The Paradoxical Effect of Living Alone on Cognitive Reserve and Mild Cognitive Impairment among Women Aged 60+ in Mexico City

Healthy aging meta-analyses and scoping review of risk factors across Latin America reveal large heterogeneity and weak predictive models

Models of healthy aging are typically based on the United States and Europe and may not apply to diverse and heterogeneous populations. In this study, our objectives were to conduct a meta-analysis to assess risk factors of cognition and functional ability across aging populations in Latin America and a scoping review focusing on methodological procedures. Our study design included randomized controlled trials and cohort, case-control and cross-sectional studies using multiple databases, including MEDLINE, the Virtual Health Library and Web of Science. From an initial pool of 455 studies, our meta-analysis included 38 final studies (28 assessing cognition and 10 assessing functional ability, n = 146,000 participants). Our results revealed significant but heterogeneous effects for cognition (odds ratio (OR) = 1.20, P = 0.03, confidence interval (CI) = (1.0127, 1.42); heterogeneity: I2 = 92.1%, CI = (89.8%, 94%)) and functional ability (OR = 1.20, P = 0.01, CI = (1.04, 1.39); I2 = 93.1%, CI = (89.3%, 95.5%)). Specific risk factors had limited effects, especially on functional ability, with moderate impacts for demographics and mental health and marginal effects for health status and social determinants of health. Methodological issues, such as outliers, inter-country differences and publication bias, influenced the results. Overall, we highlight the specific profile of risk factors associated with healthy aging in Latin America. The heterogeneity in results and methodological approaches in studying healthy aging call for greater harmonization and further regional research to understand healthy aging in Latin America.

Mild cognitive impairment in pemphigus

BACKGROUND

Pemphigus is a group of autoimmune blistering disorders that have been associated with dementia in previous studies. Mild cognitive impairment (MCI) can be the first stage of progression into dementia. The objective of the present study was to evaluate the frequency of MCI in pemphigus patients compared to a control group.

METHODS

This case-control study included 80 patients with pemphigus referred to the dermatology clinics of Shohadaye Tajrish and Loghman Hakim hospitals, Tehran, Iran, in 2021. A group of 80 individuals without pemphigus who visited the same clinics for cosmetic consultation or interventions were regarded as controls. Age, sex, marital status, and education were recorded for all participants. Disease duration, medications, and severity were noted for pemphigus patients. The Persian version of the Montreal Cognitive Assessment (MoCA) test was used to assess cognitive function.

RESULTS

MCI was significantly more frequent in pemphigus patients than in controls (55% vs. 37.5%, P = 0.026). Furthermore, the total MoCA score was significantly lower in pemphigus patients compared to controls (23.98 ± 3.77 vs. 25.21 ± 3.45, P = 0.032); however, among MoCA's different domains, only the executive functions score was significantly lower in pemphigus patients (P = 0.010). After adjustment, multivariable logistic regression analysis revealed that every 1-year higher education in patients decreased the odds of MCI by 52% (adjusted odds ratio = 0.483, 95% confidence interval 0.326; 0.715, P < 0.001).

CONCLUSIONS

The frequency of MCI was found to be significantly higher, and overall scores of the MoCA test, as well as its executive function domain, were significantly lower among pemphigus patients in this study compared to the control group. Additionally, a higher level of education was associated with decreased odds of MCI in pemphigus patients. Identifying pemphigus patients with MCI through the use of the MoCA test can facilitate early intervention, enabling them to seek help and support.

Health-related heterogeneity in brain aging and associations with longitudinal change in cognitive function

Introduction

Neuroimaging-based 'brain age' can identify individuals with 'advanced' or 'resilient' brain aging. Brain-predicted age difference (brain-PAD) is predictive of cognitive and physical health outcomes. However, it is unknown how individual health and lifestyle factors may modify the relationship between brain-PAD and future cognitive or functional performance. We aimed to identify health-related subgroups of older individuals with resilient or advanced brain-PAD, and determine if membership in these subgroups is differentially associated with changes in cognition and frailty over three to five years.

Methods

Brain-PAD was predicted from T1-weighted images acquired from 326 community-dwelling older adults (73.8 ± 3.6 years, 42.3% female), recruited from the larger ASPREE (ASPirin in Reducing Events in the Elderly) trial. Participants were grouped as having resilient (n=159) or advanced (n=167) brain-PAD, and latent class analysis (LCA) was performed using a set of cognitive, lifestyle, and health measures. We examined associations of class membership with longitudinal change in cognitive function and frailty deficit accumulation index (FI) using linear mixed models adjusted for age, sex and education.

Results

Subgroups of resilient and advanced brain aging were comparable in all characteristics before LCA. Two typically similar latent classes were identified for both subgroups of brain agers: class 1 were characterized by low prevalence of obesity and better physical health and class 2 by poor cardiometabolic, physical and cognitive health. Among resilient brain agers, class 1 was associated with a decrease in cognition, and class 2 with an increase over 5 years, though was a small effect that was equivalent to a 0.04 standard deviation difference per year. No significant class distinctions were evident with FI. For advanced brain agers, there was no evidence of an association between class membership and changes in cognition or FI.

Conclusion

These results demonstrate that the relationship between brain age and cognitive trajectories may be influenced by other health-related factors. In particular, people with age-resilient brains had different trajectories of cognitive change depending on their cognitive and physical health status at baseline. Future predictive models of aging outcomes will likely be aided by considering the mediating or synergistic influence of multiple lifestyle and health indices alongside brain age.

The effects of loneliness, social isolation, and associated gender differences on the risk of developing cognitive impairment for Chinese oldest old

OBJECTIVES

To investigate whether loneliness and social isolation could independently predict subsequent risk of cognitive impairment in Chinese oldest old, and to examine possible gender differences.

METHODS

The sample included 2,732 older adults aged 80 years and above with intact cognitive function from the Chinese Longitudinal Healthy Longevity Survey 2002-2018 waves, with an average follow-up of 4.24 years. Loneliness was measured by a single-item question about how often the participant felt lonely. Social isolation was defined by marital status, frequent visits by family members, and social activity engagement. Cognitive impairment was defined based on Mini-Mental State Examination scores.

RESULTS

Cox regression showed that social isolation independently predicted a higher risk of developing cognitive impairment at follow-up (HR = 1.14, 95% CI [1.03, 1.27], p = 0.014). Importantly, although there was no main effect of loneliness, a significant interaction between gender and loneliness (p = 0.013) suggested that increased loneliness was associated with a higher risk of developing cognitive impairment for men but not for women.

CONCLUSION

To prevent cognitive impairment and promote healthy longevity, socially isolated adults in their oldest old age should receive more attention, and men who often feel lonely should be offered with more emotional support.