Association of loneliness and social isolation with all-cause mortality among older Mexican adults in the Mexican health and aging study: a retrospective observational study.

BACKGROUND: Plenty of evidence shows how social isolation and loneliness are associated with increased risk for numerous diseases and mortality. But findings about their interactive or combined effects on health outcomes and mortality remains inconclusive. OBJECTIVE: Analyze the longitudinal association of loneliness, social isolation and their interactions, with the all-cause mortality among older adults in Mexico. METHODS: A retrospective observational study was conducted. Mexican adults older than 50 years were included. Data from the Mexican Health and Aging Study (MHAS) in the 2015 and 2018 waves were used. The subjects were classified according to their level of loneliness and the presence of social isolation. Multivariate logistic regression analyzes were performed to determine the degree of association between loneliness and social isolation with all-cause mortality at a 3-year follow-up. RESULTS: From the total sample of 11,713 adults aged 50 years or over, 707 (6%) did not survive, 42% presented loneliness, and 53% were classified as socially isolated. After multivariate adjustment only social isolation (OR = 1.30, 95%CI:1.03-1.64) was associated with all-cause mortality, loneliness (Mild: OR = 0.83, 95%CI:0.59-1.16; Severe: OR = 1.03, 95%CI:0.71-1.64), and the interaction between loneliness and social isolation were not associated with all-cause mortality. CONCLUSION: Social isolation, but not loneliness or their interaction, was associated with all-cause mortality in Mexican adults older than 50 years. This finding may help direct possible future interventions that help improve mental health in older adults from a highly collectivistic country.

Predictors of Successful Memory Aging in Older Mexican Adults.

Background: Research suggests a significant association between increasing age and memory impairments. Nevertheless, for some individuals, memory performance stays within or above the normative values of younger subjects. This is known as successful memory aging and is associated with specific neurophysiological features and psychological and lifestyle-related variables. To date, little is known about the association between successful memory aging and intrinsic capacity (IC) defined as "the composite of all the physical and mental (including psychosocial) capacities that an individual can draw on at any point in time" and resilience. Hence, the aim of this study was to determine if longitudinal associations between IC and successful memory aging and resilience exist and to find differences in cognitive performance between Mexican older adults with successful memory aging, older adults with average memory, and older adults with memory impairment. Methods: Longitudinal data from 590 individuals from the third wave (2012) and the Mex-Cog subsample (2016) of the Mexican Health and Aging Study was analysed. Subjects were classified into 3 groups: (1) older adults with successful memory aging (SUMA), (2) older adults with average memory (AVMA), and (3) older adults with memory impairment (IMA). Cognitive domains of orientation, language, attention, constructional praxis, and executive function were evaluated. IC and resilience were measured using items from the MHAS battery. Analysis of variance and multinomial logistic regressions were used to find differences in IC and resilience across the memory aging groups. Results: ANOVAs showed significant differences across the three cognitive performance groups in all cognitive domains. Multinomial logistic regression analyses revealed that respondents with higher scores in the psychological and cognitive domains of IC at baseline were more likely to have successful memory aging in the subsequent wave of the study. More resilient subjects in 2012 were not more likely to become a SUMA in 2016. However, this could be a result of the way resilience was measured. Conclusion: Our main findings suggest that intrinsic capacity could be used as a predictor of successful memory aging specifically in the psychological and the cognitive domains. More longitudinal studies are needed to further examine these associations.

Syntactic Gender Agreement Processing on Direct-Object Clitics by Spanish-Speaking Children with Developmental Language Disorder: Evidence from ERP.

Children with developmental language disorder (DLD) have a psycholinguistic profile evincing multiple syntactic processing impairments. Spanish-speaking children with DLD struggle with gender agreement on clitics; however, the existing evidence comes from offline, elicitation tasks. In the current study, we sought to determine whether converging evidence of this deficit can be found. In particular, we use the real-time processing technique of event-related brain potentials (ERP) with direct-object clitic pronouns in Spanish-speaking children with DLD. Our participants include 15 six-year-old Mexican Spanish-speaking children with DLD and 19 typically developing, age-matched (TD) children. Auditory sentences that matched or did not match the gender features of antecedents represented in pictures were employed as stimuli in a visual-auditory gender agreement task. Gender-agreement violations were associated with an enhanced anterior negativity between 250 and 500 ms post-target onset in the TD children group. In contrast, children with DLD showed no such effect. This absence of the left anterior negativity (LAN) effect suggests weaker lexical representation of morphosyntactic gender features and/or non-adult-like morphosyntactic gender feature checking for the DLD children. We discuss the relevance of these findings for theoretical accounts of DLD. Our findings may contribute to a better understanding of syntactic agreement processing and language disorders.

Longitudinal relationship of diabetes and depressive symptoms in older adults from Mexico: a secondary data analysis.

INTRODUCTION: Several studies have argued a causal relationship between diabetes and depression, while others have highlighted that their association is a result of common risk factors. Because Mexico is a country with a high prevalence of diabetes, and diabetes and depression are a frequent comorbidity, we chose this country to investigate the longitudinal relationship of these two conditions, focusing on the influence of demographic, health, and socioeconomic factors which could act as common risk factors for both conditions. RESEARCH DESIGN AND METHODS: Using the harmonized Mexican Health and Aging Study, a nationally representative sample of adults older than 50 with a response rate of 93%, we analyzed the longitudinal relationship of diabetes and depressive symptoms using 'between-within' random-effects models, focusing on the effect of demographic, socioeconomic and health factors. RESULTS: While older adults with diabetes reported a higher prevalence of depressive symptoms in the four waves of the study, there was no causal longitudinal association between them once controlling for demographic, socioeconomic and health factors (between-effect OR=0.88, 95% CI 0.77 to 1.01; within-effect OR=0.87, 95% CI 0.69 to 1.11). CONCLUSIONS: There is no causal longitudinal association between diabetes and depression; the higher prevalence of depression among older adults with diabetes seems a result of socioeconomic and health factors that are not exclusive to respondents with diabetes but are more frequent in this group. Our results highlight the importance of prevention and control of chronic conditions as well as the role of socioeconomic inequalities in mental health.

Cognitive Reserve and Executive Functions in Adults with Type 2 Diabetes.

BACKGROUND: Adults with type two diabetes mellitus (DM2) show cognitive deficits within the executive function domain. The detrimental effects of DM2 over executive function (EF) performance may be mediated by factors such as cognitive reserve (CR). CR mediates cognitive performance by delaying the appearance of clinical symptoms from subjacent brain pathology or attenuating the severity of such symptoms. Our main goal was to study the effects of CR on executive functions of adults with DM2. METHODS: Data from a total of 1,034 adults were included (362 women, 672 men). Subjects were categorized into four groups: subjects with DM2 and high CR (n = 235), control subjects with high CR (n = 265), subjects with DM2 and low CR (n = 298), and control subjects with low CR (n = 236). CR was quantified through 3 proxies: education, occupational complexity, and leisure activities. Executive functions were evaluated through visual scanning, verbal fluency, and backwards counting tasks. First, a series of four one-way ANOVAs was performed where group was included as a between-subject factor and executive function as a dependent variable. Second, a hierarchical multiple regression analysis was conducted to assess the weight of each CR proxy on EF performance. RESULTS: CR level significantly affected all executive function scores independently of the diabetes status. Hierarchical regression analyses indicated that years of education accounted for most of the variance in the model for executive function performance. In this study, we found that there is a significant effect of CR on executive function performance of DM2 subjects and education is the most important CR proxy.