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1.
Artigo em Inglês | MEDLINE | ID: mdl-32396611

RESUMO

We aimed to examine the relationship between APOE*4 carriage on cognitive decline, and whether these associations were moderated by sex, baseline age, ethnicity, and vascular risk factors. Participants were 19,225 individuals aged 54-103 years from 15 longitudinal cohort studies with a mean follow up duration ranging between 1.2 and 10.7 years. Two-step individual participant data (IPD) meta-analysis was used to pool results of study-wise analyses predicting memory and general cognitive decline from carriage of one or two APOE*4 alleles, and moderation of these associations by age, sex, vascular risk factors and ethnicity. Separate pooled estimates were calculated in both men and women who were younger (i.e., 62 years) and older (i.e., 80 years) at baseline. Results showed that APOE*4 carriage was related to faster general cognitive decline in women, and faster memory decline in men. A stronger dose-dependent effect was observed in older men, with faster general cognitive and memory decline in those carrying two versus one APOE*4 allele. Vascular risk factors were related to an increased effect of APOE*4 on memory decline in younger women, but a weaker effect of APOE*4 on general cognitive decline in older men. The relationship between APOE*4 carriage and memory decline was larger in older-aged Asians than Whites. In sum, APOE*4 is related to cognitive decline in men and women, although these effects are enhanced by age and carriage of two APOE*4 alleles in men, a higher numbers of vascular risk factors during the early stages of late adulthood in women, and Asian ethnicity.

2.
J Alzheimers Dis ; 2020 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-32417786

RESUMO

BACKGROUND: Alzheimer's disease (AD) begins decades before the onset of dementia. There is a need to investigate biomarkers of early AD for use in clinical trials and to facilitate early intervention. OBJECTIVE: We aimed to determine whether changes in hippocampal subfield volumes in healthy middle-aged adults were associated with risk of future dementia. METHODS: We included 150 participants from the PREVENT-Dementia cohort, which recruited subjects aged 40-59 with or without a family history of dementia (FHD; included here were 81 with FHD and 69 without). Hippocampal subfield volumes were segmented from high resolution T2-weighted 3T MRI images taken at baseline and 2-year follow-up. RESULTS: FHD and greater 20 year-risk of dementia due to cardiovascular risk factors were both associated with lower CA1 volume. FHD was also associated with a relative increase in combined CA3, CA4, and dentate gyrus volume between baseline and follow-up. CONCLUSION: CA1 atrophy may commence as early as middle-age in those with a high risk of future dementia, while increases in CA3, CA4, and dentate gyrus volume may be a response to early AD in the form of inflammation or neurogenesis.

3.
Neurobiol Aging ; 91: 36-44, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32311609

RESUMO

The hippocampus is one of the first regions to demonstrate atrophy during the prodromal stage of Alzheimer's disease. Volumetric analysis of its individual subfields could provide biomarkers with higher sensitivity than whole hippocampal volume during an earlier disease stage. We quantified the hippocampal subfields volume in a large cohort comprising healthy participants (aged 40-59) with dementia family history (FH) and controls (without FH), examined at 2 time points across 2 years. Subfield volumes were quantified using both a T1-weighted and a high-resolution T2 hippocampal magnetic resonance imaging acquisition with Freesurfer. The participants were stratified based on dementia FH, APOE genotype, and CAIDE (Cardiovascular Risk Factors, Aging and Dementia) risk score. Whole hippocampal volume did not differ between the groups. The volume of the molecular layer was lower in participants with an APOE ε4 genotype, but there were no differences between subjects with and without dementia FH or with an increasing CAIDE score. The molecular layer may be the first hippocampal region to demonstrate volumetric alterations in subjects at risk of dementia.

4.
J Alzheimers Dis ; 74(4): 1203-1210, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32144988

RESUMO

Alterations in Alzheimer's disease (AD) biomarkers have been observed decades before the onset of dementia. Cognitive dysfunction, while central to the clinical diagnosis of AD, has long been considered as a late-stage phenomenon. This assumption is currently challenged and signals on some cognitive tests are now being observed within the preclinical stage. As part of the European Prevention of Alzheimer's Dementia (EPAD) project, a battery of cognitive tests has been proposed (the EPAD Neuropsychological Examination, ENE) which is designed to detect cognitive changes in persons without clinical signs of AD but who are at high risk. Analysis of results from the 361 participants with complete measures and without dementia recruited into the EPAD Longitudinal Cohort Study showed that the majority have elevated biomarker levels, with significant associations between an episodic verbal memory task and tau, while amyloid-ß (Aß) was associated with a central executive task. These preliminary findings suggest that profiles of cognitive performance may be specific to a given biomarker, with a primarily hippocampal task being associated with higher levels of tau and a frontal executive task being associated with higher levels of Aß. While previous research has focused on the relationship between cognition and levels of Aß, our findings suggest that p-tau may potentially be a more significant correlate.

5.
Acta Ophthalmol ; 98(1): e63-e71, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31545560

RESUMO

PURPOSE: Ocular and brain microcirculation share embryological and histological similarities. The retinal vascular fractal dimension (FD) is a marker of retinal vascular complexity of the vascular tree. The purpose of this study was to explore the relationship between cerebral blood flow (CBF), retinal vascular FD and other retinal vascular markers. METHODS: Cross-sectional analysis comprising 26 individuals ≥65 years old from the Cognitive REServe and Clinical ENDOphenotype (CRESCENDO) cohort of relative healthy older adults. Retinal vascular FD was measured from fundus photographs by using the semi-automated Singapore Eye Vessel Assessment (SIVA) software. CBF was estimated using a 2D pulsed ASL MRI sequence. Associations between blood flow and retinal parameters were analysed using linear regression models adjusted for age and sex. RESULTS: Cerebral blood flow was positively associated with venular FD (R2  = 0.32, p = 0.03). This association was stronger in the anterior versus posterior brain territories (R2  = 0.35 [p = 0.001] versus R2  = 0.16 [p = 0.07], respectively). Global CBF was correlated with arteriolar branching angle (R2  = 0.23, p = 0.01) and tortuosity (R2  = 0.20, p = 0.02). Global CBF was not correlated with other SIVA parameters. CONCLUSIONS: Retinal venular complexity summarized by the FD was associated with cerebral blood flow as well as retinal arteriolar tortuosity and branching angle. Larger prospective clinical studies are needed to confirm these results.

6.
Depress Anxiety ; 37(2): 146-155, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31730745

RESUMO

BACKGROUND: Sex differences in psychiatric disorders are common and could involve sex steroids. Aromatase, the product of the CYP19A1 gene, is the key enzyme in the conversion of androgen to estrogen. Whether CYP19A1 variants could be associated with depression differently in men and women has not been examined. METHODS: This population-based study included 405 men and 602 women aged ≥65 years. A clinical level of depression (DEP) was defined as having a score ≥16 on the Center for Epidemiology Studies Depression scale or a diagnosis of current major depression based on the Mini-International Neuropsychiatric Interview and according to DSM-IV criteria. Seven single-nucleotide polymorphisms (SNPs) spanning the CYP19A1 gene were genotyped and circulating levels of estradiol and testosterone were determined. Multivariable analyses were adjusted for age, body mass index, ischemic pathologies, cognitive impairment, and anxiety. RESULTS: Five SNPs were associated with DEP in women specifically and this varied according to a history of major depression (p-values .01 to .0005). Three SNPs were associated with an increased risk of late-life DEP in women without a history of major depression, while two SNPs were associated with a decreased DEP risk in women with a history of major depression and were also associated with higher estradiol levels. CONCLUSIONS: Variants of the CYP19A1 gene appear to be susceptibility factors for late-life depression in a sex-specific manner. The polymorphisms decreasing the risk of recurrent depression in postmenopausal women also influence estradiol levels.

7.
J Neurol Neurosurg Psychiatry ; 91(2): 158-161, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31806724

RESUMO

BACKGROUND: Increased rates of brain atrophy on serial MRI are frequently used as a surrogate marker of disease progression in Alzheimer's disease and other dementias. However, the extent to which they are associated with future risk of dementia in asymptomatic subjects is not clear. In this study, we investigated the relationship between the Cardiovascular Risk Factors, Aging, and Dementia (CAIDE) risk score and longitudinal atrophy in middle-aged subjects. MATERIALS AND METHODS: A sample of 167 subjects (aged 40-59 at baseline) from the PREVENT-Dementia programme underwent MRI scans on two separate occasions (mean interval 735 days; SD 44 days). We measured longitudinal rates of brain atrophy using the FSL Siena toolbox. RESULTS: Annual percentage rates of brain volume and ventricular volume change were greater in those with a high (>6) vs low CAIDE score-absolute brain volume percentage loss 0.17% (CI 0.07 to 0.27) and absolute ventricular enlargement 1.78% (CI 1.14 to 2.92) higher in the at risk group. Atrophy rates did not differ between subjects with and without a parental history of dementia, but were significantly correlated with age. Using linear regression, with covariates of age, sex and education, CAIDE score >6 was the only significant predictor of whole brain atrophy rates (p=0.025) while age (p=0.009), sex (p=0.002) and CAIDE>6 (p=0.017) all predicted ventricular expansion rate. CONCLUSION: Our results show that progressive brain atrophy is associated with increased risk of future dementia in asymptomatic middle-aged subjects, two decades before dementia onset.

8.
J Alzheimers Dis ; 73(2): 645-655, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31839607

RESUMO

Brain-derived neurotrophic factor (BDNF) has been implicated in dementia. Preliminary evidence suggests that BDNF DNA methylation may be a diagnostic biomarker of dementia, but the potential pre-clinical utility remains unclear. Participants in the ESPRIT study were assessed for cognitive function and dementia (DSM-IV criteria) over 14 years. BDNF exon 1 promoter methylation was measured in blood at baseline (n = 769) and buccal samples during follow-up (n = 1062). Genotyping was carried out for several common BDNF SNPs, including Val66Met (rs6265) and APOE ɛ4. Multivariable logistic regression analyses determined the association between BDNF methylation and both prevalent and incident dementia. Adjustment for gender, age, education, APOEɛ4 genotype, body mass index, depression, and type 2 diabetes, as well as possible effect modification by gender and genetic variation were also investigated. Weak evidence of an association between lower blood methylation and dementia was observed at one of 11 sites investigated (Δ-0.5%, 95% CI:-0.9,-0.04, p = 0.03, p = 0.22 adjusted for multiple comparisons). Buccal methylation at two other sites was associated with 14-year incident dementia cases prior to adjustment for multiple comparisons only, and the effect sizes were small (Δ+0.3%, OR:1.57, SE:0.30, p = 0.02, p = 0.14 adjusted and Δ-1.5%, OR:0.85, SE:0.06, p = 0.03, p = 0.14 adjusted). Genetic variation in the BDNF gene did not modify these associations, and no gender-specific effects were observed. There was only a weak correlation between blood and buccal BDNF log-methylation at two sites (both r=-0.11). There was no strong evidence that blood or buccal BDNF exon 1 promoter DNA methylation is associated with prevalent or incident dementia, and reported associations would not remain after adjustment for multiple testing.

9.
Psychoneuroendocrinology ; 111: 104492, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31704635

RESUMO

BACKGROUND: Psychological stress is recognized as a major risk factor for a range of non-communicable diseases and possibly mortality. The extent to which the type and timing of stress exposure influences mortality, and potential differences between genders, remains unknown. OBJECTIVE: To examine the association between early-life and recent stressful experiences and mortality risk in later life, and to determine possible gender differences in these associations. METHOD: Data were obtained from 2152 French community-dwelling participants (aged ≥65). Questionnaires were used to evaluate recent stress, as well as retrospective reporting of childhood adversity. Mortality status was determined through death registries. Adjusted Cox proportional hazards models were used to determine the association between stress and 16-year mortality risk. RESULTS: Over a mean 12.9 years, 850 people died. Having a childhood home environment with very serious conflicts was associated with a 54% increased mortality risk (95%CI:1.21-1.96), and childhood abuse/maltreatment with a 34% increased risk (95% CI:1.05-1.70). For females, specific childhood events (serious illness HR:1.91, 95%CI:1.40-2.60; war/natural disaster HR:1.47, 95%CI:1.14-1.88) and the number of events (≥5 adverse events HR:1.91, 95%CI:1.25-2.32), also increased mortality risk. In terms of recent events, mortality risk increased by 66% (95%CI:1.39-2.00) in participants reporting a recent serious illness or physical trauma and by 86% for those reporting problems with the police/justice (95%CI:1.05-3.30). Among males specifically, mortality risk also increased with major financial problems (HR:1.92, 95%CI:1.14-3.21), and when they had a relative with a serious illness (HR:1.26, 95%CI:1.01-1.55). CONCLUSIONS: Stressful life experiences are associated with all-cause mortality however the associations varied between early-life adversities and recent stress, and were different across the genders. Among females, certain types of childhood adversity continue to predict mortality risk in later life, while in males specific recent stress significantly increased mortality risk.

10.
Artigo em Inglês | MEDLINE | ID: mdl-31833588

RESUMO

BACKGROUND: Observational studies indicate that approximately a third of dementia cases are attributable to modifiable cardiometabolic, physical and mental health, and social and lifestyle risk factors. There is evidence that intensive behaviour change interventions targeting these factors can reduce cognitive decline. [Figure: see text] METHODS AND ANALYSIS: We will design and test a low intensity, secondary dementia-prevention programme (Active Prevention in People at risk of dementia: Lifestyle, bEhaviour change and Technology to REducE cognitive and functional decline, "APPLE-Tree") to slow cognitive decline in people with subjective cognitive decline with or without objective cognitive impairment. We will embed our work within social science research to understand how dementia prevention is currently delivered and structured. We will carry out systematic reviews and around 50 qualitative interviews with stakeholders, using findings to coproduce the APPLE-Tree intervention. We plan a 10-session group intervention, involving personalised goal-setting, with individual sessions for those unable or unwilling to attend groups, delivered by psychology assistants who will be trained and supervised by clinical psychologists. The coproduction group (including public and patient involvement [PPI], academic and clinical/third-sector professional representatives) will use the Behaviour Change Wheel theoretical framework to develop it. We will recruit and randomly allocate 704 participants, 1:1 to the intervention: informational control group. This sample size is sufficient to detect a between-group difference at 2 years of 0.15 on the primary outcome (cognition: modified neuropsychological test battery; 90% power, 5% significance, effect size 0.25, SD 0.6). DISSEMINATION: We will work with Public Health England and third-sector partners to produce an effective national implementation approach, so that if our intervention works, it is used in practice.

11.
Transl Psychiatry ; 9(1): 291, 2019 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-31712553

RESUMO

Late-life depression, as a potential marker of pre-dementia, has seldom been explored by symptom dimension and sex, despite sexual dimorphic differences. This study aimed to examine whether specific depressive dimensions were associated with pre-Alzheimer's disease dementia (pre-AD), separately for women and men. Data were drawn from 5617 (58% women) community-dwellers aged 65+ recruited in 1999-2000 and followed at 2-year intervals for 12 years. We used Cox proportional hazard models to study associations between time-dependent Centre for Epidemiologic Studies-Depression Scale (CES-D) symptom dimensions (namely somatic, depressed, positive affect, and interpersonal challenge) and pre-AD, defined retrospectively from validated diagnoses established 3.5 (IQR: 3.2-4.0) years onwards. Analyses were performed according to overall depressive symptomatology (DS+: CES-D score ≥ 16) and antidepressant/anxiolytic medication use (AA). Results indicated that in DS+ women only, all four dimensions were significantly associated with pre-AD in the AA- group, in particular somatic item 'Mind' and depressed affect items 'Depressed' and 'Blues'. The most depression-specific dimension, depressed affect, was also significantly associated with pre-AD in the DS- AA- women (HR:1.28, 95%CI: 1.12;1.47). In both sexes, in the DS- groups somatic affect was the most robust pre-AD marker, irrespective of treatment (women: HR = 1.22, 95%CI: 1.08;1.38; men: HR = 1.30, 95%CI: 1.14;1.48). Our findings highlight sex-specific associations between depressive symptom dimensions and pre-AD, modulated by depressive symptomatology and treatment. Assessment of specific symptom dimensions taking into account overall symptomatology and treatment could help identify and target high-risk AD-dementia profiles for interventions.

12.
PLoS Med ; 16(7): e1002853, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31335910

RESUMO

BACKGROUND: With no effective treatments for cognitive decline or dementia, improving the evidence base for modifiable risk factors is a research priority. This study investigated associations between risk factors and late-life cognitive decline on a global scale, including comparisons between ethno-regional groups. METHODS AND FINDINGS: We harmonized longitudinal data from 20 population-based cohorts from 15 countries over 5 continents, including 48,522 individuals (58.4% women) aged 54-105 (mean = 72.7) years and without dementia at baseline. Studies had 2-15 years of follow-up. The risk factors investigated were age, sex, education, alcohol consumption, anxiety, apolipoprotein E ε4 allele (APOE*4) status, atrial fibrillation, blood pressure and pulse pressure, body mass index, cardiovascular disease, depression, diabetes, self-rated health, high cholesterol, hypertension, peripheral vascular disease, physical activity, smoking, and history of stroke. Associations with risk factors were determined for a global cognitive composite outcome (memory, language, processing speed, and executive functioning tests) and Mini-Mental State Examination score. Individual participant data meta-analyses of multivariable linear mixed model results pooled across cohorts revealed that for at least 1 cognitive outcome, age (B = -0.1, SE = 0.01), APOE*4 carriage (B = -0.31, SE = 0.11), depression (B = -0.11, SE = 0.06), diabetes (B = -0.23, SE = 0.10), current smoking (B = -0.20, SE = 0.08), and history of stroke (B = -0.22, SE = 0.09) were independently associated with poorer cognitive performance (p < 0.05 for all), and higher levels of education (B = 0.12, SE = 0.02) and vigorous physical activity (B = 0.17, SE = 0.06) were associated with better performance (p < 0.01 for both). Age (B = -0.07, SE = 0.01), APOE*4 carriage (B = -0.41, SE = 0.18), and diabetes (B = -0.18, SE = 0.10) were independently associated with faster cognitive decline (p < 0.05 for all). Different effects between Asian people and white people included stronger associations for Asian people between ever smoking and poorer cognition (group by risk factor interaction: B = -0.24, SE = 0.12), and between diabetes and cognitive decline (B = -0.66, SE = 0.27; p < 0.05 for both). Limitations of our study include a loss or distortion of risk factor data with harmonization, and not investigating factors at midlife. CONCLUSIONS: These results suggest that education, smoking, physical activity, diabetes, and stroke are all modifiable factors associated with cognitive decline. If these factors are determined to be causal, controlling them could minimize worldwide levels of cognitive decline. However, any global prevention strategy may need to consider ethno-regional differences.


Assuntos
Cognição , Disfunção Cognitiva/etnologia , Grupos Étnicos/psicologia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Disfunção Cognitiva/diagnóstico , Disfunção Cognitiva/psicologia , Comorbidade , Diabetes Mellitus/etnologia , Exercício Físico , Feminino , Educação em Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Medição de Risco , Fatores de Risco , Fumar/efeitos adversos , Fumar/etnologia , Acidente Vascular Cerebral/etnologia
14.
Aging Dis ; 10(2): 463-469, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31011488

RESUMO

Chronic systemic low-grade inflammation is associated with aging, but little is known on whether age-related inflammation affects brain structure, particularly white matter. The current study tested the hypothesis that in older adults without dementia, higher serum levels of high-sensitivity C-reactive protein (hs-CRP) are associated with reduced corpus callosum (CC) areas. French community-dwelling subjects (ESPRIT study) aged 65 and older (N=101) underwent hs-CRP testing and structural magnetic resonance imaging (MRI). Multiple linear regression models were carried out. In the unadjusted model, higher hs-CRP level was significantly associated with smaller anterior, mid, and total midsagittal CC areas, but not with the posterior CC area. These associations were independent of demographic characteristics and intracranial volume. After adjustment for body mass index, diabetes, inflammation-related chronic pathologies and white matter lesions (WML), only the associations between hs-CRP level and smaller anterior and total midsagittal CC areas were still significant, although weaker. These findings suggest that low-grade inflammation is associated with CC structural integrity alterations in older adults independently of physical or neuropsychiatric pathologies.

15.
Stress ; 22(1): 162-168, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30298755

RESUMO

A recent study reported for the first time, that DNA methylation of the KITLG gene mediates the association between childhood trauma and cortisol stress reactivity. Our study aimed to provide the first independent replication of these findings. ESPRIT is a prospective study of community-dwelling participants (age ≥ 65), randomly selected from the electoral rolls of the Montpellier district, in France. Clinical depression was assessed using the Mini-International Neuropsychiatric Interview (MINI, French version 5.00), and the Centre for Epidemiological Studies Depression Scale (CES-D). Experiences of childhood adversity were ascertained via a 25-item questionnaire. Morning, evening, and diurnal salivary cortisol was measured under basal and stress conditions and determined using direct radioimmunoassay analysis. DNA methylation of the KITLG gene was quantified in whole blood using the SEQUENOM MassARRAY EpiTYPER platform. A significant negative association was observed between KITLG DNA methylation and both morning cortisol (ß = -1.846 ± 0.666, p = .007) and diurnal cortisol (area under curve [AUC]) (ß = -19.429 ± 8.868, p = .031) under a stress condition. However, only the former association was significant after correcting for multiple testing. Further, this association remained after adjusting for age, sex, and depression status. No significant association was observed between childhood trauma and KITLG DNA methylation in this older population. This study provides support for an association between KITLG methylation and stress cortisol levels, suggesting that DNA methylation of this gene may play a role in the longer term regulation of the stress system. Lay summary The significant negative association between KITLG DNA methylation and morning cortisol, measured under a stressful condition, suggests that individuals with higher KITLG methylation will secrete lower levels of cortisol whilst under stress.


Assuntos
Metilação de DNA , Hidrocortisona/metabolismo , Fator de Células-Tronco/genética , Estresse Psicológico/genética , Criança , Feminino , Humanos , Sistema Hipotálamo-Hipofisário/metabolismo , Masculino , Sistema Hipófise-Suprarrenal/metabolismo , Estudos Prospectivos , Saliva/química , Saliva/metabolismo , Estresse Psicológico/metabolismo , Inquéritos e Questionários
16.
J Psychiatry Neurosci ; 44(1): 45-53, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30565905

RESUMO

Background: There is evidence of structural brain alterations in major depressive disorder (MDD), but little is known about how these alterations might be affected by age at onset or genetic vulnerability. This study examines whether lifetime episodes of MDD are associated with specific alterations in grey-matter volume, and whether those alterations vary according to sex or serotonin transporter-linked promoter region (5-HTTLPR) genotype (LL, SL or SS). Methods: We used structural MRI to acquire anatomic scans from 610 community-dwelling participants. We derived quantitative regional estimates of grey-matter volume in 16 subregions using FreeSurfer software. We diagnosed MDD according to DSM-IV criteria. We adjusted analyses for age, sex, total brain volume, education level, head injury and comorbidities. Results: Lifetime MDD was associated with a smaller insula, thalamus, ventral diencephalon, pallidum and nucleus accumbens and with a larger pericalcarine region in both men and women. These associations remained after adjustment for false discovery rate. Lifetime MDD was also associated with a smaller caudate nucleus and amygdala in men and with a larger rostral anterior cingulate cortex in women. Late-onset first episodes of MDD (after age 50 years) were associated with a larger rostral anterior cingulate cortex and lingual and pericalcarine regions; early-onset MDD was associated with a smaller ventral diencephalon and nucleus accumbens. Some associations differed according to 5-HTTLPR genotype: the thalamus was smaller in participants with MDD and the LL genotype; pericalcarine and lingual volumes were higher in those with the SL genotype. Limitations: This study was limited by its cross-sectional design. Conclusion: Major depressive disorder was associated with persistent volume reductions in the deep nuclei and insula and with enlargements in visual cortex subregions; alterations varied according to age of onset and genotype.

17.
BMC Psychiatry ; 18(1): 282, 2018 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-30180828

RESUMO

BACKGROUND: Disrupted serotonergic signaling is often a feature of depression and the role of the serotonin transporter gene (SLC6A4), responsible for serotonin re-uptake, has received much attention in this regard. Most studies have focused on the polymorphic 5-HTTLPR upstream repeat, or DNA methylation at the promoter CpG island. Few studies have explored the influence of genetic variation across the gene on DNA methylation, and their combined association with depression risk. The aim of this study was to determine whether genetic variation in the SLC6A4 gene influences promoter DNA methylation, and whether these are associated with depression status. METHOD: The ESPRIT study involves a community-based population of older individuals (> 65 years of age). Major depressive disorder (MDD) was diagnosed according to DSM-IV (American Psychiatric Association, 1994) criteria, and severe depressive symptoms assessed by the Centre for Epidemiological Studies Depression (CES-D) Scale. Sequenom MassARRAY was used to measure SLC6A4 methylation status (n = 302). RESULTS: Nominally significant associations were observed between SLC6A4 genetic variants (5-HTTLPR, rs140700, rs4251417, rs6354, rs25528, rs25531) and DNA methylation at several CpG sites. In multivariate regression, DNA methylation was associated with depression status, but only in the presence of specific genotypes. In individuals homozygous for the short 5-HTTLPR and 5-HTTLPR/r25531 alleles, lower methylation at two CpGs was associated with depression (ß = - 0.44 to ß = - 0.31; p = 0.001 to p = 0.038). CONCLUSION: We present evidence for genotype-dependent associations between SLC6A4 methylation and depression. Genetic variants may also play a role in influencing promoter methylation levels and its association with depression.


Assuntos
Metilação de DNA/genética , Transtorno Depressivo Maior/genética , Estudos de Associação Genética/métodos , Genótipo , Proteínas da Membrana Plasmática de Transporte de Serotonina/genética , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Transtorno Depressivo Maior/diagnóstico , Transtorno Depressivo Maior/psicologia , Feminino , Humanos , Masculino , Regiões Promotoras Genéticas/genética , Distribuição Aleatória , Autorrelato
18.
J Alzheimers Dis ; 65(3): 885-896, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30103333

RESUMO

Impairments in spatial processing due to hippocampal degeneration have been observed in the years immediately preceding the diagnosis of Alzheimer's disease (AD) dementia. The demonstration of changes in spatial processing in preceding decades would provide a cognitive marker for pre-clinical AD and an outcome measure for early intervention trials. The present study examined allocentric and egocentric spatial processing in relation to future dementia risk in a middle-aged cohort. The CAIDE Dementia Risk Score (DRS) was calculated for 188 persons aged 40 to 59, of whom 94 had a parent with dementia. Participants underwent the Four Mountains Test (4MT) of allocentric spatial processing, the Virtual Reality Supermarket Trolley Task (VRSTT) of egocentric spatial processing, and 3T MRI scans. A significant negative association was found between the DRS and 4MT (Spearman correlation - 0.26, p = 0.0006), but not with the VRSTT. The 4MT was also found to be a better predictor of risk than tests of episodic memory, verbal fluency, or executive functioning. The results suggest that allocentric rather than egocentric processing may be a potential indicator of risk for late-onset AD, consistent with the hypothesis that the earliest cognitive changes in AD are driven by tau-related degeneration in the medial temporal lobe rather than amyloid-only deposition in the medial parietal lobe.


Assuntos
Doença de Alzheimer/psicologia , Percepção Espacial , Navegação Espacial , Idade de Início , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/epidemiologia , Doença de Alzheimer/genética , Encéfalo/diagnóstico por imagem , Estudos Transversais , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Pais , Estudos Prospectivos , Fatores de Risco , Autoimagem
19.
Alzheimers Dement ; 14(6): 837-842, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29604264

RESUMO

INTRODUCTION: It is a challenge to find participants for Alzheimer's disease (AD) prevention trials within a short period of time. The European Prevention of Alzheimer's Dementia Registry (EPAD) aims to facilitate recruitment by preselecting subjects from ongoing cohort studies. This article introduces this novel approach. METHODS: A virtual registry, with access to risk factors and biomarkers for AD through minimal data sets of ongoing cohort studies, was set up. RESULTS: To date, ten cohorts have been included in the EPAD. Around 2500 participants have been selected, using variables associated with the risk for AD. Of these, 15% were already recruited in the EPAD longitudinal cohort study, which serves as a trial readiness cohort. DISCUSSION: This study demonstrates that a virtual registry can be used for the preselection of participants for AD studies.


Assuntos
Doença de Alzheimer/prevenção & controle , Ensaios Clínicos como Assunto , Seleção de Pacientes , Sistema de Registros , Idoso , Idoso de 80 Anos ou mais , Biomarcadores , Europa (Continente) , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Sintomas Prodrômicos , Fatores de Risco
20.
J Psychiatr Res ; 102: 159-167, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29665490

RESUMO

BACKGROUND: Structural neuroimaging studies revealed a consistent pattern of volumetric reductions in both hippocampus (HC) and anterior cingulate cortex (ACC) of individuals with major depressive episode(s) (MDE). This study investigated HC and ACC volume differences in currently depressed individuals (n = 150), individuals with a past lifetime MDE history (n = 79) and healthy controls (n = 287). METHODS: Non-demented individuals were recruited from a cohort of community-dwelling older adults (ESPRIT study). T1-weighted magnetic resonance images and FreeSurfer Software (automated method) were used. Concerning HC, a manual method of measurement dividing HC into head, body, and tail was also used. General Linear Model was applied adjusting for covariates. RESULTS: Current depression was associated with lower left posterior HC volume, using manual measurement, in comparison to healthy status. However, when we slightly changed sub-group inclusion criteria, results did not survive to correction for multiple comparisons. CONCLUSIONS: The finding of lower left posterior HC volume in currently depressed individuals but not in those with a past MDE compared to healthy controls could be related to brain neuroplasticity. Additionally, our results may suggest manual measures to be more sensitive than automated methods.


Assuntos
Transtorno Depressivo Maior/diagnóstico por imagem , Hipocampo/diagnóstico por imagem , Hipocampo/patologia , Idoso , Idoso de 80 Anos ou mais , Transtorno Depressivo Maior/complicações , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Modelos Lineares , Imagem por Ressonância Magnética , Masculino , Síndrome Metabólica/diagnóstico por imagem , Síndrome Metabólica/etiologia , Estudos Prospectivos , Escalas de Graduação Psiquiátrica , Reprodutibilidade dos Testes
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