Volume In Older Adults Research Articles

Association between perceived stress and brain structure volumes in older adults without late-life depression: a key role for the thalamus?

Association between perceived stress and brain structure volumes in older adults without late-life depression: a key role for the thalamus?

Insulin and hippocampal subregion volume in older adults

AbstractBackgroundType 2 diabetes (DM) is a risk factor for Alzheimer's disease (AD) and other dementias. DM, which is more common in Mexican Americans (MA) than non‐Hispanic Whites (NHW), is associated with high blood glucose levels and often with hyperinsulinemia. Hippocampal volume is an early neuroimaging marker of AD. We examined the relationship of blood insulin with hippocampal subregion volumes in MA and NHW.MethodIn a sample of 1588 older adults without dementia (age: 50‐92 years; 826 MA, 762 NHW; 387 DM, 1201 non‐DM; 1344 cognitively normal, 244 mild cognitive impairment; 613M/975F) from the Health and Aging Brain Study ‐ Health Disparities (HABS‐HD) cohort, we assessed whether fasting plasma insulin and glucose levels were associated with the volume of left and right hippocampal body subregions (CA1, CA23DG, subiculum) using hippocampal high resolution 3T MRI scans (Siemens 3T). We further examined the significant insulin relationship with CA23DG volume by ethnicity and diabetes diagnostic group. We used a multiple linear regression model, covarying for age, sex, cognitive diagnosis, diabetic status, years of education, number of MRI slices segmented, and intracranial volume. All p values were FDR corrected for multiple comparisons across regions.ResultHigher insulin levels were associated with a smaller volume in right and left CA23DG (right: FDR p=0.015, left: FDR p=0.015) across all participants. Glucose levels were not significantly associated with hippocampal subregion volume (Table 1). When we further investigated the significant relationship between insulin and CA23DG volume by ethnic group and diabetic status, we found that higher insulin was associated with lower CA23DG volume in NHW (right: p=0.014, left: p=0.013), MA (right only: p=0.034, left: p=0.115), and in non‐diabetics (right: p=0.027, left trend: p=0.056) (Figure 1).ConclusionHigher insulin levels were associated with lower CA23DG volume in older adults without dementia, with the strength of the negative association between blood insulin levels and hippocampal subfield volume varying by diabetic status.

Physical Activity Level Moderates the Association Between Response Inhibition and Anterior Cingulate Cortex Volume in Older Adults

AbstractBackgroundAging is generally associated with a decline in executive function, a cognitive domain that is critical to functional independence. Response inhibition is an executive process that contributes to anticipation, planning, and goal setting. The anterior cingulate cortex (ACC) is a key brain structure that supports response inhibition and shows gray matter loss with age. Evidence suggests that both response inhibition performance and the Anterior Cingulate Cortex (ACC) are responsive to exercise training. Whether physical activity moderates the relationship between response inhibition and the ACC in older adults is unknown.MethodA cross‐sectional analysis of a subset of community‐dwelling older adults enrolled in a 3‐arm, 8‐week proof of concept randomized control trial of computerized cognitive training, with or without exercise, who completed T1 magnetic resonance imaging (MRI) at baseline. Of the 68 MRI participants, 11 were removed from this analysis due to poor scan quality. Response inhibition was measured using the Flanker Task from the NIH Toolbox Cognitive Battery. Participants were split into either a high or low physical activity groups determined by their median Physical Activity Scale for the Elderly (PASE) score. Caudal and rostral ACC volumes were segmented and quantified using FreeSurfer. To assess for moderation, we performed linear regressions with age‐adjusted Flanker Task score as the dependent variable, and ACC volume, high/low PASE, and the interaction of ACC volume * high/low PASE as independent variables.ResultPhysical activity level significantly moderated the association between left caudal anterior cingulate cortex (LCACC) volume and age‐adjusted Flanker Task score, (β = –6.428, t(53) = ‐2.075, p < .05). Among those with low physical activity levels (n = 30), greater LCACC volume was associated with better response inhibition (r = 0.44, p = .01) while there was no association among those with high physical activity levels (n = 27; r = ‐0.13; p = .52).ConclusionHigher physical activity may mitigate the negative effects of age‐related gray matter loss in the ACC on response inhibition performance in community‐dwelling older adults.

Hippocampus and temporal pole functional connectivity is associated with age and individual differences in autobiographical memory

Recollection of one's personal past, or autobiographical memory (AM), varies across individuals and across the life span. This manifests in the amount of episodic content recalled during AM, which may reflect differences in associated functional brain networks. We take an individual differences approach to examine resting-state functional connectivity of temporal lobe regions known to coordinate AM content retrieval with the default network (anterior and posterior hippocampus, temporal pole) and test for associations with AM. Multiecho resting-state functional magnetic resonance imaging (fMRI) and autobiographical interviews were collected for 158 younger and 105 older healthy adults. Interviews were scored for internal (episodic) and external (semantic) details. Age group differences in connectivity profiles revealed that older adults had lower connectivity within anterior hippocampus, posterior hippocampus, and temporal pole but greater connectivity with regions across the default network compared with younger adults. This pattern was positively related to posterior hippocampal volumes in older adults, which were smaller than younger adult volumes. Connectivity associations with AM showed two significant patterns. The first dissociated connectivity related to internal vs. external AM across participants. Internal AM was related to anterior hippocampus and temporal pole connectivity with orbitofrontal cortex and connectivity within posterior hippocampus. External AM was related to temporal pole connectivity with regions across the lateral temporal cortex. In the second pattern, younger adults displayed temporal pole connectivity with regions throughout the default network associated with more detailed AMs overall. Our findings provide evidence for discrete ensembles of brain regions that scale with systematic variation in recollective styles across the healthy adult life span.

Objective Physical Activity Accumulation and Brain Volume in Older Adults: An MRI and Whole-Brain Volume Study.

A decrease in brain volume (ie, brain atrophy) is a marker of cognitive health in older adults. Insufficient weekly accumulation of moderate and vigorous physical activity (MVPA) has been associated with lower brain volume. As this association has been established for a small number of brain areas and structures and atrophy rates seem to be nonuniform between them, more comprehensive analyses are warranted. We compared the volume of 71 brain areas and structures in 45 older adults who met and did not meet objectively measured MVPA recommendations. In addition, we used multiple regression models to determine whether cardiorespiratory fitness (VO2PEAK), MVPA, and health-related risk factors could affect the atrophy of brain areas and structures. An accelerometer (GT9-X ActiGraph) was worn for 7days. Participants were then classified into 2 groups: <150 minutes MVPA (<150'MVPA; n=20) and ≥150 minutes MVPA (≥150'MVPA; n=25) per week. Older adults who accumulated ≥150'MVPA per week had significantly higher absolute and relative (%of intracranial volume) volumes of 39 and 9 brain areas and structures, respectively, than those who accumulated <150'MVPA per week. Higher VO2PEAK seems to be a key predictor of the atrophy of brain areas and structures. In conclusion, meeting weekly physical activity recommendations seems to have a widespread effect on preserving the volume of more than 30 brain areas and structures in older adults. VO2PEAK seems to be the most frequent and important predictor of brain volume preservation.

Light intensity physical activity is beneficially associated with brain volume in older adults with high cardiovascular risk.

BackgroundOlder people with high cardiovascular risk, including those without cardiovascular diseases, are an at-risk population for dementia. Regular physical activity is generally recommended to maintain brain health; however, the optimal intensity of physical activity for maintaining brain volume in older adults with cardiovascular risk remains unclear. We examined the associations between intensity-specific physical activity and brain volume stratified by absolute cardiovascular risk level in older adults without cardiovascular diseases.Methods and resultsThis cross-sectional study involved 725 community-dwelling older Japanese adults without cardiovascular diseases. We estimated absolute cardiovascular risk using the World Health Organization risk estimation charts, which include variables such as age, sex, diabetes mellitus, smoking, systolic blood pressure, and total cholesterol, and stratified cardiovascular risk level into three risk categories: low (≤ 9%), moderate (10–14%), and high (≥15%). We measured daily physical activity using a triaxial accelerometer, and calculated the average time spent in moderate-to-vigorous intensity physical activity (MVPA) and light intensity physical activity (LPA). We performed brain T1-weighted magnetic resonance imaging and calculated the volume of the cortical gray matter, subcortical gray matter, and cerebral white matter, using the FreeSurfer software. In the overall sample, multivariable linear regression analysis showed that greater MVPA was significantly associated with greater volume of the cortical gray matter and cerebral white matter, and greater LPA was significantly associated with greater volume of the cerebral white matter. Additionally, in the analysis of the sample stratified by absolute cardiovascular risk level, cerebral white matter volume was significantly associated with both MVPA and LPA in the high cardiovascular risk group.ConclusionsThe association between physical activity and brain volume differed according to cardiovascular risk level in community-dwelling older adults. In a population at high cardiovascular risk, maintaining or increasing LPA might be a practical and achievable strategy for healthy brain aging.

Effect of Preoperative Oral Carbohydrates on Insulin Resistance in Older Adults Who Underwent Total Hip or Knee Arthroplasty: A Prospective Randomized Trial.

Preoperative carbohydrate drinks are recommended to reduce fasting time before surgery. Older adults are at risk of pulmonary aspiration and hyperglycemia after consuming carbohydrate drinks because of increased insulin resistance and delayed gastric emptying. We investigated the effects of oral carbohydrate drinks on perioperative insulin resistance, metabolic responses, and gastric volume in older adults. Fifty-six patients (aged more than 65 years) were randomly assigned to the control or carbohydrate (CHO) group. The CHO group received 400 mL of a carbohydrate drink 2 to 3 hours before anesthesia. The control group was allowed clear fluid intake 2 hours before anesthesia. Blood glucose and insulin levels were measured before intake of the carbohydrate drink and 1 hour postoperatively. Gastric volume was measured before spinal anesthesia. Insulin resistance was calculated using the homeostasis model assessment for insulin resistance. Homeostasis model assessment for insulin resistance was not different between the control and CHO groups preoperatively (2.5 versus 3.3, P = 0.156) or postoperatively (2.6 versus 2.4, P = 0.817). Preoperative gastric volume was comparable between the control and CHO groups (35.5 versus 30.8 mL, P = 0.696). Preoperative oral consumption of carbohydrates did not affect insulin resistance or gastric volume in older adults undergoing total knee or hip arthroplasty. Preoperative carbohydrate loading is safe in older adults undergoing total knee or hip arthroplasty. The data that support the findings of this study are available from the corresponding author on reasonable request. ClinicalTrials.gov (No. NCT04206189).

Kundalini Yoga Intervention Increases Hippocampal Volume in Older Adults: A Pilot Randomized Controlled Trial.

Among a rapidly aging population, there is increased need for neuroprotective interventions promoting healthy neurological aging. Mind-body interventions, such as Kundalini yoga, are actively being explored as accessible means to encourage healthy aging. However, little remains known about the neurobiological effects of Kundalini yoga. This pilot randomized-controlled trial (RCT) examined the potential neuroprotective effects of Kundalini yoga in older adults. We conducted an RCT with 11 healthy meditation-naïve older adults. Participants were randomized to a Kundalini yoga or psychoeducation intervention. Structural magnetic resonance imaging data were obtained at baseline and 12-week follow-up. The primary outcome measure was gray matter volume of the bilateral hippocampi and bilateral posterior cingulate cortex. We found significant right hippocampal volume increases specific to the Kundalini yoga group (P = 0.034, ηp 2 = 0.408). These findings provide initial neurobiological support for the neuroprotective effects of Kundalini yoga.

Association between serum free hemoglobin level and cerebral white matter hyperintensity volume in older adults

The association between serum free hemoglobin (sfHb) level and white matter hyperintensity (WMH) volume is controversial. This study is to examine this association considering nonlinearity, sex dimorphism, and WMH type. We enrolled 704 older adults among the participants of the Korean Longitudinal Study on Cognitive Aging and Dementia and visitors to the Dementia Clinic of Seoul National University Bundang Hospital. We measured sfHb level in the venous blood and WMH volume (VWMH) using fluid-attenuated inversion recovery magnetic resonance images. The association between sfHb level and periventricular VWMH was linear in men (linear regression; β = − 0.18, p = 0.006) and U-shaped in women (restricted cubic spline; F = 6.82, p < 0.001). sfHb level was not associated with deep VWMH in either sex. These findings were also observed in participants without anemia. To conclude, sfHb level is associated with periventricular VWMH in older adults of both sexes. Maintaining an optimal sfHb level may contribute to the prevention of WMH.

EFEITO DO TREINO DE FORÇA NA HIPERTROFIA MUSCULAR EM IDOSOS SAUDÁVEIS: UMA REVISÃO SISTEMÁTICA

OBJECTIVE: To systematically summarize the literature considering studies that address strength training and its effects on muscle hypertrophy in healthy older people. METHODS: The search was developed on the PubMed platform considering the PICOS strategy. The search date of the selected studies included the last 5 years (01.01.2017 to 07.21.2021). Studies in any language were considered. As eligibility criteria, the studies were required to contain: healthy older people; interventions with strength exercises; outcomes with hypertrophy measures (MRI, ultrasound, etc). RESULTS: In total, 14 studies were included, totaling 470 older individuals (296 participants in the experimental group and 174 participants in the control group), aged between 60 and 80 years. The strength training interventions took place over between 4 and 30 weeks, with sessions from 1 to 7 times a week. Tests of balance, measurement of muscle temperature, capacity and functional performance, and strength tests were also carried out, with the most common being the 1 repetition maximum test (1RM). For the hypertrophy measurements, dual energy X-ray (DXA), ultrasound, bioelectrical impedance, and computed tomography were used. The analyzed studies showed a significant increase in muscle volume in the intervention groups when compared to control groups (follow-up or comparison). However, studies with comparison groups (another strength training strategy or protocol) also showed increases in muscle volume, with no differences between groups. CONCLUSION: Strength training is effective in promoting improvements in muscle volume in older adults.

The relationship between cardiovascular risk and lifestyle activities on hippocampal volumes in normative aging.

Despite the life-course perspective of popular aging models, few studies on healthy aging to date have examined both younger and older adulthood. The current study examined how cumulative vascular risk factors and self-reported levels of physical, social, and cognitive activity are associated with differences in hippocampal volumes in healthy younger and older adults. 34 neurologically healthy participants were separated into two age cohorts: a younger adult group (age 25-35, n = 17) and an older adult group (age 65-82, n = 17). Participants underwent a 3 T T1 MRI and completed a series of questionnaires. Voxel-based morphometry examined whole-brain grey matter density differences between groups. Hippocampal volumes were computed. Analyses examined the association between hippocampal volumes, cumulative vascular risk, and self-reported levels of physical, social, and cognitive activity, both within and across groups. Between-group comparisons revealed greater cortical atrophy in older relative to young adults in regions including the left and right hippocampus and temporal fusiform cortex. Across-group analyses revealed a significant negative association between cardiovascular risk scores and bilateral hippocampal volumes across age groups. A significant negative association was identified between frequency of social activities and bilateral hippocampal volumes in older adults only. No significant associations were found between left or right hippocampal volumes and total, cognitive, or physical activities in both within- and across-group analyses. Greater cumulative vascular risk is associated with smaller hippocampal volumes across age cohorts. Findings suggest that social activities with low cognitive load may not be beneficial to structural brain outcomes in older age.

Brain Derived Neurotrophic Factor Interacts with Diabetes Status to Influence Memory and Hippocampal Volume in Older Adults

Brain Derived Neurotrophic Factor Interacts with Diabetes Status to Influence Memory and Hippocampal Volume in Older Adults

Evaluating associations of RNFL thickness and multifocal VEP with cognitive assessment and brain MRI volumes in older adults: Optic nerve decline and cognitive change (ONDCC) initiative.

To examine the relationships of retinal structural (optical coherence tomography) and visual functional (multifocal visual evoked potentials, mfVEP) indices with neuropsychological and brain structural measurements in healthy older subjects. 95 participants (mean (SD) age 68.1 (9.0)) years were recruited in the Optic Nerve Decline and Cognitive Change (ONDCC) study in this observational clinical investigation. OCT was conducted for retinal nerve fibre layer (RNFL) and mfVEP for amplitude and latency measurements. Participants undertook neuropsychological tests for cognitive performance and MRI for volumetric evaluation of various brain regions. Generalised estimating equation models were used for association analysis (p < 0.05). The brain volumetric measures including total grey matter (GM), cortex, thalamus, hippocampal and fourth ventricular volumes were significantly associated with global and sectoral RNFL. RNFL thickness correlated with delayed recalls of California verbal learning test (CVLT) and Rey complex figure test (RCFT). The mfVEP amplitudes associated with cerebral white matter (WM) and cingulate GM volumes in MRI and CVLT, RCFT and trail making test outcomes. A significant association of mfVEP latency with logical memory delayed recall and thalamus volume was also observed. Our results suggested significant association of specific RNFL and mfVEP measures with distinctive brain region volumes and cognitive tests reflecting performance in memory, visuospatial and executive functional domains. These findings indicate that the mfVEP and RNFL measurements may parallel brain structural and neuropsychological measures in the older population.

Thalamic abnormalities in older adults with remitted early-onset depression using structural magnetic resonance imaging

BackgroundThe thalamus is a key diencephalic structure involved in major depressive disorder (MDD). Studies have consistently revealed abnormalities in thalamic volumes in older adults with late-onset depression (LOD), however abnormalities in older adults with early-onset depression (EOD) have not yet been well-studied. MethodsFifty-nine euthymic participants with a history of EOD and fifty-nine matched comparison participants without a lifetime history of depression underwent neuroimaging, medical and neuropsychological assessments. Thalamic volumes were compared between groups. To investigate the previously-proposed right hemispheric (RH) dominance theory of MDD, we explored the bilateral, right and left hemispheric (LH) thalamic volumes. Multiple regression analyses were used to evaluate between-group and within-group effects. Correlational analyses examined associations between group and cognitive performance. ResultsRelative to the comparison group, those with EOD had significantly larger bilateral, LH and RH thalamic volumes. Those with EOD, those who were younger, and those who had fewer years of education demonstrated larger bilateral and LH thalamic volumes. For RH thalamic volumes, those with EOD and those who were younger demonstrated larger RH thalamic volumes. EOD within-group models were also run to assess associations between relevant depression variables. The results showed that only age was significant for bilateral and RH thalamic volumes. For the LH thalamic volumes, the model was not significant. No significant correlations were found between cognitive performance and EOD groups. ConclusionOlder adults with a history of EOD showed significantly larger bilateral, RH and LH thalamic volumes. Further research is needed to delineate potential underlying mechanisms of this change.

Associations Between Perceived Fatigability and Amyloid Status in the Baltimore Longitudinal Study of Aging

Higher level of and greater longitudinal increase in perceived fatigability are linked to cognitive decline and lower brain volumes in older adults. However, it remains unclear whether perceived fatigability is associated with Alzheimer’s disease-related brain pathology. In the BLSA, 163 participants without neurological disease or cognitive impairment (aged 74.7+/-8.4 years, 45% men) were assessed for perceived fatigability using rating of perceived exertion after a 5-minute (0.67 m/s) treadmill walk and Aß burden using 11C-Pittsburgh compound B (PiB) positron emission tomography. Forty-four participants were PiB+ based on a mean cortical distribution volume ratio (DVR) cut point of 1.066. After adjusting for demographics, body composition, comorbidities and ApoE-e4, higher perceived fatigability was not associated with PiB+ status (OR=0.84; 95% CI: 0.69, 1.05). Results suggest perceived fatigability may contribute to cognitive decline through pathways other than Aß pathology. Future studies should target other mechanisms linking perceived fatigability and cognitive decline.

New insights into the genetics of subcortical volumes across the adult lifespan

AbstractBackgroundSubcortical brain structures play a key role in pathological processes of many age‐related neurodegenerative disorders. Mounting evidence suggests that factors already present at an early age play a crucial role in the development of common late‐life neurological diseases, including genetic factors that can influence both brain maturation and neurodegeneration.Using large population‐based brain imaging datasets across the adult lifespan, we aimed to identify whether genetic loci associated with subcortical brain structures in older persons also show significant association with the same structures in early adulthood and explore underlying genes using transcriptome‐wide association studies (TWAS).MethodWe first tested variants, previously identified in genome‐wide association study (GWAS) of subcortical volumes in older adults, in young adults (i‐Share cohort, 18‐35y) individually and aggregated in genetic risk scores (GRS). We conducted a TWAS using the summary statistics from the GWAS of subcortical volumes. For the significant signals, we generated gene expression scores in i‐Share and tested them in association with subcortical volumes.ResultWe observed that GRS for smaller caudate nucleus and putamen volume in older adults were associated with smaller volumes of the same structures in young adults. Individually, ten independent loci associated with subcortical volumes in older adults also showed associations with the corresponding volume in young adults, with the strongest association between a variant near KTN1 and putamen volume. In TWAS, expression of several genes in brain tissues was significantly associated with caudate nucleus, putamen and pallidum volumes both in older and young adults, pointing to biological pathways underlying structural brain changes across the adult lifespan, with particularly strong evidence for a causal implication of MYLK2 and TUFM, in relation with caudate nucleus and putamen volume. We observed an association of genetically predicted Alzheimer’s disease with smaller volumes of most subcortical structures in older adults, but not in young adults.ConclusionOur findings provide novel insight into the genetic determinants of changes in subcortical brain structures across the adult lifespan. Further research is needed to decipher the underlying biological mechanisms and inform prevention strategies for common late life neurological diseases.

Does brain volume explain the difference in Alzheimer’s disease diagnosis risk between men and women? Results from analyses of four research cohorts

AbstractBackgroundWomen are more likely than men to be diagnosed Alzheimer’s disease (AD) despite recent biomarker studies demonstrating no significant difference in prevalence of AD pathology between men and women. Given that larger brain volume has been shown to be protective against progression of AD symptoms, we hypothesized that sex‐based differences in brain volume may modify the risk of AD dementia and thus explain the difference in AD diagnosis risk between males and females.MethodWe describe sex‐based differences in brain volume in a well‐characterized and socioculturally and clinically homogenous sample of older adults screening for a clinical trial. To test our hypotheses, we analyze cross‐sectional data from four distinct research cohorts: Rush Alzheimer’s Disease Research Center, Mayo Clinic Study of Aging, National Alzheimer’s Coordinating Center Uniform Data Set, Alzheimer’s Disease Neuroimaging Initiative. We use two‐stage general linear models with binomial family and log link to estimate risk of AD diagnosis attributable to self‐report sex and brain volume. In step two, an interaction‐term for sex and brain volume is entered to test how the main effect for self‐report sex changes. Multivariable models control for age and race.ResultsWe will characterize sex‐based differences in brain volume in older adults using visual summaries, descriptive statistics, and estimates of effect. This information will be compared to other published estimates of sex‐based differences in brain volume.We expect that both self‐report sex and brain volume will show independent associations with AD diagnosis risk. However, in interaction analyses, brain volume will remain statistically significant while self‐report sex no longer shows an independent association with AD diagnosis risk. We will report model estimates from these analyses.ConclusionThe study results will help elucidate brain volume’s role in contributing to sex‐based disparities in AD diagnosis. Results from analyses of four distinct data sources will lend strength to conclusions related to this novel hypothesis. They will also help advance knowledge about the character of sex‐based differences in cognitively typical older adults. Moreover, the results will help inform future research to elucidate AD mechanisms and discover drivers of sex‐based disparities in AD.

Thalamic abnormalities in older adults with early‐onset depression using structural magnetic resonance imaging

AbstractBackgroundThe thalamus is a key diencephalic structure involved in major depressive disorder (MDD). In particular, studies have consistently revealed abnormalities in thalamic volumes in older adults with late‐onset depression (LOD). However, similar abnormalities in older adults with early‐onset depression (EOD) have not been well studied.MethodFifty‐nine euthymic participants with a history of EOD and fifty‐nine matched comparison participants without a lifetime history of depression underwent neuroimaging, medical and neuropsychological assessments. Thalamic volumes were compared between groups. Due to the right hemispheric (RH) dominance theory of MDD, we explored both bilateral and right hemispheric thalamic volumes. Multiple regression analyses were used to evaluate between‐group and within‐group effects. A correlational analysis examined associations between group and cognitive performance.ResultRelative to the comparison group, those with EOD had significantly larger bilateral and RH thalamic volumes. Those with EOD, those who were younger, and those who had fewer years of education, demonstrated larger bilateral thalamic volumes. When split by group (EOD vs comparison group), only age remained significantly different for those with EOD. For RH volumes, those with EOD and those who were younger demonstrated larger RH thalamic volumes. When split by group, the results showed that age only was significant for both groups. No significant correlations were found between cognitive performance and EOD groups.ConclusionOlder adults with a history of EOD showed significantly larger bilateral and RH thalamic volumes. Further research is needed to further elucidate the underlying mechanism of this change.

Study protocol: SOcial LImitations Turn Up DEmentia (SOLITUDE)—Impact of COVID‐19 social isolation on patients’ cognition and mental health and on carers’ wellbeing

BackgroundSocial isolation and loneliness are both known to exert detrimental effects on mental health and cognitive functioning, as well as on medial temporal lobe volume in older adults. Reduced social interactions have also been found to increase the risk of cognitive decline and dementia in older people. Since restrictions to social contacts have been imposed to tackle the current Coronavirus Disease 2019 (COVID‐19) pandemic, this study aims to investigate the long‐term impact of the resulting social isolation on people with mild dementia and their carers.MethodThis study has been implemented using a multi‐centre longitudinal observational design to monitor mental health (9‐item Patient Health Questionnaire and Neuropsychiatric Inventory Questionnaire), cognitive performance (telephone Mini‐Mental State Examination and Telephone Assessment of Cognitive Function) and quality of life (Quality of Life in Alzheimer's Disease) of patients with mild dementia due to neurodegenerative aetiologies, as well as carers’ burden (12‐item Zarit Burden Interview). Additionally, a structured interview is included to assess the potential impact of social isolation on everyday functioning of patients and carers. Participants are assessed telephonically at three time‐points: baseline and two follow‐ups after 3 and 6 months.ResultSix centres across the UK have confirmed capacity and capability to recruit up to eighty participants. Between September and December 2020, twenty‐nine participants have been recruited across different sites and completed the baseline assessment. Moreover, nine participants have already completed the 3‐month follow‐up.ConclusionThis study (predicted completion date: July 2021) is expected to provide valuable insights into the potential long‐term consequences of lockdown measures on people with dementia and their carers. Moreover, it will enable the identification of potential risk/protective factors for decline in mental health and cognition due to extensive changes in patients’ social environment. Findings from the SOLITUDE study may inform preventative and management strategies for decline in mental function targeting people with dementia, who may be the most affected by social isolation and loneliness.

The Effect of Hearing Aid Use on the Association Between Hearing Loss and Brain Structure in Older Adults.

Recent studies have shown an association between poorer hearing thresholds and smaller brain tissue volumes in older adults. Several underlying causal mechanisms have been opted, with a sensory deprivation hypothesis as one of the most prominent. If hearing deprivation would lead to less brain volume, hearing aids could be hypothesized to moderate this pathway by restoration of hearing. This study aims to investigate whether such a moderating effect of hearing aids exists. The authors conducted a cross-sectional study involving aging participants of the population-based Rotterdam Study. Hearing aid use was assessed by interview and hearing loss was quantified using pure-tone audiometry. Total brain volume, gray matter and white matter volume and white matter integrity [fractional anisotropy (FA) and mean diffusivity] were measured using magnetic resonance imaging. Only participants with a pure tone average at 1, 2, and 4 kHz (PTA1,2,4) of ≥35 dB HL were included. Associations of hearing loss with brain volume and global measures of white matter integrity were analyzed using linear regression, with hearing aid use and interaction between hearing aid use and PTA1,2,4 included as independent variables. Models were adjusted for age, sex, time between audiometry and magnetic resonance imaging, level of education, and cardiovascular risk factors. Out of 459 included participants with mean age (range) 70.4 (52 to 92) 41% were female. Distributions of age and sex among hearing aid users (n = 172) did not significantly differ from those without hearing aids. PTA1,2,4 was associated with lower FA, but not with a difference in total brain volume, gray matter volume, white matter volume, or mean diffusivity. Interaction between hearing aid use and PTA1,2,4 was not associated with FA or any of the other outcome measures. Additional analysis revealed that interaction between hearing aid use and age was associated with lower FA. We found no evidence for a moderating effect of hearing aids on the relationship between hearing loss and brain structure in a population of older adults. However, use of hearing aids did appear as an effect modifier in the association between age and white matter integrity. Future longitudinal research is needed to clarify these results.