised Hasegawa Dementia Scale: cross-sectional study, Lao People's Democratic Republic

BACKGROUND

Rapid population ageing remains an important concern for health, social and economics systems; thus, a broader assessment of cognitive decline among adults aged ≥ 60 years is essential. It is important to regularly collect reliable data through validated and affordable methods from people living in different areas and in different circumstances to better understand the significance of this health problem. This study aimed to identify the prevalence of cognitive impairment and the related risk factors by reassessing the scoring of the Revised Hasegawa Dementia Scale among older adults in the Lao People's Democratic Republic.

METHODS

A community-based cross-sectional investigation was conducted in rural and urban settings in six districts of three provinces in the country from January to July 2020. In total, 2206 individuals aged 60-98 years (1110 men and 1096 women) were interviewed in person using a pretested Lao version of the Revised Hasegawa Dementia Scale and the WHO STEPwise approach to noncommunicable disease (NCD) risk factor surveillance (the STEPS survey tool). The adjusted odds ratios (AORs) and 95% confidence intervals (95% CIs) were estimated using a logistic model.

RESULTS

The study found that 49.3% (1088/2206) of respondents (39.7% [441/1110] of men and 59.0% [647/1096] of women) had scores associated with some level of cognitive impairment. In addition to age, the following factors were significantly associated with cognitive impairment: having no formal education (AOR = 9.5; 95% CI: 5.4 to 16.8, relative to those with a university education), living in the northern region of the country (AOR = 1.4; 95% CI: 1.1 to 1.9, relative to living in the central region), living in a rural area (AOR = 1.5; 95% CI: 1.2 to 1.8), needing assistance with self-care (AOR = 1.8; 95% CI: 1.2 to 2.7) and being underweight (AOR = 1.5; 95% CI: 1.1 to 2.2). Factors associated with no cognitive impairment among older adults include engaging in moderate-intensity physical activity lasting for 10 minutes and up to 1 hour (AOR = 0.6; 95% CI: 0.5 to 0.8) and for > 1 hour (AOR = 0.6; 95% CI: 0.4 to 0.8).

CONCLUSIONS

Using the Lao version of the Revised Hasegawa Dementia Scale, this study found that more than half of adults aged ≥ 60 years had cognitive impairment, and this impairment was associated with several risk factors. The limitations of this study may include possible overdetection due to the cutoff point for the assessment of cognitive decline used in the Revised Hasegawa Dementia Scale, given that the participants were not familiar with the instrument. However, the study results can be used to help inform health policy in the Lao People's Democratic Republic regarding the urgent need for a routine data collection system and for providing an environment that addresses and reduces the identified risk factors for cognitive decline to mitigate their impact.

Objective and Subjective Hearing Difficulties Are Associated With Lower Inhibitory Control

OBJECTIVE

Evidence suggests that hearing loss increases the risk of cognitive impairment. However, the relationship between hearing loss and cognition can vary considerably across studies, which may be partially explained by demographic and health factors that are not systematically accounted for in statistical models.

DESIGN

Middle-aged to older adult participants (N = 149) completed a web-based assessment that included speech-in-noise (SiN) and self-report measures of hearing, as well as auditory and visual cognitive interference (Stroop) tasks. Correlations between hearing and cognitive interference measures were performed with and without controlling for age, sex, education, depression, anxiety, and self-rated health.

RESULTS

The risk of having objective SiN difficulties differed between males and females. All demographic and health variables, except education, influenced the likelihood of reporting hearing difficulties. Small but significant relationships between objective and reported hearing difficulties and the measures of cognitive interference were observed when analyses were controlled for demographic and health factors. Furthermore, when stratifying analyses for males and females, different relationships between hearing and cognitive interference measures were found. Self-reported difficulty with spatial hearing and objective SiN performance were better predictors of inhibitory control in females, whereas self-reported difficulty with speech was a better predictor of inhibitory control in males. This suggests that inhibitory control is associated with different listening abilities in males and females.

CONCLUSIONS

The results highlight the importance of controlling for participant characteristics when assessing the relationship between hearing and cognitive interference, which may also be the case for other cognitive functions, but this requires further investigations. Furthermore, this study is the first to show that the relationship between hearing and cognitive interference can be captured using web-based tasks that are simple to implement and administer at home without any assistance, paving the way for future online screening tests assessing the effects of hearing loss on cognition.

Gender-specific prevalence and risk factors of mild cognitive impairment among older adults in Chongming, Shanghai, China

Objective

This study explores the gender differences in the prevalence of mild cognitive impairment (MCI) and the correlation between multiple influencing factors.

Materials and methods

The sample was comprised of 1325 relatively healthy participants aged ≥ 60 years in a Shanghai community-dwelling (557 males and 768 females). Cognitive function was assessed by Mini-Mental State Examination (MMSE). The Instrumental Activities of Daily Living (IADL) scale was used to assess the activities of daily living.

Results

The overall prevalence of MCI was 15.2%, with 10.2% in men and 18.9% in women. In older male subjects, those with higher the Geriatric Depression Scale (GDS) scores [odds ratio (OR) = 1.07, 95% confidence interval (CI) = 1.01–1.14] and hypertension (OR = 2.33, 95% CI = 1.15–4.73) had a higher risk of MCI. female subjects who were illiterate (OR = 2.95, 95% CI = 1.82–4.78), had a farming background (OR = 1.69, 95% CI = 1.05–2.72), and a history of stroke (OR = 1.96, 95% CI = 1.07–3.59) had a higher risk of MCI, but this was not true for males. However, Male subjects who never smoked were less likely to have MCI (OR = 0.22, 95% CI = 0.09–0.54). Additionally, the prevalence of MCI was lower in older women with high grip strength (OR = 0.96, 95% CI = 0.92–0.99) and hyperlipidemia (OR = 0.45, 95% CI = 0.22–0.96).

Conclusion

The prevalence of MCI was higher in the population of elderly women compared to men. Moreover, it was found that members with MCI tended to having higher GDS scores, smoking, and hypertension; whereas a history of farming, illiteracy, stroke, grip strength, and hyperlipidemia were correlated with MCI in women.

Association between functional disability and long-term trajectories of depressive symptoms: Evidence from the China Health and Retirement Longitudinal Study

BACKGROUND

Prior research has suggested that functional disability was associated with increased risk of incident depressive symptoms in the elderly. However, little is known about the potential role of functional disability on the long-term trajectories of depressive symptoms among middle-aged and older Chinese adults.

METHODS

Data were drawn from the China Health and Retirement Longitudinal Study. A total of 8415 participants with up to four measurements of depressive symptoms assessed by the Center for Epidemiologic Studies Depression Scale (CESD) were included. Functional disability was evaluated by activities of daily living (ADLs) and instrumental ADLs (IADLs) at baseline. We identified the trajectories of depressive symptoms over 7-year follow-up using group-based trajectory modelling, and examined the association between functional disability and depressive symptom trajectories using multinomial logistic regression.

RESULTS

We identified four trajectories of depressive symptoms throughout the follow-up, characterized by maintaining a low CES-D score (low symptoms); maintaining a moderate CES-D score (moderate symptoms); increasing progressively and reaching a high CES-D score at the end of follow-up (increasing symptom); and increasing quickly and maintaining a high CES-D score (high symptoms). We found that participants with severe functional disability were at increased likelihood of being in the moderate (odds ratio [OR] = 2.27, 95% confidence interval [CI] 1.68-3.07), increasing (OR = 2.31, 95% CI 1.49-3.59), and high (OR = 4.74, 95% CI 3.07-7.31) depressive symptom trajectories.

LIMITATIONS

Depressive symptoms and functional disability were evaluated based on self-reported scales.

CONCLUSIONS

Our findings suggest that functional disability was associated with unfavorable depressive symptom trajectories among middle-aged and older Chinese adults.

Social Isolation and Incident Dementia in the Oldest-Old-A Competing Risk Analysis

Purpose

Social isolation is considered a risk factor for dementia. However, less is known about social isolation and dementia with respect to competing risk of death, particularly in the oldest-old, who are at highest risk for social isolation, dementia and mortality. Therefore, we aimed to examine these associations in a sample of oldest-old individuals.

Methods

Analyses were based on follow-up (FU) 5-9 of the longitudinal German study AgeCoDe/AgeQualiDe. Social isolation was assessed using the short form of the Lubben Social Network Scale (LSNS-6), with a score ≤ 12 indicating social isolation. Structured interviews were used to identify dementia cases. Competing risk analysis based on the Fine-Gray model was conducted to test the association between social isolation and incident dementia.

Results

Excluding participants with prevalent dementia, n = 1,161 individuals were included. Their mean age was 86.6 (SD = 3.1) years and 67.0% were female. The prevalence of social isolation was 34.7% at FU 5, 9.7% developed dementia and 36.0% died during a mean FU time of 4.3 (SD = 0.4) years. Adjusting for covariates and cumulative mortality risk, social isolation was not significantly associated with incident dementia; neither in the total sample (sHR: 1.07, 95%CI 0.65-1.76, p = 0.80), nor if stratified by sex (men: sHR: 0.71, 95%CI 0.28-1.83, p = 0.48; women: sHR: 1.39, 95%CI 0.77-2.51, p = 0.27).

Conclusion

In contrast to the findings of previous studies, we did not find an association between social isolation and incident dementia in the oldest-old. However, our analysis took into account the competing risk of death and the FU period was rather short. Future studies, especially with longer FU periods and more comprehensive assessment of qualitative social network characteristics (e.g., loneliness and satisfaction with social relationships) may be useful for clarification.

Occasions for laughter and dementia risk: Findings from a six-year cohort study

AIM

Currently, there is little evidence on the relationship between laughter and the risk of dementia, and since laughter is mainly a social behavior, we aimed to examine the association between various occasions for laughter and the risk of dementia in Japanese older adults.

METHODS

We draw upon 6-year follow-up data from the Japan Gerontological Evaluation Study, including 12 165 independent older adults aged 65 years or over. Occasions for laughter were assessed using a questionnaire, while dementia was diagnosed using the standardized dementia scale of the long-term care insurance system in Japan. Cox proportional hazards models were estimated, yielding hazard ratios and 95% confidence intervals (CIs).

RESULTS

The multivariable hazard ratio of dementia incidence for all participants in the groups for high versus low variety of occasions for laughter was 0.84 (95% CI: 0.72-0.98, P for trend <0.001). A greater variety of occasions for laughter was associated with a lower risk of dementia 0.78 (95% CI: 0.63-0.96, P for trend <0.001) among women, but was less pronounced for men, with significant associations only for the medium group. Laughing during conversations with friends, communicating with children or grandchildren, and listening to the radio were primarily associated with decreased risk.

CONCLUSION

A greater variety of laughter occasions in individual and social settings was associated with a reduced risk of dementia. Geriatr Gerontol Int 2022; 22: 392-398.

Relationship between physical activity and cognitive functioning among older Indian adults

In a culturally different and low-resource setting, where lifestyle habits, including dietary pattern and physical activities differ from those in high-income countries, the association between physical activity and cognition is expected to differ. We aimed to investigate the association between physical activity and cognitive functioning after controlling for potential confounders among older adults in India. Furthermore, gender differences in this relationship were analyzed. Using a national-level data from the Longitudinal Ageing Study in India (2017-2018), this paper employed propensity score matching (PSM) approach to examine the association between physical activities and cognitive functioning among Indian older adults. Cognitive impairment was measured through five broad domains (memory, orientation, arithmetic function, executive function, and object naming). We limit our sample to older adults aged 60 + years, and our final dataset contains 31,464 participants (men = 16,366, and women = 15,098). The results indicated that older adults who engaged in frequent physical activity have greater cognitive functioning than older adults without physical activity after adjusting for various individual, health, lifestyle, and household factors. This association holds true for both older men and older women. The results from the PSM revealed that the cognitive function score was increased by 0.98 and 1.32 points for the frequently physically active older men and women population, respectively. The results demonstrate the possible beneficial effects of frequent physical activity on cognitive functioning among older adults. Thus, regular physical activity can be considered as an effective lifestyle factor to promote healthy cognitive aging.

Gender Modifies the Association of Cognition With Age-Related Hearing Impairment in the Health and Retirement Study

Introduction: Despite growing recognition of hearing loss as a risk factor for late life cognitive disorders, sex and gender analysis of this association has been limited. Elucidating this is one means to advocate for holistic medicine by considering the psychosocial attributes of people. With a composite Gender Score (GS), we aimed to assess this among aging participants (50+) from the 2016 Health and Retirement Study (HRS) cohort.

Methods: The GS was derived from gender-related variables in HRS by factor analyses and logistic regression, ranging from 0 (toward masculinity) to 100 (toward femininity). GS tertiles were also used to indicate three gender types (GS tertile 1: lower GS indicates masculinity; GS tertile 2: middle GS indicates androgyny; GS tertile 3: higher GS indicates femininity). Univariate followed by multiple logistic regressions were used to estimate the Odds Ratio (OR) and 95% confidence intervals (CI) of cognitive impairment (assessed by adapted Telephone Interview for Cognitive Status) from hearing acuity, as well as to explore the interactions of sex and gender with hearing acuity. The risk of cognitive impairment among hearing-impaired participants was assessed using multivariable models including sex and gender as exposure variables.

Results: Five variables (taking risks, loneliness, housework, drinking, and depression) were retained to compute the GS for each participant. The distribution of GS between sexes partly overlapped. After adjusting for confounding factors, the OR for cognitive impairment associated with hearing impairment was significantly higher (OR = 1.65, 95% CI: 1.26, 2.15), and this association was not modified by female sex (OR = 0.77, 95% CI: 0.46, 1.27), but by androgynous gender (OR = 0.44, 95% CI: 0.24, 0.81). In the multivariable models for participants with hearing impairment, androgynous and feminine gender, as opposed to female sex, was associated with lower odds of cognitive impairment (OR of GS tertile 2 = 0.59, 95% CI: 0.41, 0.84; OR of GS tertile 3 = 0.60, 95% CI: 0.41, 0.87; OR of female sex = 0.78, 95% CI: 0.57, 1.08).

Conclusions: Hearing impairment was associated with cognitive impairment among older people, and this association may be attenuated by a more feminine GS.

Gender Differences in the Link Between Marital Status and the Risk of Cognitive Impairment: Results From the Korean Longitudinal Study of Aging

In the context of South Korea, characterized by increasing population aging and a changing family structure, this study examined differences in the risk of cognitive impairment by marital status and investigated whether this association differs by gender. The data were derived from the 2006-2018 Korean Longitudinal Study of Aging. The sample comprised 7,568 respondents aged 45 years or older, who contributed 30,414 person-year observations. Event history analysis was used to predict the odds of cognitive impairment by marital status and gender. Relative to their married counterparts, never-married and divorced people were the most disadvantaged in terms of cognitive health. In addition, the association between marital status and cognitive impairment was much stronger for men than for women. Further, gender-stratified analyses showed that, compared with married men, never-married men had a higher risk of cognitive impairment, but there were no significant effects of marital status for women.

Carvalho O, Barros H. Global Cognitive Impairment Prevalence and Incidence in Community Dwelling Older Adults-A Systematic Review

(1) Background: We proposed to review worldwide estimates of cognitive impairment prevalence and incidence in adults older than 50 years of age living in the community. (2) Methods: Systematic searches were performed in January 2019 using MEDLINE/PubMed. Articles were selected if they referred to cognitive impairment, prevalence, incidence, elders, and population or community-based studies. Analysis, aggregated by different methodologic features, was performed. (3) Results: Prevalence (80 studies) ranged between 5.1% and 41% with a median of 19.0% (25th percentile = 12.0%; 75th percentile = 24.90%). Incidence (11 studies) ranged from 22 to 76.8 per 1000 person-years with a median of 53.97 per 1000 person-years (25th percentile = 39.0; 75th percentile = 68.19). No statistically significant effects were found except for inclusion age. (4) Conclusion: We propose that the homogenization and clarification of the definition of what constitutes cognitive impairment are essential to refine the epidemiological understanding of this entity. The results of this review reinforce the importance of adherence to standardized cut-off scores for cognitive tests to promote study comparability.

Gender and Educational Differences in the Association between Lifestyle and Cognitive Decline over 10 Years: The Doetinchem Cohort Study

BACKGROUND

Several modifiable risk factors for cognitive decline have been identified, but whether differences by gender and educational level exist is unclear.

OBJECTIVE

The present study aims to clarify this by prospectively investigating the relationship between health and lifestyle factors and cognitive functioning in different subgroups defined by gender and educational level.

METHODS

2,347 cognitive healthy individuals (mean age = 54.8, SD = 6.8, range: 41-71; 51.8% female; 26.2% low education) from the Doetinchem Cohort Study were examined for cognitive function at baseline, and at 5- and 10-year follow-up. Health- and lifestyle factors were captured by a poly-environmental risk score labelled 'LIfestyle for BRAin Health' (LIBRA). This score consists of 12 modifiable risk and protective factors for cognitive decline and dementia, with higher scores indicating greater risk (range: -2.7 to +12.7). Heterogeneity in associations between LIBRA and decline in verbal memory, cognitive flexibility, and mental speed between males and females and individuals with different levels of education were assessed in linear mixed models.

RESULTS

Overall, higher LIBRA scores predicted faster decline in verbal memory, cognitive flexibility, and mental speed over 10 years. Higher LIBRA scores were further associated with increased risk for incident cognitive impairment (one-point increase in LIBRA: HR = 1.09, 1.04-1.14, p = 0.001). In general, these effects were similar across gender and educational level.

CONCLUSION

A composite risk score comprising unhealthy lifestyle and relatively poor health in midlife is significantly associated with a worse course of cognition 10 years later. These associations were for the most part unrelated to gender or educational differences.

Gender Differences in the Impact of Depression on Cognitive Decline Among Korean Older Adults

This study aimed to investigate whether (1) depression is associated with cognitive decline in Korean older adults and (2) the relationship between depression and cognitive function varies by gender. Using Korean Longitudinal Study of Aging data of 2006 to 2014, we studied 1787 adults aged 65 years or older who had normal cognitive function at baseline. This study examined the effects of depression on cognitive decline by using an interaction term of baseline depression and time, and compared relationships by gender. Among male participants, K-MMSE (Korean-Mini-Mental Status Examination) scores decreased with age, at an annual rate of approximately 0.465 points. Baseline depression was found to accelerate the decline in cognitive function, by approximately 0.184 points per year. Among female participants, K-MMSE scores decreased with age, at an annual rate of approximately 0.585 points. Baseline depression was not related to the decline in cognitive function. These results suggest the need for community-based programs to increase awareness of mental health problems need to be developed to encourage the use of health services to prevent or delay cognitive decline in older Korean males.

Cognitive impairment in a primary healthcare population: a cross-sectional study on the island of Crete, Greece

OBJECTIVES

Cognitive impairment is known to have a significant impact on the quality of life of individuals and their caregivers, yet it is often underdiagnosed. The objective of this study is to assess the extent of cognitive impairment among elders visiting primary healthcare (PHC) practice settings, to explore associated risk factors and discuss current care challenges for PHC providers.

DESIGN

A cross-sectional study was conducted between March 2013 and May 2014.

SETTING

Fourteen PHC units located in rural and urban areas of the Heraklion district in Crete, Greece.

PARTICIPANTS

Consecutive visitors aged at least 60 years attending selected PHC practices.

PRIMARY AND SECONDARY OUTCOME MEASURES

The Mini-Mental State Examination (MMSE) was used to indicate cognitive status. Associations of low MMSE scores (≤23/24, adjusted for education level) with 12 socio-demographic factors, comorbidities and lifestyle factors were assessed.

RESULTS

A total of 3140 PHC patients met inclusion criteria (43.2% male; mean age 73.7±7.8 years). The average MMSE score was 26.0±3.8; 26.7±3.5 in male and 25.4±3.9 in female participants (p<0.0001). Low MMSE scores were detected in 20.2% of participants; 25.9% for females vs 12.8% for males; p<0.0001. Female gender (adjusted OR (AOR)=2.72; 95% CI 2.31 to 3.47), age (AOR=1.11; 95% CI 1.10 to 1.13), having received only primary or no formal education (AOR=2.87; 95% CI 2.26 to 3.65), alcohol intake (AOR=1.19; 95% CI 1.03 to 1.37), reporting one or more sleep complaints (AOR 1.63; 95% CI 1.14 to 2.32), dyslipidaemia (AOR=0.80; 95% CI 0.65 to 0.98) and history of depression (AOR=1.90; 95% CI 1.43 to 2.52) were associated with low MMSE scores.

CONCLUSIONS

This study identified a relatively high prevalence of low MMSE scores among persons attending PHC practices in a southern European community setting and associations with several known risk factors.

Cognitive Function Is a Prognostic Factor for Mortality of Nursing Home Residents during a 3-Year Observational Period

Introduction

Assessing cognitive function could help to provide appropriate care for nursing home residents. The aim of the study was to identify the factors affecting cognitive function in nursing home residents in Poland and assess how it influenced the mortality rate during a 3-year observational period.

Methods

This study included 202 elderly individuals from a nursing home in 2015. The investigation included examination of cognitive function using the MMSE and bioelectrical impedance analysis. Collected data included sex, age, blood pressure (BP), heart rate, number of comorbidities, years spent in the nursing home, educational level, and cigarette-smoking.

Results

The mean MMSE score was 21.36 ± 6.35, which was negatively correlated with age and diastolic BP (p = 0.001 and p = 0.024, respectively) and positively correlated with body mass, BMI, fat-free mass, fat, muscle mass, and education level (p = 0.004, p = 0.004, p = 002, p = 0.049, p = 0.005, and p ˂ 0.001, respectively). Patients who died during the observational period had lower MMSE scores than those who survived (23.34 ± 5.68 vs. 20.16 ± 6.45; p < 0.001). Smokers had better MMSE results than nonsmokers (23.34 ± 5.98 vs. 20.08 ± 4.94; p < 0.001).

Discussion

Polish nursing home residents had mild cognitive impairment depending on their age, sex, educational level, and nutritional status. Lower MMSE score was a prognostic factor for mortality in the 3-year observational period.

The association between health-related factors, physical and mental diseases, social activities, and cognitive function in elderly Koreans: a population-based cross-sectional study

AIM

The purpose of this study was to verify the association of cognitive function with health-related variables, diseases, and social activities.

METHODS

Data from the 2016 Korean Longitudinal Study of Aging were analyzed. The participants of that study were 5678 adults aged 60 years or older living in 17 major Korean regions nationwide.

RESULTS

Hierarchical multiple regression analyses indicated that gender, age, education, marital status, depressive symptoms, body mass index, regular exercise, activities of daily living, instrumental activities of daily living, hand grip strength, and social activities were all significantly associated with cognitive function in elderly Koreans. However, socioeconomic status, diabetes, smoking, alcohol consumption, attendance at school reunions, volunteer work, and participation in political or civic organizations had no impact on cognitive function. First, the results indicated that men had better cognitive function than women; likewise, married individuals and those with a higher level of education also had better cognitive function. As age increased, cognitive function declined. Second, higher body mass index was related to poorer cognitive function, whereas regular exercise was positively associated with better cognitive function. In addition, higher activities of daily living and instrumental activities of daily living scores were associated with poorer cognitive function. Third, depressive symptoms were negatively associated with cognitive function. Finally, religious activities, social activities, and participation in leisure activities, cultural events, and sports were associated with better cognitive functioning. The possibility of reverse association exists between some of the variables (e.g. religious activity and cognitive function), and it is necessary to verify this possibility through a longitudinal study. The biggest limitation is that this is a cross-sectional study, which made it unfeasible to investigate the causal pathways.

CONCLUSIONS

This study suggests that regularly exercising and attending social activities each help to improve cognitive function in the elderly.

Risk and Protective Factors for the Onset of Cognitive Impairment in Korea: A 10-Year Longitudinal Panel Study

OBJECTIVE

This study aimed to examine the associations between multiple modifiable risk/protective factors and the onset of cognitive impairment, using nationally representative panel data spanning 10 years.

METHODS

A total of 7,568 respondents who were cognitively normal at baseline were included and followed up for 10 years using data from the 2006-2016 Korean Longitudinal Study of Ageing. The data were converted into 28,113 person-year observations, and a life table approach and a series of event history models were used to estimate the transition rates to cognitive impairment over time and to examine the influence of time-varying factors on the onset of cognitive impairment. Cognitive impairment was measured using the Korean version of the Mini-Mental State Exam.

RESULTS

About half of the respondents without cognitive impairment at baseline had experienced cognitive impairment by the end of the last interview, and women were more likely than men to experience cognitive impairment during the observation period. Vascular risk factors, hearing loss, socioeconomic status, regular exercise, participation in social activities, and frequent contact with close friends were significantly associated with the onset of cognitive impairment.

CONCLUSION

This investigation of modifiable factors for cognitive impairment using population-based data may lead to the identification of preventive strategies that people could integrate into their lifestyles.

Productive Activities and Risk of Cognitive Impairment and Depression: Does the Association Vary by Gender?

We examine how labor together with social participation protects against cognitive impairment and depression, with a focus on gender differences. Data are drawn from four waves of the Korean Longitudinal Study of Aging (2006-2012). Both paid work and unpaid work are considered labor participation. Social participation includes the frequency of participation in formal social institutions, religious groups, grandparenting, and interactions with family and friends. Using growth curve models, we find that social and labor participation are independently associated with outcomes and effects vary by gender. Religious group activity was beneficial only for women, whereas inability to work was detrimental for men only. Informal social gatherings and labor participation, paid or unpaid, were beneficial for both genders. Findings on gender differences highlight how social identities can shape social roles and confine activity space, and productive engagement, affecting outcomes for mental health in later life.

Cognitive impairment and its risk factors among Myanmar elderly using the Revised Hasegawa's Dementia Scale: A cross-sectional study in Nay Pyi Taw, Myanmar

Background

Globally, elderly population with impaired cognitive function, such as dementia, has been accelerating, and Myanmar is no exception. However, cognitive function among elderly in Myanmar has rarely been assessed. This study aimed to identify the rate of cognitive impairment and its risk factors among the elderly in Myanmar.

Methods

This cross-sectional study was conducted at rural health centers in Nay Pyi Taw Union Territory, Myanmar, from December 2018 to January 2019. In total, 757 elderly individuals aged 60 years or over (males: 246 [32.5%], females: 511 [67.5%]) were interviewed using a face-to-face method with a pre-tested questionnaire. Descriptive statistics and multivariable logistic regression analyses were performed.

Results

The rate of impaired cognitive function among participants was 29.9% (males: 23.6%; females: 32.9%). The following participants were more likely to present cognitive impairment: those aged 70–79 years (adjusted odds ratio [AOR] = 1.8; 95% confidence interval [CI]: 1.19–2.70) and 80 years or older (AOR = 3.9; 95% CI: 2.25–6.76); those who were illiterate (AOR = 9.1; 95% CI: 3.82–21.51); and those dependent on family members (AOR = 1.6; 95% CI: 1.04–2.44). The elderly livening with their families and those who reported having good health (AOR = 0.7; 95% CI: 0.44–0.99) were less likely to have cognitive impairment.

Conclusion

Using the HDS-R Myanmar version, this study reported that there out of five elderly participants had cognitive impairment, and its risk factors, altering policy makers that Myanmar needs to prepare for adequate healthcare services and social support for elderly with cognitive impairment. Future research should be performed not only to detect general cognitive impairment but also to differentiate specific cognitive domains impairments among Myanmar elderly. Longitudinal studies are needed to observe the causal and protective factors associated with cognitive impairments in Myanmar.

Orexin and Alzheimer's Disease: A New Perspective

Orexin's role in human cognition has recently been emphasized and emerging evidences indicate its close relationship with Alzheimer's disease (AD). This review aimed to demonstrate recent research on the relationship between orexin and AD. Orexin's role in stress regulation and memory is discussed, with significant findings related to sexual disparities in stress response, with potential clinical implications pertaining to AD pathology. There are controversies regarding the orexin levels in AD patients, but the role of orexin in the trajectory of AD is still emphasized in recent literatures. Orexin is also accentuated in the context of tau pathology, and orexin as a potential therapeutic target for AD is frequently discussed. Future directions with regard to the relationship between orexin and AD are suggested: 1) consideration for AD trajectory in the measurement of orexin levels, 2) the need for objective measure such as polysomnography and actigraphy, 3) the need for close observation of cognitive profiles of orexin-deficient narcolepsy patients, 4) the need for validation studies by neuroimaging 5) the need for taking account sexual disparities in orexinergic activiation, and 6) consideration for orexin's role as a stress regulator. The aforementioned new perspectives could help unravel the relationship between orexin and AD.

Behavioral and Psychological Symptoms that Predict Cognitive Decline or Impairment in Cognitively Normal Middle-Aged or Older Adults: a Meta-Analysis

Epidemiological studies have revealed that behavioral and psychological (or non-cognitive) symptoms are risk factors for cognitive decline in older adults. This study aimed to systematically review the literature and determine which behavioral and psychological symptoms are most predictive of future cognitive decline among individuals with no pre-existing cognitive impairments. The selected studies included middle-aged or older adults without cognitive impairments. The predictors were assessed using behavioral and psychological questionnaires, or diagnostic interviews, to identify non-cognitive symptoms or psychiatric clinical conditions. The follow-up period was at least one year, and the design of the selected studies was either retrospective or prospective. This study compared individuals with and without non-cognitive manifestations and resulted in one of three outcomes: (a) a score change on a cognitive measure, (b) a diagnosis of mild cognitive impairment, or (c) a diagnosis of Alzheimer's disease or dementia. Four online databases were searched for eligible studies from the database inception to January 17, 2017: MEDLINE (PubMed), Embase (OVID), PsycINFO, and Web of Science. Pooled effect sizes were estimated using a random-effect model. Higgins I², the Q statistic, and tau-squared were used to quantify the observed heterogeneity between the studies. Results indicate that depression and sleep duration (long and short) were the most consistent associations between behavioral or psychological symptoms and cognitive decline. This meta-analysis supports the need to assess behavioral and psychological symptoms in cognitively intact older adults to identify those who are at risk for cognitive decline.

Gender Differences in the Association Between Hearing Loss and Cognitive Function

OBJECTIVE

This study aimed to determine the association between hearing loss and cognitive function by gender in a nationally representative sample of older adults.

METHODS

We used data from the National Health and Nutrition Examination Survey (2010-2011) for 655 participants aged 60 to 69 years. The cognitive functioning component consisted of the Consortium to Establish a Registry for Alzheimer's disease, the Animal Fluency Test, and the Digit Symbol Substitution Test. We created a composite z score to represent global cognitive function. Regression models were used to examine the association between hearing loss and cognitive function.

RESULTS

Moderate/severe hearing loss was significantly associated with lower composite z score in males (β = -28.67, 95% confidence interval [95% CI] = -57.13 to -0.20) but not in females (β = -8.82, 95% CI = -36.61 to 18.96).

CONCLUSION

There were gender differences in the association between hearing loss and cognitive function. Future studies need to investigate these gender-specific associations.

Prediction of future cognitive impairment among the community elderly: A machine-learning based approach

The early detection of cognitive impairment is a key issue among the elderly. Although neuroimaging, genetic, and cerebrospinal measurements show promising results, high costs and invasiveness hinder their widespread use. Predicting cognitive impairment using easy-to-collect variables by non-invasive methods for community-dwelling elderly is useful prior to conducting such a comprehensive evaluation. This study aimed to develop a machine learning-based predictive model for future cognitive impairment. A total of 3424 community elderly without cognitive impairment were included from the nationwide dataset. The gradient boosting machine (GBM) was exploited to predict cognitive impairment after 2 years. The GBM performance was good (sensitivity = 0.967; specificity = 0.825; and AUC = 0.921). This study demonstrated that a machine learning-based predictive model might be used to screen future cognitive impairment using variables, which are commonly collected in community health care institutions. With efforts of enhancing the predictive performance, such a machine learning-based approach can further contribute to the improvement of the cognitive function in community elderly.

Gender difference in cognitive health among older Indian adults: A cross-sectional multilevel analysis

This study assesses the gender gap in cognitive health among older adults in India and examines the extent to which individual, household and state level characteristics contribute to the male-female difference in cognitive health. The study is based on 6548 women and men who participated in the WHO Study on Global AGEing and Adult Health conducted in six states in India during 2007-08. Multilevel ordinary least square regression was used to examine the gender difference in cognitive health, adjusting for individual, household, health behavior and state-level variables. A composite cognitive score (CCS) was calculated by combining z-scores of five individual cognitive tests. Results suggest that CCS is worse among women than among men after adjusting for individual and state level factors. The largest reduction in the gender gap in CCS was observed when adjusting for education, followed by other individual factors such as marital status, individual height, caste, religion, tobacco consumption and chronic health status. Although state level urbanization and female workforce participation rate were significantly associated with CCS, these characteristics did not contribute to the reduction of gender difference in CCS. This study extends the current knowledge of women's disadvantage in cognitive health, demonstrating that individual level characteristics remain key determinants of gender difference in cognition among older adults in India. Importantly, this relationship holds in the context of very large cross-state variations in cognitive health and its determinants.

The risk of cognitive impairment associated with hearing function in older adults: a pooled analysis of data from eleven studies

Impaired hearing and cognition are disabling conditions among older adults. Research has presented inconsistent conclusions regarding hearing impairment posing a risk for cognitive impairment. We aimed to assess this from published evidence via searching PubMed and Embase, from the inception of the databases indexed to December 2, 2016. For those high-quality studies retrieved, relative risk (RR) and 95% confidence intervals (CIs) were combined to estimate the risk of cognitive impairment. Eleven cohort studies were included in the present study. Pooled results found that elderly people with disabled peripheral and central hearing function had a higher risk of cognitive impairment (for moderate/severe peripheral hearing impairment: RR = 1.29, 95% CI: 1.04-1.59 during a follow-up ≤6 years. RR = 1.57, 95% CI: 1.13-2.20 during a follow-up >6 years; for severe central hearing impairment, RR = 3.21, 95% CI: 1.19-8.69) compared to those with normal hearing function. We also recorded a dose-response trend for cognitive impairment as hearing thresholds rose. No evident bias from potential confounding factors was found with one exception: the length for clinical follow-up. Although results are preliminary because qualifying studies were few, statistical findings were consistent with older people identified as having greater levels of hearing loss, having a corresponding higher risk of cognitive impairment.