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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 Clin Med ; 9(5)2020 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-32384818

RESUMO

The association between anxiety and vascular dementia (VaD) is unclear. We aimed to reliably estimate the association between anxiety and VaD risk using meta-analysis to pool new results from a large community-based cohort (Zaragoza Dementia and Depression (ZARADEMP) study) and results from previous studies. ZARADEMP participants (n = 4057) free of dementia were followed up on for up to 12 years. Cases and subcases of anxiety were determined at baseline. A panel of four psychiatrists diagnosed incident cases of VaD by consensus. We searched for similar studies published up to October 2019 using PubMed and Web of Science. Observational studies reporting associations between anxiety and VaD risk, and adjusting at least for age, were selected. Odds ratios (ORs) from each study were combined using fixed-effects models. In the ZARADEMP study, the risk of VaD was 1.41 times higher among individuals with anxiety (95% CI: 0.75-2.68) compared with non-cases (p = 0.288). Pooling this result with results from two previous studies yielded an OR of 1.65 (95% CI: 1.07-2.53; p = 0.022). These findings indicate that anxiety is associated with an increased risk of VaD. Taking into account that anxiety is commonly observed in the elderly, treating and preventing it might reduce the prevalence and incidence of VaD. However, whether anxiety is a cause of a prodrome of VaD is still unknown, and future research is needed to clarify this.

3.
Stroke ; : STROKEAHA119028428, 2020 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-32404039

RESUMO

Background and Purpose- Type 2 diabetes mellitus (T2D) is associated with cognitive impairment and an increased risk of dementia, but the association between prediabetes and cognitive impairment is less clear, particularly in a setting of major cerebrovascular events. This article examines the impact of impaired fasting glucose and T2D on cognitive performance in a stroke population. Methods- Seven international observational studies from the STROKOG (Stroke and Cognition) consortium (n=1601; mean age, 66.0 years; 70% Asian, 26% white, and 2.6% African American) were included. Fasting glucose level (FGL) during hospitalization was used to define 3 groups, T2D (FGL ≥7.0 mmol/L), impaired fasting glucose (FGL 6.1-6.9 mmol/L), and normal (FGL <6.1 mmol/L), and a history of diabetes mellitus and the use of a diabetes mellitus medication were also used to support a diagnosis of T2D. Domain and global cognition Z scores were derived from standardized neuropsychological test scores. The cross-sectional association between glucose status and cognitive performance at 3 to 6 months poststroke was examined using linear mixed models, adjusting for age, sex, education, stroke type, ethnicity, and vascular risk factors. Results- Patients with T2D had significantly poorer performance in global cognition (SD, -0.59 [95% CI, -0.82 to -0.36]; P<0.001) and in all domains compared with patients with normal FGL. There was no significant difference between impaired fasting glucose patients and those with normal FGL in global cognition (SD, -0.10 [95% CI, -0.45 to 0.24]; P=0.55) or in any cognitive domain. Conclusions- Diabetes mellitus, but not prediabetes, is associated with poorer cognitive performance in patients 3 to 6 months after stroke.

4.
Sports Med ; 50(2): 403-413, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31529300

RESUMO

BACKGROUND: Besides physical activity as a target for dementia prevention, sedentary behaviour is hypothesized to be a potential target in its own right. The rising number of persons with dementia and lack of any effective treatment highlight the urgency to better understand these modifiable risk factors. Therefore, we aimed to investigate whether higher levels of sedentary behaviour are associated with reduced global cognitive functioning and slower cognitive decline in older persons without dementia. METHODS: We used five population cohorts from Greece, Australia, USA, Japan, and Singapore (HELIAD, PATH, SALSA, SGS, and SLAS2) from the Cohort Studies of Memory in an International Consortium. In a coordinated analysis, we assessed the relationship between sedentary behaviour and global cognitive function with the use of linear mixed growth model analysis (mean follow-up range of 2.0-8.1 years). RESULTS: Baseline datasets combined 10,450 older adults without dementia with a mean age range between cohorts of 66.7-75.1 years. After adjusting for multiple covariates, no cross-sectional association between sedentary behaviour and cognition was found in four studies. One association was detected where more sedentary behaviour was cross-sectionally linked to higher cognition levels (SLAS2, B = 0.118 (0.075; 0.160), P < 0.001). Longitudinally, there were no associations between baseline sedentary behaviour and cognitive decline (P > 0.05). CONCLUSIONS: Overall, these results do not suggest an association between total sedentary time and lower global cognition in older persons without dementia at baseline or over time. We hypothesize that specific types of sedentary behaviour may differentially influence cognition which should be investigated further. For now, it is, however, too early to establish undifferentiated sedentary time as a potential effective target for minimizing cognitive decline in older adults without dementia.

5.
Aging Clin Exp Res ; 32(2): 215-221, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31755024

RESUMO

BACKGROUND AND AIMS: Among older adults, olfactory dysfunction is associated with cognitive impairment, lower quality of life, and increased mortality. While age is a risk factor for olfactory dysfunction, other risk factors are less well understood, and may vary between ethno-regional groups. This study investigated how associations between odour identification (OI) and various risk factors, as well as cognition and language ability, differed or were similar in two distinct ethno-regional groups of older adults. METHODS: This cross-sectional study used data from two cohorts: 470 Indonesians (aged 67.4 ± 7.4 years) and 819 white Australians (aged 78.7 ± 4.8 years). Univariate and multivariate analyses explored whether OI test scores were associated with age, sex, education, cholesterol levels, apolipoprotein E ε4 status, smoking, diabetes, hypertension and depression scale scores, or with Mini-Mental State Examination (MMSE) and language test performance. RESULTS: Univariate analyses identified some factors associated with OI scores in both Indonesians and white Australians, including older age and smoking with lower scores, and MMSE and language test performance with higher scores. Multivariate analyses yielded different and mutually exclusive patterns of associations in the two ethno-regional groups, with language test scores significantly associated with higher OI scores in Indonesians, and age, being male, smoking, having diabetes and higher depression scale scores significantly associated with lower OI scores in white Australians. CONCLUSION: Ethno-regional differences may need consideration in the attempt to fully understand associations between OI and negative outcomes like dementia and mortality, and interventions for olfactory dysfunction might need to be tailored to specific ethno-regional groups. However, the difference in mean age between cohorts is a limitation of this study, and future studies should aim to compare populations with similar age distributions.

6.
Neurology ; 93(24): e2257-e2271, 2019 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-31712368

RESUMO

OBJECTIVE: To address the variability in prevalence estimates and inconsistencies in potential risk factors for poststroke cognitive impairment (PSCI) using a standardized approach and individual participant data (IPD) from international cohorts in the Stroke and Cognition Consortium (STROKOG) consortium. METHODS: We harmonized data from 13 studies based in 8 countries. Neuropsychological test scores 2 to 6 months after stroke or TIA and appropriate normative data were used to calculate standardized cognitive domain scores. Domain-specific impairment was based on percentile cutoffs from normative groups, and associations between domain scores and risk factors were examined with 1-stage IPD meta-analysis. RESULTS: In a combined sample of 3,146 participants admitted to hospital for stroke (97%) or TIA (3%), 44% were impaired in global cognition and 30% to 35% were impaired in individual domains 2 to 6 months after the index event. Diabetes mellitus and a history of stroke were strongly associated with poorer cognitive function after covariate adjustments; hypertension, smoking, and atrial fibrillation had weaker domain-specific associations. While there were no significant differences in domain impairment among ethnoracial groups, some interethnic differences were found in the effects of risk factors on cognition. CONCLUSIONS: This study confirms the high prevalence of PSCI in diverse populations, highlights common risk factors, in particular diabetes mellitus, and points to ethnoracial differences that warrant attention in the development of prevention strategies.


Assuntos
Disfunção Cognitiva/epidemiologia , Disfunção Cognitiva/etiologia , Acidente Vascular Cerebral/complicações , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco
7.
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
8.
Maturitas ; 119: 14-20, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30502746

RESUMO

OBJECTIVES: Anxiety is postulated to be modifiable risk factor for dementia. Our primary aim was to conduct a meta-analysis of community-based cohort studies that investigated the association between anxiety and dementia. DESIGN: We identified relevant, high-quality papers published up to January 2018 by searching PubMed and Web of Science. Prospective cohort studies reporting relative risks (RRs) for the association between anxiety and dementia, adjusted at least for age, were considered eligible. Study-specific RRs were combined using a random-effects model. RESULTS: Six prospective cohorts (reported in 5 studies), with a total of 10,394 participants, were included in the meta-analysis. The pooled RR of 1.29 (95% CI: 1.01-1.66) indicated a significant association between anxiety and dementia. CONCLUSION: Anxiety significantly increases the risk of dementia. However, further research is needed to determine the extent to which anxiety is a cause of dementia rather than a prodrome or marker.


Assuntos
Ansiedade/epidemiologia , Demência/epidemiologia , Humanos , Estudos Prospectivos , Fatores de Risco
9.
Int Psychogeriatr ; : 1-10, 2018 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-30355384

RESUMO

ABSTRACTObjectives:To investigate whether amnestic mild cognitive impairment (aMCI) identified with visual memory tests conveys an increased risk of Alzheimer's disease (risk-AD) and if the risk-AD differs from that associated with aMCI based on verbal memory tests. PARTICIPANTS: 4,771 participants aged 70.76 (SD = 6.74, 45.4% females) from five community-based studies, each a member of the international COSMIC consortium and from a different country, were classified as having normal cognition (NC) or one of visual, verbal, or combined (visual and verbal) aMCI using international criteria and followed for an average of 2.48 years. Hazard ratios (HR) and individual patient data (IPD) meta-analysis analyzed the risk-AD with age, sex, education, single/multiple domain aMCI, and Mini-Mental State Examination (MMSE) scores as covariates. RESULTS: All aMCI groups (n = 760) had a greater risk-AD than NC (n = 4,011; HR range = 3.66 - 9.25). The risk-AD was not different between visual (n = 208, 17 converters) and verbal aMCI (n = 449, 29 converters, HR = 1.70, 95%CI: 0.88, 3.27, p = 0.111). Combined aMCI (n = 103, 12 converters, HR = 2.34, 95%CI: 1.13, 4.84, p = 0.023) had a higher risk-AD than verbal aMCI. Age and MMSE scores were related to the risk-AD. The IPD meta-analyses replicated these results, though with slightly lower HR estimates (HR range = 3.68, 7.43) for aMCI vs. NC. CONCLUSIONS: Although verbal aMCI was most common, a significant proportion of participants had visual-only or combined visual and verbal aMCI. Compared with verbal aMCI, the risk-AD was the same for visual aMCI and higher for combined aMCI. Our results highlight the importance of including both verbal and visual memory tests in neuropsychological assessments to more reliably identify aMCI.

10.
Neuroimage Clin ; 20: 260-266, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30094174

RESUMO

Evidence suggests that disruptions of the posteromedial cortex (PMC) and posteromedial corticothalamic connectivity contribute to disorders of consciousness (DOCs). While most previous studies treated the PMC as a whole, this structure is functionally heterogeneous. The present study investigated whether particular subdivisions of the PMC are specifically associated with DOCs. Participants were DOC patients, 21 vegetative state/unresponsive wakefulness syndrome (VS/UWS), 12 minimally conscious state (MCS), and 29 healthy controls. Individual PMC and thalamus were divided into distinct subdivisions by their fiber tractograpy to each other and default mode regions, and white matter integrity and brain activity between/within subdivisions were assessed. The thalamus was represented mainly in the dorsal and posterior portions of the PMC, and the white matter tracts connecting these subdivisions to the thalamus had less integrity in VS/UWS patients than in MCS patients and healthy controls. In addition, these tracts had less integrity in DOC patients who did not recover after 12 months than in patients who did. The structural substrates were validated by resting state fMRI finding impaired functional activity within these PMC subdivisions. This study is the first to show that tracts from dorsal and posterior subdivisions of the PMC to the thalamus contribute to DOCs.


Assuntos
Córtex Cerebral/diagnóstico por imagem , Transtornos da Consciência/diagnóstico por imagem , Imagem por Ressonância Magnética/métodos , Rede Nervosa/diagnóstico por imagem , Adulto , Transtornos da Consciência/psicologia , Imagem de Tensor de Difusão/métodos , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Lobo Parietal/diagnóstico por imagem
11.
J Am Med Dir Assoc ; 19(11): 981-988.e7, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30056008

RESUMO

OBJECTIVES: Slow gait speed may be associated with premature mortality, cardiovascular disease (CVD), and cancer, although a comprehensive meta-analysis is lacking. In this systematic review and meta-analysis, we explored potential associations between gait speed and mortality, incident CVD, and cancer. DESIGN: A systematic search in major databases was undertaken from inception until March 15, 2018 for prospective cohort studies reporting data on gait speed and mortality, incident CVD, and cancer. SETTING AND PARTICIPANTS: All available. MEASURES: The adjusted hazard ratios (HRs) and 95% confidence intervals (CIs), based on the model with the maximum number of covariates for each study between gait speed (categorized as decrease in 0.1 m/s) and mortality, incident CVD, and cancer, were meta-analyzed with a random effects model. RESULTS: Among 7026 articles, 44 articles corresponding to 48 independent cohorts were eligible. The studies followed up on a total of 101,945 participants (mean age 72.2 years; 55% women) for a median of 5.4 years. After adjusting for a median of 9 potential confounders and the presence of publication bias, each reduction of 0.1 m/s in gait speed was associated with a 12% increased risk of earlier mortality (45 studies; HR = 1.12, 95% CI: 1.09-1.14; I2 = 90%) and 8% increased risk of CVD (13 studies; HR = 1.08, 95% CI: 1.03-1.13; I2 = 81%), but no relationship with cancer was observed (HR = 1.00, 95% CI: 0.97-1.04; I2 = 15%). CONCLUSION/IMPLICATIONS: Slow gait speed may be a predictor of mortality and CVD in older adults. Because gait speed is a quick and inexpensive measure to obtain, our study suggests that it should be routinely used and may help identify people at risk of premature mortality and CVD.


Assuntos
Doenças Cardiovasculares/fisiopatologia , Mortalidade , Neoplasias/fisiopatologia , Medição de Risco , Velocidade de Caminhada/fisiologia , Humanos
12.
Neurology ; 91(7): e643-e651, 2018 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-30021919

RESUMO

OBJECTIVE: To investigate the effects of completed pregnancy with childbirth and incomplete pregnancy without childbirth on the late-life cognition and the risk of Alzheimer disease (AD) in women. METHODS: Using the pooled data of 3,549 women provided by 2 population-based cohort studies, we conducted logistic regression analyses to examine retrospectively the associations of completed and incomplete pregnancy with the risks of mild cognitive impairment and AD. For women without dementia, we also conducted analyses of covariance to examine the associations of completed and incomplete pregnancy with Mini-Mental State Examination (MMSE) score. RESULTS: Grand multiparous women who experienced ≥5 completed pregnancies showed an ≈1.7-fold higher risk of AD than those who experienced 1 to 4 completed pregnancies (odds ratio [OR] 1.68, 95% confidence interval [CI] 1.04-2.72), while those who had incomplete pregnancies showed half the level of AD risk compared with those who never experienced an incomplete pregnancy (OR 0.43, 95% CI 0.24-0.76 for 1 incomplete pregnancy; OR 0.56, 95% CI 0.34-0.92 for ≥2 incomplete pregnancies). In women without dementia, the grand multiparous had worse MMSE scores than those with 1 to 4 completed pregnancies (p < 0.001), while those who experienced ≥1 incomplete pregnancies had better MMSE scores than those who never experienced an incomplete pregnancy (p = 0.008). CONCLUSIONS: Grand multiparity was associated with high risk of AD, while incomplete pregnancy was associated with low risk of AD in late life.


Assuntos
Doença de Alzheimer/epidemiologia , Complicações na Gravidez/epidemiologia , História Reprodutiva , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/complicações , Transtornos Cognitivos/etiologia , Estudos de Coortes , Planejamento em Saúde Comunitária , Feminino , Humanos , Cooperação Internacional , Pessoa de Meia-Idade , Gravidez , Escalas de Graduação Psiquiátrica , República da Coreia/epidemiologia
13.
J Am Geriatr Soc ; 66(7): 1360-1366, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29745971

RESUMO

OBJECTIVES: To investigate the implications of obtaining one or more low scores on a battery of cognitive tests on diagnosing mild cognitive impairment (MCI). DESIGN: Observational longitudinal study. SETTING: Alzheimer's Disease Neuroimaging Initiative. PARTICIPANTS: Normal controls (NC, n = 280) and participants with MCI (n = 415) according to Petersen criteria were reclassified using the Jak/Bondi criteria and number of impaired tests (NIT) criteria. MEASUREMENTS: Diagnostic statistics and hazard ratios of progression to Alzheimer's disease (AD) were compared according to diagnostic criteria. RESULTS: The NIT criteria were a better predictor of progression to AD than the Petersen or Jak/Bondi criteria, with optimal sensitivity, specificity, and positive and negative predictive value. CONCLUSION: Considering normal variability in cognitive test performance when diagnosing MCI may help identify individuals at greatest risk of progression to AD with greater certainty.


Assuntos
Disfunção Cognitiva/diagnóstico , Avaliação Geriátrica/métodos , Testes Neuropsicológicos/normas , Idoso , Doença de Alzheimer/diagnóstico , Estudos de Casos e Controles , Progressão da Doença , Função Executiva , Feminino , Humanos , Estudos Longitudinais , Masculino , Entrevista Psiquiátrica Padronizada/normas , Valores de Referência
14.
PLoS Med ; 14(3): e1002261, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28323832

RESUMO

BACKGROUND: The prevalence of dementia varies around the world, potentially contributed to by international differences in rates of age-related cognitive decline. Our primary goal was to investigate how rates of age-related decline in cognitive test performance varied among international cohort studies of cognitive aging. We also determined the extent to which sex, educational attainment, and apolipoprotein E ε4 allele (APOE*4) carrier status were associated with decline. METHODS AND FINDINGS: We harmonized longitudinal data for 14 cohorts from 12 countries (Australia, Brazil, France, Greece, Hong Kong, Italy, Japan, Singapore, Spain, South Korea, United Kingdom, United States), for a total of 42,170 individuals aged 54-105 y (42% male), including 3.3% with dementia at baseline. The studies began between 1989 and 2011, with all but three ongoing, and each had 2-16 assessment waves (median = 3) and a follow-up duration of 2-15 y. We analyzed standardized Mini-Mental State Examination (MMSE) and memory, processing speed, language, and executive functioning test scores using linear mixed models, adjusted for sex and education, and meta-analytic techniques. Performance on all cognitive measures declined with age, with the most rapid rate of change pooled across cohorts a moderate -0.26 standard deviations per decade (SD/decade) (95% confidence interval [CI] [-0.35, -0.16], p < 0.001) for processing speed. Rates of decline accelerated slightly with age, with executive functioning showing the largest additional rate of decline with every further decade of age (-0.07 SD/decade, 95% CI [-0.10, -0.03], p = 0.002). There was a considerable degree of heterogeneity in the associations across cohorts, including a slightly faster decline (p = 0.021) on the MMSE for Asians (-0.20 SD/decade, 95% CI [-0.28, -0.12], p < 0.001) than for whites (-0.09 SD/decade, 95% CI [-0.16, -0.02], p = 0.009). Males declined on the MMSE at a slightly slower rate than females (difference = 0.023 SD/decade, 95% CI [0.011, 0.035], p < 0.001), and every additional year of education was associated with a rate of decline slightly slower for the MMSE (0.004 SD/decade less, 95% CI [0.002, 0.006], p = 0.001), but slightly faster for language (-0.007 SD/decade more, 95% CI [-0.011, -0.003], p = 0.001). APOE*4 carriers declined slightly more rapidly than non-carriers on most cognitive measures, with processing speed showing the greatest difference (-0.08 SD/decade, 95% CI [-0.15, -0.01], p = 0.019). The same overall pattern of results was found when analyses were repeated with baseline dementia cases excluded. We used only one test to represent cognitive domains, and though a prototypical one, we nevertheless urge caution in generalizing the results to domains rather than viewing them as test-specific associations. This study lacked cohorts from Africa, India, and mainland China. CONCLUSIONS: Cognitive performance declined with age, and more rapidly with increasing age, across samples from diverse ethnocultural groups and geographical regions. Associations varied across cohorts, suggesting that different rates of cognitive decline might contribute to the global variation in dementia prevalence. However, the many similarities and consistent associations with education and APOE genotype indicate a need to explore how international differences in associations with other risk factors such as genetics, cardiovascular health, and lifestyle are involved. Future studies should attempt to use multiple tests for each cognitive domain and feature populations from ethnocultural groups and geographical regions for which we lacked data.


Assuntos
Apolipoproteínas E/genética , Disfunção Cognitiva/epidemiologia , Escolaridade , Genótipo , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Disfunção Cognitiva/etiologia , Estudos de Coortes , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Fatores Sexuais
15.
J Am Med Dir Assoc ; 18(5): 388-395, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28043804

RESUMO

BACKGROUND: The nature and commonality of late-life risk factors for mild cognitive impairment (MCI), dementia, and mortality remain unclear. Our aim was to investigate potential risk factors, simultaneously in a single cohort including many individuals initially with normal cognition and followed for 6 years. METHODS: We classified 873 community-dwelling individuals (70-90 years old and without dementia at baseline) from the Sydney Memory and Ageing Study as cognitively normal (CN), having MCI or dementia, or deceased 6 years after baseline. Associations with baseline demographic, lifestyle, health, and medical factors were investigated, including apolipoprotein (APOE) genotype, MCI at baseline, and reversion from MCI to CN within 2 years of baseline. RESULTS: Eighty-three (9.5%) participants developed dementia and 114 (13%) died within 6 years; nearly 33% had MCI at baseline, of whom 28% reverted to CN within 2 years. A core set of baseline factors was associated with MCI and dementia at 6 years, including older age (per year: odds ratios and 95% confidence intervals = 1.08, 1.01-1.14 for MCI; 1.19, 1.09-1.31 for dementia), MCI at baseline (5.75, 3.49-9.49; 8.23, 3.93-17.22), poorer smelling ability (per extra test point: 0.89, 0.79-1.02; 0.80, 0.68-0.94), slower walking speed (per second: 1.12, 1.00-1.25; 1.21, 1.05-1.39), and being an APOE ε4 carrier (1.84, 1.07-3.14; 3.63, 1.68-7.82). All except APOE genotype were also associated with mortality (age: 1.11, 1.03-1.20; MCI: 3.87, 1.97-7.59; smelling ability: 0.83, 0.70-0.97; walking speed: 1.18, 1.03-1.34). Compared with stable CN participants, individuals reverting from MCI to CN after 2 years were at greater risk of future MCI (3.06, 1.63-5.72). Those who reverted exhibited some different associations between baseline risk factors and 6-year outcomes than individuals with stable MCI. CONCLUSION: A core group of late-life risk factors indicative of physical and mental frailty are associated with each of dementia, MCI, and mortality after 6 years. Tests for slower walking speed and poorer smelling ability may help screen for cognitive decline. Individuals with normal cognition are at greater risk of future cognitive impairment if they have a history of MCI.


Assuntos
Disfunção Cognitiva/mortalidade , Demência/mortalidade , Mortalidade/tendências , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Humanos , Masculino , Testes Neuropsicológicos , New South Wales/epidemiologia , Fatores de Risco
16.
PLoS One ; 10(11): e0142388, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26539987

RESUMO

BACKGROUND: Changes in criteria and differences in populations studied and methodology have produced a wide range of prevalence estimates for mild cognitive impairment (MCI). METHODS: Uniform criteria were applied to harmonized data from 11 studies from USA, Europe, Asia and Australia, and MCI prevalence estimates determined using three separate definitions of cognitive impairment. RESULTS: The published range of MCI prevalence estimates was 5.0%-36.7%. This was reduced with all cognitive impairment definitions: performance in the bottom 6.681% (3.2%-10.8%); Clinical Dementia Rating of 0.5 (1.8%-14.9%); Mini-Mental State Examination score of 24-27 (2.1%-20.7%). Prevalences using the first definition were 5.9% overall, and increased with age (P < .001) but were unaffected by sex or the main races/ethnicities investigated (Whites and Chinese). Not completing high school increased the likelihood of MCI (P ≤ .01). CONCLUSION: Applying uniform criteria to harmonized data greatly reduced the variation in MCI prevalence internationally.


Assuntos
Disfunção Cognitiva/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Ásia/epidemiologia , Austrália/epidemiologia , Comportamento Cooperativo , Estudos Transversais , Demência/epidemiologia , Progressão da Doença , Europa (Continente)/epidemiologia , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Prevalência
17.
Int J Geriatr Psychiatry ; 30(9): 985-93, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25581393

RESUMO

OBJECTIVE: Neuroticism has been reported as both a risk factor for cognitive decline and a characteristic that increases in parallel with the development of mild cognitive impairment (MCI) and dementia. However, the evidence for these associations is inconclusive, and whether effects are stronger for particular cognitive domains is unknown. We investigated these issues and determined if associations differ among different components of neuroticism. METHODS: A neuroticism scale (NEO-FFI) and neuropsychological test battery were administered to 603 older adults without dementia, with 493 of these reassessed two years later. Diagnoses of MCI and dementia (at follow-up) were made, and global cognition and performance in six cognitive domains quantified. The neuroticism components were negative affect, self-reproach, and proneness to psychological distress. RESULTS: For the whole sample, neuroticism scores remained stable between baseline (15.3 ± 7.0) and follow-up (15.5 ± 7.0), as did all neuroticism component scores. However, there were declines in global cognition (p < 0.05) and particular cognitive domains (p < 0.001). Higher neuroticism was associated with poorer cognition cross-sectionally (p < 0.01), but did not predict cognitive decline. For 43 participants who developed incident MCI or dementia, there were increases in neuroticism (15.3 ± 6.4 to 17.1 ± 8.3, p < 0.05) and negative affect (p < 0.05). Declines in all cognitive measures except executive function were associated with increases in neuroticism and component scores (p < 0.05). CONCLUSIONS: Late-life cognitive decline is associated with an increase in neuroticism scores. However, associations vary between different cognitive domains and components of neuroticism. An increase in neuroticism or negative affect scores may be a sign of MCI or dementia.


Assuntos
Transtornos de Ansiedade/fisiopatologia , Cognição/fisiologia , Disfunção Cognitiva/psicologia , Demência/psicologia , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Disfunção Cognitiva/diagnóstico , Demência/diagnóstico , Função Executiva/fisiologia , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Neuroticismo , Fatores de Risco
18.
J Neurol Neurosurg Psychiatry ; 85(12): 1324-30, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24659793

RESUMO

OBJECTIVES: To examine how cognitive deficits progress in the years following a stroke or transient ischaemic attack (TIA). METHODS: A follow-up study, with neuropsychological and MRI assessments undertaken 3 years after baseline assessments made 3-6 months poststroke in 183 stroke/TIA patients and 97 healthy controls participating in the Sydney Stroke Study. Additional measures included cardiovascular risk factors and apolipoprotein E (APOE) genotype. RESULTS: Stroke/TIA patients had poorer cognitive function and more vascular risk factors than controls at baseline, but did not show greater decline in cognitive function over 3 years except for verbal memory. Patients with a subsequent stroke/TIA showed greater decline in global cognitive function and a number of domains. Rates of incident dementia were 5.9% per year in patients and 0.4% in controls. Both groups showed increased atrophy of the hippocampus, amygdala and whole brain, and an increase in white matter hyperintensities over 3 years; whole brain atrophy was greater in patients. Cognitive decline was greater in women and in those with smaller hippocampi at baseline. For patients without a subsequent stroke/TIA, those with smaller hippocampi or the APOE ε4 allele had greater global cognitive and verbal memory decline. CONCLUSIONS: In poststroke patients, cognitive decline was not greater than in comparison subjects, except for verbal memory, unless they had another stroke/TIA. However, dementia incidence was higher in patients, as might be expected from their poorer baseline cognitive functioning. Smaller hippocampi were associated with an increased risk of decline in memory, and APOE ε4 was a risk factor in those without a subsequent stroke/TIA.


Assuntos
Transtornos Cognitivos/etiologia , Ataque Isquêmico Transitório/complicações , Acidente Vascular Cerebral/complicações , Idoso , Idoso de 80 Anos ou mais , Apolipoproteínas E/genética , Encéfalo/patologia , Doenças Cardiovasculares/etiologia , Estudos de Casos e Controles , Transtornos Cognitivos/patologia , Demência/etiologia , Demência/patologia , Progressão da Doença , Feminino , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Neuroimagem , Testes Neuropsicológicos , Fatores de Risco , Fatores de Tempo
19.
Age (Dordr) ; 36(2): 977-93, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24402401

RESUMO

Type 2 diabetes predicts accelerated cognitive decline and brain atrophy. We hypothesized that impaired fasting glucose (IFG) and incident glucose disorders have detrimental effects on global cognition and brain volume. We further hypothesized that metabolic and inflammatory derangements accompanying hyperglycaemia contribute to change in brain structure and function. This was a longitudinal study of a community-dwelling elderly cohort with neuropsychological testing (n = 880) and brain volumes by magnetic resonance imaging (n = 312) measured at baseline and 2 years. Primary outcomes were global cognition and total brain volume. Secondary outcomes were cognitive domains (processing speed, memory, language, visuospatial and executive function) and brain volumes (hippocampal, parahippocampal, precuneus and frontal lobe). Participants were categorised as normal, impaired fasting glucose at both assessments (stable IFG), baseline diabetes or incident glucose disorders (incident diabetes or IFG at 2 years). Measures included inflammatory cytokines and oxidative metabolites. Covariates were age, sex, education, non-English speaking background, smoking, blood pressure, lipid-lowering or antihypertensive medications, mood score, apolipoprotein E genotype and baseline cognition or brain volume. Participants with incident glucose disorders had greater decline in global cognition and visuospatial function compared to normal, similar to that observed in baseline diabetes. Homocysteine was independently associated with the observed effect of diabetes on executive function. Apolipoprotein E genotype did not influence the observed effects of diabetes on cognition. Incident glucose disorders and diabetes were also associated with greater 2-year decline in total brain volume, compared to normal (40.0 ± 4.2 vs. 46.7 ± 5.7 mm(3) vs. 18.1 ± 6.2, respectively, p < 0.005). Stable IFG did not show greater decline in global cognition or brain volumes compared to normal. Incident glucose disorders, like diabetes, are associated with accelerated decline in global cognition and brain volumes in non-demented elderly, whereas stable IFG is not. Preventing deterioration in glucose metabolism in the elderly may help preserve brain structure and function.


Assuntos
Envelhecimento , Glicemia/metabolismo , Encéfalo/patologia , Transtornos Cognitivos/etiologia , Cognição/fisiologia , Hiperglicemia/complicações , Memória/fisiologia , Idoso , Idoso de 80 Anos ou mais , Atrofia , Encéfalo/fisiopatologia , Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/epidemiologia , Feminino , Seguimentos , Humanos , Hiperglicemia/sangue , Hiperglicemia/epidemiologia , Incidência , Imagem por Ressonância Magnética , Masculino , Testes Neuropsicológicos , New South Wales/epidemiologia , Estudos Retrospectivos
20.
J Gerontol B Psychol Sci Soc Sci ; 69(4): 514-22, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23668997

RESUMO

OBJECTIVES: We aimed to examine associations between each of three leisure activities (Cognitive, Physical, and Social) and performance in selected cognitive domains (Speed, Memory, Verbal ability, and Executive functions) and global cognition. We also aimed to explore associations between medical and health factors and late-life cognition. METHOD: Our sample comprised 119 pairs of monozygotic twins from the Older Australian Twins Study. Their mean age was 71 years and 66% were women. We used a discordant co-twin design, with cognitive performance measures as dependent variables and leisure activities as independent variables. Multiple regression analyses were performed, adjusting for potentially relevant medical and health factors. RESULTS: Discordance in Cognitive Activity and Social Activity participation was positively associated with discordance in performance on some cognitive domains. There were no associations between Physical Activity participation and cognition. Discordance in several cardiovascular, frailty, and sensory variables was associated with discordance in cognitive performance measures. DISCUSSION: This study identified lifestyle and health-related influences on late-life cognition. Our findings not only help in understanding the neurobiological mechanisms, they also have practical implications for interventions to prevent or slow age-related cognitive decline.


Assuntos
Envelhecimento/fisiologia , Cognição/fisiologia , Nível de Saúde , Atividades de Lazer , Gêmeos Monozigóticos/estatística & dados numéricos , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/genética , Austrália/epidemiologia , Feminino , Humanos , Masculino , Atividade Motora/genética , Atividade Motora/fisiologia , Testes Neuropsicológicos
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