Social Isolation and Loneliness in a Population Study of Cognitive Impairment: The MYHAT Study

In this study, we examined associations of social isolation and loneliness with cognitive impairment among older adults from a Rust Belt region in Southwest Pennsylvania. We used data from the population-based Monongahela-Youghiogheny Healthy Aging Team (MYHAT) study. We found that (a) 11 items combined into two reliable composites of social isolation and loneliness; (b) unique to this study, providing unpaid help to others was an indicator of reduced social isolation; (c) social isolation and loneliness were positively associated with cognitive impairment; and (d) these associations were appreciably attenuated by general health and physical functional status and depressive symptoms, respectively. We concluded that social isolation and loneliness are differentially associated with older adults' cognitive health, and that their effects might operate through separate pathways. Approaches to address social isolation and loneliness should consider the community context and its implications for older adults' cognitive health.

Reading the Mind in the Eyes: A Population-Based Study of Social Cognition in Older Adults

BACKGROUND

Social cognition indicates the cognitive processes involved in perceiving, interpreting, and processing social information. Although it is one of the six core DSM-5 cognitive domains for diagnosing neurocognitive disorders, it is not routinely assessed in older adults. The Reading the Mind in the Eyes Test assesses Theory of Mind, the social cognition mechanism which forms the root of empathy.

OBJECTIVES

To describe the distribution of, and factors associated with, scores on a 10-item version of Reading the Mind in the Eyes Test (RMET-10) in older adults.

DESIGN

Population-based cross-sectional study.

SETTING

Small-town communities in Pennsylvania.

PARTICIPANTS

Adults aged 66-105 years (N = 902, mean age = 76.6).

MEASUREMENTS

The assessment included RMET-10, demographics, cognitive screening, literacy, depression symptoms, anxiety symptoms, cognitive composites derived from a neuropsychological test battery, Social Norms Questionnaire, and Clinical Dementia Rating (CDR).

RESULTS

RMET-10 score was normally distributed in our overall study sample. Normative RMET-10 scores among those rated as CDR = 0 were calculated by age, sex, and education. RMET-10 score was significantly higher with younger age, higher education, white race, higher cognitive screening scores, literacy, social norms scores, higher scores in all five domains in cognitive composites, and lower CDR. RMET-10 score was also significantly higher with fewer depression and anxiety symptoms after adjusting for demographics.

CONCLUSIONS

The RMET is a potentially useful measure of social cognition for use in the research assessment of older adults. With appropriate calibration it should also have utility in the clinical setting.

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.

Social isolation, loneliness, and cognitive impairment in late life: The MYHAT study

Background

Social isolation and loneliness have detrimental effects on the health of older adults. Being socially isolated and lonely are likely both predictors and consequences of cognitive impairment with aging. However, isolation and loneliness may be differentially associated with cognitive impairment and may operate through both shared and unique pathways. The present study aimed to examine the association of social isolation and loneliness with concurrent cognitive impairment, and to explore potential mechanisms of the association.

Methods

Participants (n =1,982; Mage = 77.65 years, 1,210 (61.1%) female, 1,877 (94.7%) white, 815 (41.12% > high school education) were from a population‐based study of mild cognitive impairment and dementia. Three composite measures derived from factor analysis, representing social network structure, social connectedness, and loneliness were examined in relation to clinical dementia rating (CDR normal = 0 vs. CDR impaired >= 0.5) at baseline, adjusted for demographic characteristics. The indirect effects of the composite measures were also estimated conditioned on general health and function, lifestyle factors, vascular health, depressive symptoms, and sleep.

Results

Of the participants, 569 (28.71%) were cognitively impaired at baseline. Social connectedness (OR 1.48, 95% CI=1.33‐1.64) and loneliness (OR 1.38, 95% CI=1.24‐1.54), but not social network structure, were significantly associated with greater likelihood of being cognitively impaired after adjustment for demographics. These effects remained significant after separate adjustments for general health and function, lifestyle factors, vascular health, depressive symptoms, sleep, and other composites. The effect of social connectedness was appreciably attenuated by general health status and function (OR 1.37, 95% CI=1.22‐1.54), while loneliness was appreciably attenuated by depressive symptoms (OR 1.26, 95% CI=1.12‐1.42).

Conclusions

Older adults with lower levels of social connectedness and higher perception of loneliness are more likely to be cognitively impaired, which were partially explained by health and function and depressive symptoms, respectively. Addressing these factors may reduce risk for cognitive impairment, or conversely, reduce risk for disconnectedness and loneliness among those with cognitive impairment. These results have implications for the impact that limited social contact and feelings of loneliness during the COVID‐19 pandemic may have on older adults with or at risk for cognitive impairment.

A cross-national study of depression in preclinical dementia: A COSMIC collaboration study

INTRODUCTION

Depression commonly accompanies Alzheimer's disease, but the nature of this association remains uncertain.

METHODS

Longitudinal data from the COSMIC consortium were harmonized for eight population-based cohorts from four continents. Incident dementia was diagnosed in 646 participants, with a median follow-up time of 5.6 years to diagnosis. The association between years to dementia diagnosis and successive depressive states was assessed using a mixed effect logistic regression model. A generic inverse variance method was used to group study results, construct forest plots, and generate heterogeneity statistics.

RESULTS

A common trajectory was observed showing an increase in the incidence of depression as the time to dementia diagnosis decreased despite cross-national variability in depression rates.

DISCUSSION

The results support the hypothesis that depression occurring in the preclinical phases of dementia is more likely to be attributable to dementia-related brain changes than environment or reverse causality.

Education and the moderating roles of age, sex, ethnicity and apolipoprotein epsilon 4 on the risk of cognitive impairment

BACKGROUND

We examined how the relationship between education and latelife cognitive impairment (defined as a Mini Mental State Examination score below 24) is influenced by age, sex, ethnicity, and Apolipoprotein E epsilon 4 (APOE*4).

METHODS

Participants were 30,785 dementia-free individuals aged 55-103 years, from 18 longitudinal cohort studies, with an average follow-up ranging between 2 and 10 years. Pooled hazard ratios were obtained from multilevel parametric survival analyses predicting cognitive impairment (CI) from education and its interactions with baseline age, sex, APOE*4 and ethnicity. In separate models, education was treated as continuous (years) and categorical, with participants assigned to one of four education completion levels: Incomplete Elementary; Elementary; Middle; and High School.

RESULTS

Compared to Elementary, Middle (HR = 0.645, P = 0.004) and High School (HR = 0.472, P < 0.001) education were related to reduced CI risk. The decreased risk of CI associated with Middle education weakened with older baseline age (HR = 1.029, P = 0.056) and was stronger in women than men (HR = 1.309, P = 0.001). The association between High School and lowered CI risk, however, was not moderated by sex or baseline age, but was stronger in Asians than Whites (HR = 1.047, P = 0.044), and significant among Asian (HR = 0.34, P < 0.001) and Black (HR = 0.382, P = 0.016), but not White, APOE*4 carriers.

CONCLUSION

High School completion may reduce risk of CI associated with advancing age and APOE*4. The observed ethnoregional differences in this effect are potentially due to variations in social, economic, and political outcomes associated with educational attainment, in combination with neurobiological and genetic differences, and warrant further study.

Determinants of cognitive performance and decline in 20 diverse ethno-regional groups: A COSMIC collaboration cohort study

BACKGROUND

With no effective treatments for cognitive decline or dementia, improving the evidence base for modifiable risk factors is a research priority. This study investigated associations between risk factors and late-life cognitive decline on a global scale, including comparisons between ethno-regional groups.

METHODS AND FINDINGS

We harmonized longitudinal data from 20 population-based cohorts from 15 countries over 5 continents, including 48,522 individuals (58.4% women) aged 54-105 (mean = 72.7) years and without dementia at baseline. Studies had 2-15 years of follow-up. The risk factors investigated were age, sex, education, alcohol consumption, anxiety, apolipoprotein E ε4 allele (APOE*4) status, atrial fibrillation, blood pressure and pulse pressure, body mass index, cardiovascular disease, depression, diabetes, self-rated health, high cholesterol, hypertension, peripheral vascular disease, physical activity, smoking, and history of stroke. Associations with risk factors were determined for a global cognitive composite outcome (memory, language, processing speed, and executive functioning tests) and Mini-Mental State Examination score. Individual participant data meta-analyses of multivariable linear mixed model results pooled across cohorts revealed that for at least 1 cognitive outcome, age (B = -0.1, SE = 0.01), APOE*4 carriage (B = -0.31, SE = 0.11), depression (B = -0.11, SE = 0.06), diabetes (B = -0.23, SE = 0.10), current smoking (B = -0.20, SE = 0.08), and history of stroke (B = -0.22, SE = 0.09) were independently associated with poorer cognitive performance (p < 0.05 for all), and higher levels of education (B = 0.12, SE = 0.02) and vigorous physical activity (B = 0.17, SE = 0.06) were associated with better performance (p < 0.01 for both). Age (B = -0.07, SE = 0.01), APOE*4 carriage (B = -0.41, SE = 0.18), and diabetes (B = -0.18, SE = 0.10) were independently associated with faster cognitive decline (p < 0.05 for all). Different effects between Asian people and white people included stronger associations for Asian people between ever smoking and poorer cognition (group by risk factor interaction: B = -0.24, SE = 0.12), and between diabetes and cognitive decline (B = -0.66, SE = 0.27; p < 0.05 for both). Limitations of our study include a loss or distortion of risk factor data with harmonization, and not investigating factors at midlife.

CONCLUSIONS

These results suggest that education, smoking, physical activity, diabetes, and stroke are all modifiable factors associated with cognitive decline. If these factors are determined to be causal, controlling them could minimize worldwide levels of cognitive decline. However, any global prevention strategy may need to consider ethno-regional differences.

Development of a risk stratification system to guide treatment for female germ cell tumors

OBJECTIVE

Due to their rarity, little is known about prognostic factors in female germ cell tumors (GCTs) or outcomes following systemic therapy. Management is largely based on studies of male GCT and epithelial ovarian cancer.

METHODS

Chart review was performed for all females with GCT seen at Memorial Sloan Kettering Cancer Center (MSKCC) from 1990 to 2012. Patients receiving chemotherapy were stratified using a modification of the male IGCCCG risk system, and the classifier was correlated with outcome.

RESULTS

Of 93 patients, 92 (99%) underwent primary surgery and 85 (92%) received chemotherapy. Modified IGCCCG classification was significantly associated with progression-free survival (PFS) and overall survival (OS), both when applied preoperatively and pre-chemotherapy (p<0.001 for all four analyses). Progression after initial chemotherapy (n=29) was detected by imaging in 14 (48%) patients, by serum tumor markers in 6 (21%) patients, and by multiple methods in the rest. Seven (29%) of 24 patients treated with salvage chemotherapy achieved long-term PFS, including 4/6 who received high-dose chemotherapy (HDCT) as initial salvage versus 3/16 treated with other initial salvage regimens. The estimated 3-year OS rate was 84% (95% CI, 76-92%), with a trend favoring dysgerminoma over non-dysgerminoma histologies (p=0.12).

CONCLUSIONS

Modified IGCCCG classification was prognostic for female GCT patients in this cohort and identified a poor-risk group who may benefit from more intensive first-line chemotherapy. Both imaging and tumor marker evaluation were important in identifying relapses after first-line chemotherapy. The majority of long-term remissions with salvage therapy were achieved with initial salvage HDCT.