Clinical, physical and lifestyle variables and relationship with cognition and mood in aging: a cross-sectional analysis of distinct educational groups

Association between Depressive Mood, Antidepressant Therapy and Neuropsychological Performances: Results from a Cross-Sectional Study on Elderly Patients

BACKGROUND

Currently, the global demographic landscape is undergoing a transformative shift towards an increasingly aging population. This leads to an increase in chronic pathologies, including depression and cognitive impairment. This study aimed to evaluate the association between depressive mood, whether in treatment or not, and cognitive capacities, assessed using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS).

METHODS

This study included 259 subjects, aged 65 years or older, evaluated at the Geriatric Outpatient Service of the University Hospital of Monserrato, Cagliari, between July 2018 and May 2022, who experienced subjective depressive mood and/or cognitive deficits.

RESULTS

Only 25.1% of the sample showed no cognitive impairment on the RBANS. Education was a significant regressor of the RBANS Total Scale scores (p < 0.0001) and was negatively associated with mood deflection (r = -0.15, p = 0.0161). Subjects with depressive mood had more impaired attention and visuospatial/constructional abilities compared to untreated euthymic patients. Post-hoc analysis, conducted with the Conover test, showed that untreated euthymic patients (GDS-15 ≤ 5, group 2) had a higher score on the RBANS total scale than patients with mood deflection (GDS-15 > 5, group 1), and treated euthymic patients (GDS-15 ≤ 5, group 3). Finally, different logistic regression analyses revealed a significant negative coefficient for GDS as a regressor of the RBANS total scale (coefficient: -0.04, p = 0.0089), visuospatial/constructional abilities (coefficient: -0.03, p = 0.0009), language (coefficient: -0.05, p = 0.0140), and attention (coefficient: -0.05, p < 0.0001).

CONCLUSIONS

Our analysis demonstrated that "naturally" euthymic people show better cognitive performances than people with depressive mood and subjects with acceptable mood due to antidepressants. Furthermore, the gender-based difference observed in the language domain suggests the potential utility of incorporating an alternative category for male patients in the Semantic Fluency test.

The association between persistent cognitive difficulties and depression and functional outcomes in people with major depressive disorder

BACKGROUND

Cognitive symptoms are common during and following episodes of depression. Little is known about the persistence of self-reported and performance-based cognition with depression and functional outcomes.

METHODS

This is a secondary analysis of a prospective naturalistic observational clinical cohort study of individuals with recurrent major depressive disorder (MDD; N = 623). Participants completed app-based self-reported and performance-based cognitive function assessments alongside validated measures of depression, functional disability, and self-esteem every 3 months. Participants were followed-up for a maximum of 2-years. Multilevel hierarchically nested modelling was employed to explore between- and within-participant variation over time to identify whether persistent cognitive difficulties are related to levels of depression and functional impairment during follow-up.

RESULTS

508 individuals (81.5%) provided data (mean age: 46.6, s.d.: 15.6; 76.2% female). Increasing persistence of self-reported cognitive difficulty was associated with higher levels of depression and functional impairment throughout the follow-up. In comparison to low persistence of objective cognitive difficulty (<25% of timepoints), those with high persistence (>75% of timepoints) reported significantly higher levels of depression (B = 5.17, s.e. = 2.21, p = 0.019) and functional impairment (B = 4.82, s.e. = 1.79, p = 0.002) over time. Examination of the individual cognitive modules shows that persistently impaired executive function is associated with worse functioning, and poor processing speed is particularly important for worsened depressive symptoms.

CONCLUSIONS

We replicated previous findings of greater persistence of cognitive difficulty with increasing severity of depression and further demonstrate that these cognitive difficulties are associated with pervasive functional disability. Difficulties with cognition may be an indicator and target for further treatment input.

Poor Cognitive Agility Conservation in Obese Aging People

Life expectancy has been boosted in recent decades at expenses of increasing the age-associated diseases. Dementia, for its incidence, stands out among the pathologies associated with aging. The exacerbated cognitive deterioration disables people from carrying out their daily lives autonomously and this incidence increases exponentially after 65 years of age. The etiology of dementia is a miscellaneous combination of risk factors that restrain the quality of life of our elderly. In this sense, it has been established that some metabolic pathologies such as obesity and diabetes act as a risk factor for dementia development. In contrast, a high educational level, as well as moderate physical activity, have been shown to be protective factors against cognitive impairment and the development of dementia. In the present study, we have evaluated the metabolic composition of a population between 60-90 years old, mentally healthy and with high academic degrees. After assessing agility in mental state, we have established relationships between their cognitive abilities and their body composition. Our data support that excess body fat is associated with poorer maintenance of cognition, while higher percentages of muscle mass are associated with the best results in the cognitive tests.

The aging mind: A complex challenge for research and practice

Cognitive decline as part of mental ageing is typically assessed with standardized tests; below-average performance in such tests is used as an indicator for pathological cognitive aging. In addition, morphological and functional changes in the brain are used as parameters for age-related pathological decline in cognitive abilities. However, there is no simple link between the trajectories of changes in cognition and morphological or functional changes in the brain. Furthermore, below-average test performance does not necessarily mean a significant impairment in everyday activities. It therefore appears crucial to record individual everyday tasks and their cognitive (and other) requirements in functional terms. This would also allow reliable assessment of the ecological validity of existing and insufficient cognitive skills. Understanding and dealing with the phenomena and consequences of mental aging does of course not only depend on cognition. Motivation and emotions as well personal meaning of life and life satisfaction play an equally important role. This means, however, that cognition represents only one, albeit important, aspect of mental aging. Furthermore, creating and development of proper assessment tools for functional cognition is important. In this contribution we would like to discuss some aspects that we consider relevant for a holistic view of the aging mind and promote a strengthening of a multidisciplinary approach with close cooperation between all basic and applied sciences involved in aging research, a quick translation of the research results into practice, and a close cooperation between all disciplines and professions who advise and support older people.

The longitudinal impact of the COVID-19 pandemic on health behaviors, psychosocial factors, and cognitive functioning in older adults

Background: Older adults are at a greater risk for contracting and experiencing severe illness from COVID-19 and may be further affected by pandemic-related precautions (e.g., social distancing and isolation in quarantine). However, the longitudinal impact of the COVID-19 pandemic on older adults is unclear. The current study examines changes in health behaviors, psychosocial factors, and cognitive functioning in a large sample of older adults using a pre-pandemic baseline and longitudinal follow-up throughout 9 months of the COVID-19 pandemic. Methods: One hundred and eighty-nine older adults (ages 65-89) were recruited from a multisite clinical trial to complete additional virtual assessments during the COVID-19 pandemic. Mixed effects models evaluated changes in health behaviors, psychosocial factors, and cognitive functioning during the pandemic compared to a pre-pandemic baseline and over the course of the pandemic (i.e., comparing the first and last COVID-19 timepoints). Results: Compared to their pre-pandemic baseline, during the pandemic, older adults reported worsened sleep quality, perceived physical health and functioning, mental health, slight increases in depression and apathy symptoms, reduced social engagement/perceived social support, but demonstrated better performance on objective cognitive tasks of attention and working memory. Throughout the course of the pandemic, these older adults reported continued worsening of perceived physical health and function, fewer depression symptoms, and they demonstrated improved cognitive performance. It is important to note that changes on self-report mood measures and cognitive performance were relatively small regarding clinical significance. Education largely served as a protective factor, such that greater years of education was generally associated with better outcomes across domains. Conclusions: The present study provides insights into the longitudinal impact of the COVID-19 pandemic on health behaviors, psychosocial factors, and cognitive functioning in a population disproportionately affected by the virus. Replicating this study design in a demographically representative older adult sample is warranted to further inform intervention strategies targeting older adults negatively impacted by the COVID-19 pandemic.

Optimized Multiscale Entropy Model Based on Resting-State fMRI for Appraising Cognitive Performance in Healthy Elderly

Many studies have indicated that an entropy model can capture the dynamic characteristics of resting-state functional magnetic resonance imaging (rfMRI) signals. However, there are problems of subjectivity and lack of uniform standards in the selection of model parameters relying on experience when using the entropy model to analyze rfMRI. To address this issue, an optimized multiscale entropy (MSE) model was proposed to confirm the parameters objectively. All healthy elderly volunteers were divided into two groups, namely, excellent and poor, by the scores estimated through traditional scale tests before the rfMRI scan. The parameters of the MSE model were optimized with the help of sensitivity parameters such as receiver operating characteristic (ROC) and area under the ROC curve (AUC) in a comparison study between the two groups. The brain regions with significant differences in entropy values were considered biomarkers. Their entropy values were regarded as feature vectors to use as input for the probabilistic neural network in the classification of cognitive scores. Classification accuracy of 80.05% was obtained using machine learning. These results show that the optimized MSE model can accurately select the brain regions sensitive to cognitive performance and objectively select fixed parameters for MSE. This work was expected to provide the basis for entropy to test the cognitive scores of the healthy elderly.

Magnetic resonance elastography of the ageing brain in normal and demented populations: A systematic review

The aim of this systematic review was to evaluate the ability of magnetic resonance elastography (MRE) to identify significant changes in brain mechanical properties during normal and pathological aging. PubMed, Web of Science and Scopus were searched for human studies using MRE to assess brain mechanical properties in cognitively healthy individuals, individuals at risk of dementia or patients diagnosed with dementia. Study characteristics, sample demographics, clinical characterization and main MRE outcomes were summarized in a table. A total of 19 studies (nine aging, 10 dementia), comprising 700 participants, were included. The main findings were decreased cerebral stiffness along aging, with rates of annual change ranging from −0.008 to −0.025 kPa per year. Also, there were regional differences in the age effect on brain stiffness. Concerning demented patients, differential patterns of stiffness were found for distinct dementia subtypes. Alzheimer's disease and frontotemporal dementia exhibited decreased brain stiffness in comparison to cognitively healthy controls and significant declines were found in regions known to be affected by the disease. In normal pressure hydrocephalus, the results were not consistent across studies, and in dementia with Lewy bodies no significant differences in brain stiffness were found. In conclusion, aging is characterized by the softening of brain tissue and this event is even more pronounced in pathological aging, such as dementia. MRE technique could be applied as a sensible diagnostic tool to identify deviations from normal aging and develop new brain biomarkers of cognitive decline/dementia that would help promote healthier cognitive aging.

A novel method for estimating connectivity-based parcellation of the human brain from diffusion MRI: Application to an aging cohort

Connectivity‐based parcellation (CBP) methods are used to define homogenous and biologically meaningful parcels or nodes—the foundations of brain network fingerprinting—by grouping voxels with similar patterns of brain connectivity. However, we still lack a gold standard method and the use of CBPs to study the aging brain remains scarce. Our study proposes a novel CBP method from diffusion MRI data and shows its potential to produce a more accurate characterization of the longitudinal alterations in brain network topology occurring in aging. For this, we constructed whole‐brain connectivity maps from diffusion MRI data of two datasets: an aging cohort evaluated at two timepoints (mean interval time: 52.8 ± 7.24 months) and a normative adult cohort—MGH‐HCP. State‐of‐the‐art clustering techniques were used to identify the best performing technique. Furthermore, we developed a new metric (connectivity homogeneity fingerprint [CHF]) to evaluate the success of the final CBP in improving regional/global structural connectivity homogeneity. Our results show that our method successfully generates highly homogeneous parcels, as described by the significantly larger CHF score of the resulting parcellation, when compared to the original. Additionally, we demonstrated that the developed parcellation provides a robust anatomical framework to assess longitudinal changes in the aging brain. Our results reveal that aging is characterized by a reorganization of the brain's structural network involving the decrease of intra‐hemispheric, increase of inter‐hemispheric connectivity, and topological rearrangement. Overall, this study proposes a new methodology to perform accurate and robust evaluations of CBP of the human brain.

Evaluation of the genetic risk for COVID-19 outcomes in COPD and differences among worldwide populations

Background

Populations seem to respond differently to the global pandemic of severe acute respiratory syndrome coronavirus 2. Recent studies show individual variability in both susceptibility and clinical response to COVID-19 infection. People with chronic obstructive pulmonary disease (COPD) constitute one of COVID-19 risk groups, being already associated with a poor prognosis upon infection. This study aims contributing to unveil the underlying reasons for such prognosis in people with COPD and the variability in the response observed across worldwide populations, by looking at the genetic background as a possible answer to COVID-19 infection response heterogeneity.

Methods

SNPs already associated with susceptibility to COVID-19 infection (rs286914 and rs12329760) and severe COVID-19 with respiratory failure (rs657152 and rs11385942) were assessed and their allelic frequencies used to calculate the probability of having multiple risk alleles. This was performed on a Portuguese case-control COPD cohort, previously clinically characterized and genotyped from saliva samples, and also on worldwide populations (European, Spanish, Italian, African, American and Asian), using publicly available frequencies data. A polygenic risk analysis was also conducted on the Portuguese COPD cohort for the two mentioned phenotypes, and also for hospitalization and survival to COVID-19 infection.

Findings

No differences in genetic risk for COVID-19 susceptibility, hospitalization, severity or survival were found between people with COPD and the control group (all p-values > 0.01), either considering risk alleles individually, allelic combinations or polygenic risk scores. All populations, even those with European ancestry (Portuguese, Spanish and Italian), showed significant differences from the European population in genetic risk for both COVID-19 susceptibility and severity (all p-values < 0.0001).

Conclusion

Our results indicate a low genetic contribution for COVID-19 infection predisposition or worse outcomes observed in people with COPD. Also, our study unveiled a high genetic heterogeneity across major world populations for the same alleles, even within European sub-populations, demonstrating the need to build a higher resolution European genetic map, so that differences in the distribution of relevant alleles can be easily accessed and used to better manage diseases, ultimately, safeguarding populations with higher genetic predisposition to such diseases.

The Association of Metabolic Dysfunction and Mood Across Lifespan Interacts With the Default Mode Network Functional Connectivity

Background: Numerous studies suggest a relationship between depression and metabolic syndrome, which is likely influenced by age. Interestingly, functional imaging analysis has shown an association between functional connectivity in the default mode network (DMN-FC) and components of metabolic syndrome, which is explored in this study.

Methods: From a larger longitudinal cohort study on healthy aging, 943 individuals were extensively characterized for mood and cognition. Among these, 120 individuals who were selected for displaying extreme cognitive performance within the normal range (good and poor performers) were further studied. Here, in a cross-sectional design, using confirmatory factor analysis (CFA), the association between metabolic dysfunction and depressive mood as a function of age and its relationship with DMN-FC was studied.

Results: Metabolic dysfunction was modeled as a second-order latent variable using CFA. First-order latent variables were obesity, glucose dysmetabolism, lipids imbalance, and blood pressure. Using multiple linear regression models, this study observed that metabolic dysfunction, glucose dysmetabolism, and lipids imbalance were linearly associated with depressive mood, and the association with obesity was U-shaped. The association of metabolic dysfunction, obesity, and glucose dysmetabolism with depressive mood is positive for the younger individuals in our sample and vanishes with aging. The FC of the right superior temporal gyrus with the DMN correlated with both obesity and depressive mood. In participants with higher obesity scores, FC increased with higher GDS scores, while in those with lower GDS scores, FC decreased. Age and blood pressure were associated with a more complex pattern of association between FC of the right supramarginal gyrus and GDS score.

Conclusion: The association of metabolic dysfunction with depressive mood is influenced by age and relates with differential patterns of DMN-FC. The combination of the effects of age, mood, and metabolic dysfunction is likely to explain the heterogeneity of DMN-FC, which deserves further investigation with larger and longitudinal studies.

Educational level as a protective factor against the influence of depressive symptoms on cognition in older adults: implications for functional independence during a 10-year follow-up

OBJECTIVES

To examine whether the educational level moderates the relationship between baseline depressive symptoms and cognitive functioning at 5- and 10-year follow-ups in older adults, considering the association between cognitive functioning and difficulty with activities of daily living (ADL).

DESIGN

Using a prospective design, a path analysis was performed.

SETTING

In-home, face-to-face interviews and self-administered questionnaires, within the National Social Life, Health, and Aging Project.

PARTICIPANTS

In total, 1,461 participants (mean age = 66.62) were followed up from Wave 1 (baseline) to Wave 2 (at 5 years) and Wave 3 (at 10 years).

MEASUREMENTS

Depressive symptoms were assessed at baseline. Cognitive functioning and difficulty with ADL were assessed at baseline and at 5 and 10 years.

RESULTS

Educational level moderates the relationship between depressive symptoms and cognitive functioning at 5 years (β = 0.07, SE = 0.03, p = 0.04, Cohen's f2 = 0.02), being depressive symptoms related to poor cognitive functioning only at low educational levels. Cognitive functioning predicts difficulty with ADL at 5 and 10 years (β = -0.08, SE = 0.03, p = 0.008, Cohen's f2 = 0.01; β = -0.09, SE = 0.03, p = 0.006, Cohen's f2 = 0.02). The proposed model yielded excellent fit (CFI = 1.00, RMSEA = 0.0001, 90% CI 0.0001-0.03, SRMR = 0.004, and χ2(8) = 7.16, p = 0.52).

CONCLUSIONS

Cognitive reserve may act as a protective factor against the effect of depressive symptoms on cognition in older adults, which, in turn, is relevant to their functional independence.

Reorganization of brain structural networks in aging: A longitudinal study

Normal aging is characterized by structural and functional changes in the brain contributing to cognitive decline. Structural connectivity (SC) describes the anatomical backbone linking distinct functional subunits of the brain and disruption of this communication is thought to be one of the potential contributors for the age-related deterioration observed in cognition. Several studies already explored brain network's reorganization during aging, but most focused on average connectivity of the whole-brain or in specific networks, such as the resting-state networks. Here, we aimed to characterize longitudinal changes of white matter (WM) structural brain networks, through the identification of sub-networks with significantly altered connectivity along time. Then, we tested associations between longitudinal changes in network connectivity and cognition. We also assessed longitudinal changes in topological properties of the networks. For this, older adults were evaluated at two timepoints, with a mean interval time of 52.8 months (SD = 7.24). WM structural networks were derived from diffusion magnetic resonance imaging, and cognitive status from neurocognitive testing. Our results show age-related changes in brain SC, characterized by both decreases and increases in connectivity weight. Interestingly, decreases occur in intra-hemispheric connections formed mainly by association fibers, while increases occur mostly in inter-hemispheric connections and involve association, commissural, and projection fibers, supporting the last-in-first-out hypothesis. Regarding topology, two hubs were lost, alongside with a decrease in connector-hub inter-modular connectivity, reflecting reduced integration. Simultaneously, there was an increase in the number of provincial hubs, suggesting increased segregation. Overall, these results confirm that aging triggers a reorganization of the brain structural network.

Signatures of white-matter microstructure degradation during aging and its association with cognitive status

Previous studies have shown an association between cognitive decline and white matter integrity in aging. This led to the formulation of a "disconnection hypothesis" in the aging-brain, which states that the disruption in cortical network communication may explain the cognitive decline during aging. Although some longitudinal studies have already investigated the changes occurring in white matter microstructure, most focused on specific white matter tracts. Our study aims to characterize the longitudinal whole-brain signatures of white matter microstructural change during aging. Furthermore, we assessed the relationship between distinct longitudinal alterations in white matter integrity and cognition. White matter microstructural properties were estimated from diffusion magnetic resonance imaging, and cognitive status characterized from extensive neurocognitive testing. The same individuals were evaluated at two timepoints, with a mean interval time of 52.8 months (SD = 7.24) between first and last assessment. Our results show that age is associated with a decline in cognitive performance and a degradation in white matter integrity. Additionally, significant associations were found between diffusion measures and different cognitive dimensions (memory, executive function and general cognition). Overall, these results suggest that age-related cognitive decline is related to white matter alterations, and thus give support to the "disconnected hypothesis" of the aging brain.

Association of positive and negative life events with cognitive performance and psychological status in late life: A cross-sectional study in Northern Portugal

Objectives

Life events have important effects on psychological well-being. Yet, studies have mainly focused on exploring the impact of traumatic and negative experiences on health and well-being, with positive events receiving marginal attention. In this study, we investigated the association between negative and positive life events, cognitive performance and psychological status in older individuals.

Method

A cross-sectional approach with a sample of 97 community-dwelling adults, recruited from a network of 23 centres/institutions in Northern Portugal, and aged between 56 and 85 years, was conducted. All participants were evaluated through a battery of tests assessing for depressive mood, perceived stress, and cognitive functioning. Life events were measured using the Lifetime Experiences Scale (LIFES) which covers 75 life experiences organized in eight domains.

Results

A total of 95.9% of the participants reported more positive life events than negative throughout life. Participants reporting more positive experiences had lower scores in the depressive mood and perceived stress measures. At the domain-level of LIFES scale, more negative experiences in the Work and Health domains were associated with a depressed mood and more perceived stress. Significant positive associations were found between positive life experiences and most cognitive measures, after controlling for sex, education, age and depressive symptoms. Namely, more positive experiences at School, Leisure, and Living conditions were positively associated with better performance across cognitive tests.

Discussion

This study adds important evidence on the association between of life events, both negative and positive experiences, on cognition and psychological well-being, providing a more balanced view of the field.

Iron Status is Associated with Mood, Cognition, and Functional Ability in Older Adults: A Cross-Sectional Study

Several conditions are risk factors for iron deficiency (ID), some of which are highly prevalent in older individuals. Despite the amount of evidence pointing for a role of ID in cognition, mood and physical functional ability, the research addressing these associations in older individuals is still scarce. In the present study, 162 older community-dwelling individuals (29.53% classified as ID) were enrolled in a cross-sectional analysis and characterized regarding cognition, mood, functional ability, general nutritional intake and iron status. Assessment of iron status was performed using several blood biomarkers. Storage and erythropoiesis dimensions were positively associated with memory, along with an interaction (moderator effect) between iron storage and nutritional status. A more depressed mood was negatively associated with (iron) transport, transport saturation and erythropoiesis dimensions, and functional tiredness was positively associated with the erythropoiesis dimension. These observations indicate that lower iron status is associated with depressive mood, functional tiredness and poorer memory ability, with the latter moderated by nutritional status. These findings suggest that using iron as a continuous variable may be useful in finding associations with iron homeostasis, eventually missed when iron levels are considered within the usual classification groups.

Cognition Is Associated With Peripheral Immune Molecules in Healthy Older Adults: A Cross-Sectional Study

Background

Cognition in the elderly is heterogeneous. Senescence of the immune system is increasingly considered as a potential player in cognitive performance. We explored here the interplay between cognitive performance and peripheral immune molecules in healthy older individuals.

Methods

A cross-sectional study of clinically well characterized senior healthy individuals (120; 51-87 years old) previously clustered as "Good" and "Poor" performers based on established tests that evaluate memory and executive function. A plasma concentration of 30 immune molecules was assessed by multiplex analysis and correlated with parameters of cognitive performance.

Results

Participants with worse cognitive performance ("Poor") exhibited increased concentrations of IL-1β, IL-8, IL-13, and tumor necrosis factor (TNF) when compared to individuals with a better cognitive performance ("Good"). The cognitive dimensions memory and executive function, when considered separately, displayed a negative association with several immune molecules (IL-1β, IL-1RA, IL-6, IL-13, IP-10, and TNF with memory and only IL-1β with executive function), even controlling for age, sex, years of formal education, mood, and use of anti-inflammatory drugs. Regression analysis showed that several of these molecules (IL-1β, IL-6, IL-8, and IL-13) contribute to predicting whether an individual belongs to the "Good" or "Poor" cognitive performance group.

Conclusion

These results strengthen the hypothesis that increased concentrations of peripheral immune molecules, like IL-1β, are associated with worse cognitive performance in senior healthy individuals. It further highlights that some poorly studied immune molecules should be considered in the context of cognitive aging, such as IL-13, here revealed as a new player in such interaction.

Higher Adherence to the Mediterranean Diet Is Associated With Preserved White Matter Integrity and Altered Structural Connectivity

The Mediterranean diet (MedDiet) has been associated with cognitive performance. Yet, controlled trials have yielded contradictory results. To tackle this controversy, a comprehensive multimodal analysis of the association of the MedDiet with cognitive performance and brain structure in normative aging is still necessary. Here, community dwellers ≥50 years from a cohort study on normative aging (n = 76) underwent a (i) magnetic resonance imaging session with two acquisitions: structural and diffusion-weighted imaging (DWI); (ii) neuropsychological battery of tests focusing on memory and executive functioning; and (iii) dietary assessment through the Mediterranean Diet Assessment Screener (MEDAS, score range: 0-14, scores ≥10 indicate high adherence to the Mediterranean diet) 18 months prior to the brain imaging and neuropsychological assessment. We found that high adherence to the MedDiet (MEDAS ≥10) was associated with higher values of fractional anisotropy and lower diffusivity values in the brain white matter. Similarly, high adherence to the MedDiet was associated with higher structural connectivity between left hemisphere brain regions. Specifically, the amygdala, lingual, olfactory, middle occipital gyrus, and calcarine areas. No association was found between high adherence to the MedDiet and total brain volumes or hypointensities. Higher adherence to the MedDiet was positively associated with executive functioning scores. These results suggest that high adherence to the MedDiet positively associates with brain health, specifically with executive function scores and white matter integrity of bundles related to the processing and integration of taste, reward, and decision making. These findings seem to support the view that the MedDiet should be part of recommendations to promote a healthy brain.

Neurocognitive impairment in type 2 diabetes: evidence for shared genetic aetiology

AIMS/HYPOTHESIS

Type 2 diabetes is associated with cognitive impairments, but it is unclear whether common genetic factors influence both type 2 diabetes risk and cognition.

METHODS

Using data from 1892 Mexican-American individuals from extended pedigrees, including 402 with type 2 diabetes, we examined possible pleiotropy between type 2 diabetes and cognitive functioning, as measured by a comprehensive neuropsychological test battery.

RESULTS

Negative phenotypic correlations (ρp) were observed between type 2 diabetes and measures of attention (Continuous Performance Test [CPT d']: ρp = -0.143, p = 0.001), verbal memory (California Verbal Learning Test [CVLT] recall: ρp = -0.111, p = 0.004) and face memory (Penn Face Memory Test [PFMT]: ρp = -0.127, p = 0.002; PFMT Delayed: ρp = -0.148, p = 2 × 10-4), replicating findings of cognitive impairment in type 2 diabetes. Negative genetic correlations (ρg) were also observed between type 2 diabetes and measures of attention (CPT d': ρg = -0.401, p = 0.001), working memory (digit span backward test: ρg = -0.380, p = 0.005), and face memory (PFMT: ρg = -0.476, p = 2 × 10-4; PFMT Delayed: ρg = -0.376, p = 0.005), suggesting that the same genetic factors underlying risk for type 2 diabetes also influence poor cognitive performance in these domains. Performance in these domains was also associated with type 2 diabetes risk using an endophenotype ranking value approach. Specifically, on measures of attention (CPT d': β = -0.219, p = 0.005), working memory (digit span backward: β = -0.326, p = 0.035), and face memory (PFMT: β = -0.171, p = 0.023; PFMT Delayed: β = -0.215, p = 0.005), individuals with type 2 diabetes showed the lowest performance, while unaffected/unrelated individuals showed the highest performance, and those related to an individual with type 2 diabetes performed at an intermediate level.

CONCLUSIONS/INTERPRETATION

These findings suggest that cognitive impairment may be a useful endophenotype of type 2 diabetes and, therefore, help to elucidate the pathophysiological underpinnings of this chronic disease.

DATA AVAILABILITY

The data analysed in this study is available in dbGaP: www.ncbi.nlm.nih.gov/projects/gap/cgi-bin/study.cgi?study_id=phs001215.v2.p2.

Automatic speech analysis to early detect functional cognitive decline in elderly population

This study aimed at evaluating whether people with a normal cognitive function can be discriminated from subjects with a mild impairment of cognitive function based on a set of acoustic features derived from spontaneous speech. Voice recordings from 90 Italian subjects (age >65 years; group 1: 47 subjects with MMSE>26; group 2: 43 subjects with 20≤ MMSE ≤26) were collected. Voice samples were processed using a MATLAB-based custom software to derive a broad set of known acoustic features. Linear mixed model analyses were performed to select the features able to significantly distinguish between groups. The selected features (% of unvoiced segments, duration of unvoiced segments, % of voice breaks, speech rate, and duration of syllables), alone or in addition to age and years of education, were used to build a learning-based classifier. The leave-one-out cross validation was used for testing and the classifier accuracy was computed. When the voice features were used alone, an overall classification accuracy of 0.73 was achieved. When age and years of education were additionally used, the overall accuracy increased up to 0.80. These performances were lower than the accuracy of 0.86 found in a recent study. However, in that study the classification was based on several tasks, including more cognitive demanding tasks. Our results are encouraging because acoustic features, derived for the first time only from an ecologic continuous speech task, were able to discriminate people with a normal cognitive function from people with a mild cognitive decline. This study poses the basis for the development of a mobile application performing automatic voice analysis on-the-fly during phone calls, which might potentially support the detection of early signs of functional cognitive decline.

The moderator effect of age in the association between mood and adiposity in the elderly is specific for the subcutaneous adipose compartment: An MRI study

The positive association between obesity and depressive mood in young- and middle-age individuals is a phenomenon with major clinical implications in public health. Interestingly, the trend of this association in older individuals is not clear, given the conflicting results of multiple studies. Since aging is accompanied by changes in body fat distribution, we questioned whether age is a modulator of such association. This study explores the role of age in the association between mood and general (body mass index [BMI]) and abdominal adiposity (waist circumference [WC]) in older adults characterizing the different abdominal adipose tissue compartments (subcutaneous adipose tissue [SAT] and visceral adipose tissue [VAT]) with magnetic resonance imaging (MRI) techniques.

METHODS

One hundred twenty aged community-dwelling individuals (≥50 y of age) were assessed regarding depressive mood (Geriatric Depression Scale) and adiposity (BMI and WC). From these, 96 were assessed for SAT and VAT using MRI.

RESULTS

Using multiple linear regression models, depressive mood was positively associated with BMI, WC, and VAT. Age was a significant moderator of the association between depressive mood and BMI, WC, and SAT: positive in younger participants and null or negative in older participants. On the other hand, higher VAT was significantly associated with a more depressive mood, independently of age.

CONCLUSIONS

This study identifies age as a relevant moderator in the association between depressive mood and adiposity in the elderlies. Furthermore, the body fat compartment analysis revealed that the effect of age is specific for the SAT, suggesting its protective role in depressive mood.

25-OH Vitamin D Levels and Cognitive Performance: Longitudinal Assessment in a Healthy Aging Cohort

Background: Declining serum levels of 25-hydroxyvitamin D [25(OH)D, a biomarker of vitamin D status] with aging is a well-recognized phenomenon. However, scarce information is available on the relation between 25(OH)D levels and cognitive performance over time in older individuals. Our purpose was to evaluate, longitudinally, the association of 25(OH)D with cognitive function in a healthy older adults’ cohort.

Methods: Sixty-four individuals over 55 years-old with no cognitive impairment, clustered as healthy “Poor” and “Good” cognitive performers, were followed for an average of 18 months. Seasonal-adjusted 25(OH)D serum levels (measured by high-performance liquid chromatography-tandem mass spectrometry) were related, longitudinally, with cognitive (memory and general/executive) composite scores.

Results: Overall seasonal-adjusted median serum 25(OH)D level was of 47 nmol/l [interquartile range (IQR), 38–60 nmol/l]. A negative correlation between baseline 25(OH)D and the general/executive composite score was found in the “Poor” cognitive performers (r^s = −0.52, p = 0.006), an association lost after adjusting 25(OH)D levels for the season. No effect was found in both groups between seasonal-adjusted 25(OH)D levels and the variation of both memory and general/executive composites during follow-up when adjusted for age, gender and education level.

Conclusion: In this healthy older population with no cognitive impairment, lower serum levels of 25(OH)D were not longitudinally associated with poorer cognitive scores.

Asymmetrical subcortical plasticity entails cognitive progression in older individuals

Structural brain asymmetries have been associated with cognition. However, it is not known to what extent neuropsychological parameters and structural laterality covary with aging. Seventy‐five subjects drawn from a larger normal aging cohort were evaluated in terms of MRI and neuropsychological parameters at two moments (M1 and M2), 18 months apart. In this time frame, asymmetry as measured by structural laterality index (ΔLI) was stable regarding both direction and magnitude in all areas. However, a significantly higher dispersion for this variation was observed in subcortical over cortical areas. Subjects with extreme increase in rightward lateralization of the caudate revealed increased M1 to M2 Stroop interference scores, but also a worsening of general cognition (MMSE). In contrast, subjects showing extreme increase in leftward lateralization of the thalamus presented higher increase in Stroop interference scores. In conclusion, while a decline in cognitive function was observed in the entire sample, regional brain asymmetries were relatively stable. Neuropsychological trajectories were associated with laterality changes in subcortical regions.

Poor Sleep Quality Associates With Decreased Functional and Structural Brain Connectivity in Normative Aging: A MRI Multimodal Approach

Sleep is a ubiquitous phenomenon, essential to the organism homeostasis. Notwithstanding, there has been an increasing concern with its disruption, not only within the context of pathological conditions, such as neurologic and psychiatric diseases, but also in health. In fact, sleep complaints are becoming particularly common, especially in middle-aged and older adults, which may suggest an underlying susceptibility to sleep quality loss and/or its consequences. Thus, a whole-brain modeling approach to study the shifts in the system can cast broader light on sleep quality mechanisms and its associated morbidities. Following this line, we sought to determine the association between the standard self-reported measure of sleep quality, the Pittsburgh Sleep Quality Index (PSQI) and brain correlates in a normative aging cohort. To this purpose, 86 participants (age range 52–87 years) provided information regarding sociodemographic parameters, subjective sleep quality and associated psychological variables. A multimodal magnetic resonance imaging (MRI) approach was used, with whole-brain functional and structural connectomes being derived from resting-state functional connectivity (FC) and probabilistic white matter tractography (structural connectivity, SC). Brain regional volumes and white matter properties associations were also explored. Results show that poor sleep quality was associated with a decrease in FC and SC of distinct networks, overlapping in right superior temporal pole, left middle temporal and left inferior occipital regions. Age displayed important associations with volumetric changes in the cerebellum cortex and white matter, thalamus, hippocampus, right putamen, left supramarginal and left lingual regions. Overall, results suggest that not only the PSQI global score may act as a proxy of changes in FC/SC in middle-aged and older individuals, but also that the age-related regional volumetric changes may be associated to an adjustment of brain connectivity. These findings may also represent a step further in the comprehension of the role of sleep disturbance in disease, since the networks found share regions that have been shown to be affected in pathologies, such as depression and Alzheimer's disease.

Factors that positively or negatively mediate the effects of age on working memory across the adult life span

Working memory abilities significantly decrease with advancing age; hence, the search for factors that may increase or mitigate this decline is critical. Several factors have been identified that influence working memory; however, their effects have been mainly assessed separately and rarely together with other factors in the same sample. We examined 120 variables to search for factors that jointly act as mediators of working memory decay across the adult life span. A sample of 1652 healthy adults was assessed in spatial and verbal working memory domains. Structural equation modeling analyses were conducted to search for potential mediators that intervened between age and working memory. Only 14 and 10 variables reliably mediated spatial and verbal working memory, respectively. Factors from several domains remained in the models, such as individual characteristics, physiological traits, consumption habits, and regular activities. These factors are sufficiently powerful to influence working memory decline when they jointly interact, as in everyday living.

Functional Hemispheric (A)symmetries in the Aged Brain-Relevance for Working Memory

Functional hemispheric asymmetries have been described in different cognitive processes, such as decision-making and motivation. Variations in the pattern of left/right activity have been associated with normal brain functioning, and with neuropsychiatric diseases. Such asymmetries in brain activity evolve throughout life and are thought to decrease with aging, but clear associations with cognitive function have never been established. Herein, we assessed functional laterality during a working memory task (N-Back) in a healthy aging cohort (over 50 years old) and associated these asymmetries with performance in the test. Activity of lobule VI of the cerebellar hemisphere and angular gyrus was found to be lateralized to the right hemisphere, while the precentral gyrus presented left > right activation during this task. Interestingly, 1-Back accuracy was positively correlated with left > right superior parietal lobule activation, which was mostly due to the influence of the left hemisphere. In conclusion, although regions were mostly symmetrically activated during the N-Back task, performance in working memory in aged individuals seems to benefit from lateralized involvement of the superior parietal lobule.

Mediators of episodic memory decay across the adult life span

The ability to remember the details of our own experiences declines gradually as we get old. The reason for this decay has been attributed to several factors besides age, such as education, nutrient intake and health status. However, the influence of these factors has mainly been examined individually and rarely together. Here we identify those factors that jointly act as mediators of episodic memory decay across the adult life span. We examined source memory in a lifespan sample of 1557 healthy adults. A total of 70 physical, biological and lifestyle variables were measured and introduced into a structural equation model as potential mediators that intervene between age and source memory. Only 14 mediator variables reliably mediated source memory decay; notably, eight of these variables have an effect on the cardiovascular system. The model unequivocally highlights that the mediators that may impair cardiovascular functioning also impact brain resources involved in episodic memory. We identified the factors that are relevant to episodic memory decline when they interact together as occurs in real life.

Cognitive reserve as a moderator of the negative association between mood and cognition: evidence from a population-representative cohort

BACKGROUND

Cognitive reserve (CR) has been associated with better cognitive function and lower risk of depression in older people, yet it remains unclear whether CR moderates the association between mood and cognition. This study aimed to investigate whether a comprehensive indicator of CR, including education, occupation and engagement in cognitive and social activities, acts as a moderator of this association.

METHODS

This was a cross-sectional study utilising baseline data from the Cognitive Function and Ageing Study II (CFAS II), a large population-based cohort of people aged 65+ in England. Complete data on the measures of CR, mood and cognition were available for 6565 dementia-free individuals. Linear regression models were used to investigate the potential modifying effect of CR on the association between cognition and mood with adjustment for age, sex and missing data.

RESULTS

Levels of CR did moderate the negative association between mood and cognition; the difference in cognition between those with and without a clinical level mood disorder was significantly smaller in the middle (-2.28; 95% confidence interval (CI) -3.65 to -0.90) and higher (-1.30; 95% CI -2.46 to -0.15) CR groups compared with the lower CR group (-4.01; 95% CI -5.53 to -2.49). The individual components of CR did not significantly moderate the negative association between mood and cognition.

CONCLUSION

These results demonstrate that CR, indexed by a composite score based on multiple indicators, can moderate the negative association between lowered mood and cognition, emphasising the importance of continuing to build CR across the lifespan in order to maintain cognitive health.

Gene-environment interactions informing therapeutic approaches to cognitive and affective disorders

Gene-environment interactions drive experience-dependent changes in the brain that alter cognition, emotion and behaviour. Positive engagement with the environment, through novel experience and physical activity, can improve brain function, although the mechanisms mediating such experience-dependent plasticity remain to be fully elucidated. In this article, we discuss the therapeutic value of environmental stimuli, exercise and environmental enrichment (EE), for cognitive and affective disorders, with implications for the understanding and treatment of depression and anxiety disorders. We demonstrate that environmental manipulations are potential therapeutic strategies for improving outcomes in these psychiatric disorders, including beneficial impacts on cognition. We discuss how EE and exercise are therapeutic environmental interventions impacting both affective and cognitive function. Serotonergic (5-HTergic) signaling is strongly implicated in the manifestation of psychiatric disorders and regulates cognitive and emotional processing that can underpin them. Thus, we focus on evidence implicating the serotonergic system in mediating gene-environment interactions to EE and exercise. Finally, we discuss robust gene-environment interactions associated with EE and exercise interventions, and their impacts on specific brain areas, particularly the hippocampus. We focus on potential mediators of this experience-dependent plasticity, including adult neurogenesis and brain-derived neurotrophic factor (BDNF). Furthermore, we explore molecular and cellular mechanisms of experience-dependent plasticity that potentially underlie the restoration of affective and cognitive phenotypes, thus identifying novel therapeutic targets. This article is part of the Special Issue entitled "Neurobiology of Environmental Enrichment".

Decreased Complexity in Alzheimer's Disease: Resting-State fMRI Evidence of Brain Entropy Mapping

Alzheimer's disease (AD) is a frequently observed, irreversible brain function disorder among elderly individuals. Resting-state functional magnetic resonance imaging (rs-fMRI) has been introduced as an alternative approach to assessing brain functional abnormalities in AD patients. However, alterations in the brain rs-fMRI signal complexities in mild cognitive impairment (MCI) and AD patients remain unclear. Here, we described the novel application of permutation entropy (PE) to investigate the abnormal complexity of rs-fMRI signals in MCI and AD patients. The rs-fMRI signals of 30 normal controls (NCs), 33 early MCI (EMCI), 32 late MCI (LMCI), and 29 AD patients were obtained from the Alzheimer's disease Neuroimaging Initiative (ADNI) database. After preprocessing, whole-brain entropy maps of the four groups were extracted and subjected to Gaussian smoothing. We performed a one-way analysis of variance (ANOVA) on the brain entropy maps of the four groups. The results after adjusting for age and sex differences together revealed that the patients with AD exhibited lower complexity than did the MCI and NC controls. We found five clusters that exhibited significant differences and were distributed primarily in the occipital, frontal, and temporal lobes. The average PE of the five clusters exhibited a decreasing trend from MCI to AD. The AD group exhibited the least complexity. Additionally, the average PE of the five clusters was significantly positively correlated with the Mini-Mental State Examination (MMSE) scores and significantly negatively correlated with Functional Assessment Questionnaire (FAQ) scores and global Clinical Dementia Rating (CDR) scores in the patient groups. Significant correlations were also found between the PE and regional homogeneity (ReHo) in the patient groups. These results indicated that declines in PE might be related to changes in regional functional homogeneity in AD. These findings suggested that complexity analyses using PE in rs-fMRI signals can provide important information about the fMRI characteristics of cognitive impairments in MCI and AD.

Cognitive performance in healthy older adults relates to spontaneous switching between states of functional connectivity during rest

Growing evidence has shown that brain activity at rest slowly wanders through a repertoire of different states, where whole-brain functional connectivity (FC) temporarily settles into distinct FC patterns. Nevertheless, the functional role of resting-state activity remains unclear. Here, we investigate how the switching behavior of resting-state FC relates with cognitive performance in healthy older adults. We analyse resting-state fMRI data from 98 healthy adults previously categorized as being among the best or among the worst performers in a cohort study of >1000 subjects aged 50+ who underwent neuropsychological assessment. We use a novel approach focusing on the dominant FC pattern captured by the leading eigenvector of dynamic FC matrices. Recurrent FC patterns - or states - are detected and characterized in terms of lifetime, probability of occurrence and switching profiles. We find that poorer cognitive performance is associated with weaker FC temporal similarity together with altered switching between FC states. These results provide new evidence linking the switching dynamics of FC during rest with cognitive performance in later life, reinforcing the functional role of resting-state activity for effective cognitive processing.

Discriminant power of socio-demographic characteristics and mood in distinguishing cognitive performance clusters in older individuals: a cross-sectional analysis

OBJECTIVES

Identification of predictors of cognitive trajectories has been a matter of concern on aging research. For this reason, it is of relevance to infer cognitive profiles based on rapid screening variables in order to determine which individuals will be more predisposed to cognitive decline.

METHOD

In this work, a linear discriminant analysis (LDA) was conducted with socio-demographic variables and mood status as predictors of cognitive profiles, computed in a previous sample, based on different cognitive dimensions. Data were randomly split in two samples. Both samples were representative of the Portuguese population in terms of gender, age and education. The LDA was performed with one sample (n = 506, mean age 65.7 ± 8.98 years) and tested in the second sample (n = 548, mean age 68.5 ± 9.3 years).

RESULTS

With these variables, we were able to achieve an overall hit rate of 65.9%, which corresponds to a significant increment in comparison to classification by chance.

CONCLUSION

Although not ideal, this model may serve as a relevant tool to identify cognitive profiles based on a rapid screening when few variables are available.

Influence of schooling and age on cognitive performance in healthy older adults

Few studies have examined the influence of a low level of schooling on age-related cognitive decline in countries with wide social and economic inequalities by using the Cambridge Automated Neuropsychological Test Battery (CANTAB). The aim of the present study was to assess the influence of schooling on age-related cognitive decline using unbiased cognitive tests. CANTAB allows cognitive assessment across cultures and education levels with reduced interference of the examiner during data acquisition. Using two-way ANOVA, we assessed the influences of age and education on test scores of old adults (61–84 years of age). CANTAB tests included: Visual Sustained Attention, Reaction Time, Spatial Working Memory, Learning and Episodic Memory. All subjects had a minimum visual acuity of 20/30 (Snellen Test), no previous or current history of traumatic brain/head trauma, stroke, language impairment, chronic alcoholism, neurological diseases, memory problems or depressive symptoms, and normal scores on the Mini Mental State Examination (MMSE). Subjects were grouped according to education level (1 to 7 and ≥8 years of schooling) and age (60–69 and ≥70 years). Low schooling level was associated with significantly lower performance on visual sustained attention, learning and episodic memory, reaction time, and spatial working memory. Although reaction time was influenced by age, no significant results on post hoc analysis were detected. Our findings showed a significantly worse cognitive performance in volunteers with lower levels of schooling and suggested that formal education in early life must be included in the preventive public health agenda. In addition, we suggest that CANTAB may be useful to detect subtle cognitive changes in healthy aging.

Adult Body Height Is a Good Predictor of Different Dimensions of Cognitive Function in Aged Individuals: A Cross-Sectional Study

Background: Adult height, weight, and adiposity measures have been suggested by some studies to be predictors of depression, cognitive impairment, and dementia. However, the presence of confounding factors and the lack of a thorough neuropsychological evaluation in many of these studies have precluded a definitive conclusion about the influence of anthropometric measures in cognition and depression. In this study we aimed to assess the value of height, weight, and abdominal perimeter to predict cognitive impairment and depressive symptoms in aged individuals.

Methods and Findings: Cross-sectional study performed between 2010 and 2012 in the Portuguese general community. A total of 1050 participants were included in the study and randomly selected from local area health authority registries. The cohort was representative of the general Portuguese population with respect to age (above 50 years of age) and gender. Cognitive function was assessed using a battery of tests grouped in two dimensions: general executive function and memory. Two-step hierarchical multiple linear regression models were conducted to determine the predictive value of anthropometric measures in cognitive performance and mood before and after correction for possible confounding factors (gender, age, school years, physical activity, alcohol consumption, and smoking habits). We found single associations of weight, height, body mass index, abdominal perimeter, and age with executive function, memory and depressive symptoms. However, when included in a predictive model adjusted for gender, age, school years, and lifestyle factors only height prevailed as a significant predictor of general executive function (β = 0.139; p < 0.001) and memory (β = 0.099; p < 0.05). No relation was found between mood and any of the anthropometric measures studied.

Conclusions and Relevance: Height is an independent predictor of cognitive function in late-life and its effects on the general and executive function and memory are independent of age, weight, education level, gender, and lifestyle factors. Altogether, our data suggests that modulators of adult height during childhood may irreversibly contribute to cognitive function in adult life and that height should be used in models to predict cognitive performance.

The functional connectome of cognitive reserve

Cognitive Reserve (CR) designates the brain's capacity to actively cope with insults through a more efficient use of its resources/networks. It was proposed in order to explain the discrepancies between the observed cognitive ability and the expected capacity for an individual. Typical proxies of CR include education and Intelligence Quotient but none totally account for the variability of CR and no study has shown if the brain's greater efficiency associated with CR can be measured. We used a validated model to estimate CR from the residual variance in memory and general executive functioning, accounting for both brain anatomical (i.e., gray matter and white matter signal abnormalities volume) and demographic variables (i.e., years of formal education and sex). Functional connectivity (FC) networks and topological properties were explored for associations with CR. Demographic characteristics, mainly accounted by years of formal education, were associated with higher FC, clustering, local efficiency and strength in parietal and occipital regions and greater network transitivity. Higher CR was associated with a greater FC, local efficiency and clustering of occipital regions, strength and centrality of the inferior temporal gyrus and higher global efficiency. Altogether, these findings suggest that education may facilitate the brain's ability to form segregated functional groups, reinforcing the view that higher education level triggers more specialized use of neural processing. Additionally, this study demonstrated for the first time that CR is associated with more efficient processing of information in the human brain and reinforces the existence of a fine balance between segregation and integration. Hum Brain Mapp 37:3310–3322, 2016.. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

Connecting the dots on health inequalities--a systematic review on the social determinants of health in Portugal

INTRODUCTION

Health inequalities are recognised as a public health issue worldwide, but only a few countries have developed national strategies to monitor and reduce them. Despite its considerable health inequalities, Portugal seems to lack a systematic strategy to tackle them, possibly due to the absence of organised evidence on the issue. We performed a systematic review that aimed to describe the available evidence on social inequalities in health in Portugal, in order to contribute towards a comprehensive and focused strategy to tackle them.

METHODS

We followed the PRISMA guidelines and searched Scopus, Web of Science and PubMed for studies that looked at the association between a measure of socioeconomic status and a health outcome in the Portuguese resident population since the year 2000. We excluded health behaviours and healthcare use from our search. We performed a qualitative description of the results.

RESULTS

Seventy-one publications were selected, all reporting observational analyses, most of them using cross-sectional data. These publications showed strong evidence for health inequalities related to education and gender, chiefly for obesity, self-rated health and mental health.

CONCLUSIONS

Analysis of the eligible publications showed that current research does not seem to have consistently covered the link between health and key Portuguese social problems. A strategy focusing on the monitoring of most prevalent diseases, most determining socioeconomic factors and vulnerable populations would be crucial to guide academic research in a country in which health inequalities are so ubiquitous and deeply rooted.

REGISTRATION

This systematic review is not registered.

Applicability of the Telephone Interview for Cognitive Status (Modified) in a community sample with low education level: association with an extensive neuropsychological battery

OBJECTIVE

To explore the applicability of a Portuguese (PT) version of the Telephone Interview for Cognitive Status (TICS), with a delayed recall item [modified (M)], here termed TICSM-PT, against an extensive (in-person) battery of neuropsychological instruments, in a sample of older individuals with low educational level and without clinically manifest/diagnosed cognitive impairment.

METHODS

Following translation/back-translation and pilot testing in 33 community dwellers, 142 community dwellers aged 52 to 84 years (mean = 67.45, SD = 7.91) were selected from local health care centres for the study (convenience sampling; stratified age and gender). Cronbach's alpha was used to assess internal consistency, and convergent validity was evaluated through the correlation between TICSM-PT and the Mini Mental State Examination (MMSE), as well as with a comprehensive battery of cognitive instruments. Divergent/discriminant validity was assessed through a battery of psychological instruments. The receiver operating curve was determined for TICSM-PT to classify participants with and without possible indication of cognitive impairment.

RESULTS

TICSM-PT showed a satisfactory internal consistency (Cronbach's alpha = 0.705), convergent validity and discriminant validity. TICSM-PT presented a positive association with the global cognitive measures Mini Mental State Examination and the Montreal Cognitive Assessment, and also with most neuropsychological parameters. Receiver operating curve curves presented a sensitivity of 90.6% and specificity of 73.7%. The area under the curve statistic yielded a threshold score equal or below 13.5 for cognitive impairment.

CONCLUSION

TICSM-PT is a practical tool for rapid cognitive assessment among older individuals with low educational background.

Does cognitive reserve moderate the association between mood and cognition? A systematic review

The evidence regarding the association between mood and cognitive function is conflicting, suggesting the involvement of moderating factors. This systematic review aimed to assess whether cognitive reserve moderates the association between mood and cognition in older people. Cognitive reserve was considered in terms of the three key proxy measures – educational level, occupation, and engagement in cognitively stimulating leisure activities – individually and in combination. Sixteen studies representing 37,101 participants were included in the review. Of these, 13 used a measure of education, one used a measure of occupation, two used a measure of participation in cognitively stimulating activities, and one used a combination of these. In general, cognitive reserve moderated the association between mood and cognition, with a larger negative association between mood and cognition in those with low cognitive reserve than in those with high cognitive reserve. Further research utilizing multiple proxy measures of cognitive reserve is required to elucidate the associations.

The Bounds Of Education In The Human Brain Connectome

Inter-individual heterogeneity is evident in aging; education level is known to contribute for this heterogeneity. Using a cross-sectional study design and network inference applied to resting-state fMRI data, we show that aging was associated with decreased functional connectivity in a large cortical network. On the other hand, education level, as measured by years of formal education, produced an opposite effect on the long-term. These results demonstrate the increased brain efficiency in individuals with higher education level that may mitigate the impact of age on brain functional connectivity.

Effector memory CD4(+) T cells are associated with cognitive performance in a senior population

Objective:

Immunosenescence and cognitive decline are common markers of the aging process. Taking into consideration the heterogeneity observed in aging processes and the recently described link between lymphocytes and cognition, we herein explored the possibility of an association between alterations in lymphocytic populations and cognitive performance.

Methods:

In a cohort of cognitively healthy adults (n = 114), previously characterized by diverse neurocognitive/psychological performance patterns, detailed peripheral blood immunophenotyping of both the innate and adaptive immune systems was performed by flow cytometry.

Results:

Better cognitive performance was associated with lower numbers of effector memory CD4⁺ T cells and higher numbers of naive CD8⁺ T cells and B cells. Furthermore, effector memory CD4⁺ T cells were found to be predictors of general and executive function and memory, even when factors known to influence cognitive performance in older individuals (e.g., age, sex, education, and mood) were taken into account.

Conclusions:

This is the first study in humans associating specific phenotypes of the immune system with distinct cognitive performance in healthy aging.

Ability of university-level education to prevent age-related decline in emotional intelligence

Numerous studies have suggested that educational history, as a proxy measure of active cognitive reserve, protects against age-related cognitive decline and risk of dementia. Whether educational history also protects against age-related decline in emotional intelligence (EI) is unclear. The present study examined ability EI in 310 healthy adults ranging in age from 18 to 76 years using the Mayer–Salovey–Caruso Emotional Intelligence Test (MSCEIT). We found that older people had lower scores than younger people for total EI and for the EI branches of perceiving, facilitating, and understanding emotions, whereas age was not associated with the EI branch of managing emotions. We also found that educational history protects against this age-related EI decline by mediating the relationship between age and EI. In particular, the EI scores of older adults with a university education were higher than those of older adults with primary or secondary education, and similar to those of younger adults of any education level. These findings suggest that the cognitive reserve hypothesis, which states that individual differences in cognitive processes as a function of lifetime intellectual activities explain differential susceptibility to functional impairment in the presence of age-related changes and brain pathology, applies also to EI, and that education can help preserve cognitive-emotional structures during aging.