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1.
Artigo em Inglês | MEDLINE | ID: mdl-32405646

RESUMO

BACKGROUND: Excessive daytime sleepiness is associated with chronic disorders of aging and mortality. Because longitudinal data are limited on the development of sleep disturbances and cognitive changes in older adults, we investigated the demographic, clinical, and cognitive predictors of self-reported daytime sleepiness over ten years. METHODS: We jointly modeled latent trajectories over time of sleepiness, cognitive domains, and informative attrition, and then fit models to identify cognitive trajectories and baseline characteristics that predicted the trajectories of sleepiness. RESULTS: Three latent trajectory groups were identified: emerging sleepiness, persistent sleepiness, and consistently low daytime sleepiness accounting for attrition in all groups. Compared to low sleepiness, emerging sleepiness was significantly associated with declining attention and subjective memory complaints; persistent sleepiness was associated with lower baseline scores in all cognitive domains, declining language trajectory, and more subjective memory complaints. CONCLUSIONS: These findings suggest that persistent and emerging daytime sleepiness are associated with cognitive decline and multiple morbidities, albeit more subtly in emerging daytime sleepiness. Further, these data suggest that change in the cognitive domain of attention and subjective memory complaints may be early indicators of future sleep disturbance.

2.
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.

3.
Int Psychogeriatr ; : 1-12, 2020 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-32301414

RESUMO

BACKGROUND: Longitudinal studies predictably experience non-random attrition over time. Among older adults, risk factors for attrition may be similar to risk factors for outcomes such as cognitive decline and dementia, potentially biasing study results. OBJECTIVE: To characterize participants lost to follow-up which can be useful in the study design and interpretation of results. METHODS: In a longitudinal aging population study with 10 years of annual follow-up, we characterized the attrited participants (77%) compared to those who remained in the study. We used multivariable logistic regression models to identify attrition predictors. We then implemented four machine learning approaches to predict attrition status from one wave to the next and compared the results of all five approaches. RESULTS: Multivariable logistic regression identified those more likely to drop out as older, male, not living with another study participant, having lower cognitive test scores and higher clinical dementia ratings, lower functional ability, fewer subjective memory complaints, no physical activity, reported hobbies, or engagement in social activities, worse self-rated health, and leaving the house less often. The four machine learning approaches using areas under the receiver operating characteristic curves produced similar discrimination results to the multivariable logistic regression model. CONCLUSIONS: Attrition was most likely to occur in participants who were older, male, inactive, socially isolated, and cognitively impaired. Ignoring attrition would bias study results especially when the missing data might be related to the outcome (e.g. cognitive impairment or dementia). We discuss possible solutions including oversampling and other statistical modeling approaches.

4.
Exp Gerontol ; 137: 110948, 2020 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-32302664

RESUMO

BACKGROUND: Evidence suggests that better cognitive functioning is associated with better mobility in older age. It is unknown whether older adults with better cognitive function are more resilient to mobility decline after a fall. METHODS: Participants from the Monongahela Youghiogheny Healthy Aging Team (MYHAT) study were followed annually for up to 9 years for incident falls. We examined one-year (mean 1.0 year, SD 0.1) change in mobility pre- to post-fall using the Timed Up and Go (TUG) in relation to pre-fall cognition (executive function, attention, memory, and visuospatial function) among incident fallers (n = 598, mean age 79.1, SD = 7.0). Linear regression models tested the association of cognition with change in TUG. Interaction terms were tested to explore if age, sex, body mass index, physical activity, depressive symptoms, or visual acuity modified the associations of cognition and mobility among fallers. The association between cognition and one-year change in TUG was also tested in a comparison sample of non-fallers (n = 442, mean age 76.3, SD = 7.2). RESULTS: Overall, mobility decline was greater in fallers compared to non-fallers. In fully-adjusted models, higher executive function, but not attention, memory, or visuospatial function, was associated with less decline in mobility among incident fallers. The effect was significantly stronger for those who were older, sedentary, and had lower body mass index. Higher scores in memory tests, but not in other domains, was associated with less mobility decline among non-fallers. CONCLUSIONS: Higher executive function may offer resilience to mobility decline after a fall, especially among older adults with other risk factors for mobility decline. Future studies should assess whether executive function may be a helpful risk index of fall-related physical functional decline in geriatric settings.

5.
J Am Geriatr Soc ; 68(5): 991-998, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32020605

RESUMO

BACKGROUND/OBJECTIVES: To investigate potential mechanisms underlying the well-established relationship of diabetes and obesity with cognitive decline, among older adults participating in a population-based study. DESIGN/SETTING: Ten-year population-based cohort study. PARTICIPANTS: A total of 478 individuals aged 65 years and older. MEASUREMENTS: We assayed fasting blood for markers of glycemia (glucose and hemoglobin A1c [HbA1c]), insulin resistance (IR) (insulin and homeostatic model assessment of IR), obesity (resistin, adiponectin, and glucagon-like peptide-1), and inflammation (C-reactive protein). We modeled these indices as predictors of the slope of decline in global cognition, adjusting for age, sex, education, APOE*4 genotype, depressive symptoms, waist-hip ratio (WHR), and systolic blood pressure, in multivariable regression analyses of the entire sample and stratified by sex-specific median WHR. We then conducted WHR-stratified machine-learning (Classification and Regression Tree [CART]) analyses of the same variables. RESULTS: In multivariable regression analyses, in the entire sample, HbA1c was significantly associated with cognitive decline. After stratifying by median WHR, HbA1c remained associated with cognitive decline in those with higher WHR. No metabolic indices were associated with cognitive decline in those with lower WHR. Cross-validated WHR-stratified CART analyses selected no predictors in participants older than 87 to 88 years. Faster cognitive decline was associated, in lower WHR participants younger than 87 years, with adiponectin of 11 or greater; and in higher WHR participants younger than 88 years, with HbA1c of 6.2% or greater. CONCLUSIONS: Our population-based data suggest that, in individuals younger than 88 years with central obesity, even modest degrees of hyperglycemia might independently predispose to faster cognitive decline. In contrast, among those younger than 87 years without central obesity, adiponectin may be a novel independent risk factor for cognitive decline. J Am Geriatr Soc 68:991-998, 2020.

6.
Neurology ; 94(3): e267-e281, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31827004

RESUMO

OBJECTIVE: High blood pressure is one of the main modifiable risk factors for dementia. However, there is conflicting evidence regarding the best antihypertensive class for optimizing cognition. Our objective was to determine whether any particular antihypertensive class was associated with a reduced risk of cognitive decline or dementia using comprehensive meta-analysis including reanalysis of original participant data. METHODS: To identify suitable studies, MEDLINE, Embase, and PsycINFO and preexisting study consortia were searched from inception to December 2017. Authors of prospective longitudinal human studies or trials of antihypertensives were contacted for data sharing and collaboration. Outcome measures were incident dementia or incident cognitive decline (classified using the reliable change index method). Data were separated into mid and late-life (>65 years) and each antihypertensive class was compared to no treatment and to treatment with other antihypertensives. Meta-analysis was used to synthesize data. RESULTS: Over 50,000 participants from 27 studies were included. Among those aged >65 years, with the exception of diuretics, we found no relationship by class with incident cognitive decline or dementia. Diuretic use was suggestive of benefit in some analyses but results were not consistent across follow-up time, comparator group, and outcome. Limited data precluded meaningful analyses in those ≤65 years of age. CONCLUSION: Our findings, drawn from the current evidence base, support clinical freedom in the selection of antihypertensive regimens to achieve blood pressure goals. CLINICAL TRIALS REGISTRATION: The review was registered with the international prospective register of systematic reviews (PROSPERO), registration number CRD42016045454.

7.
Am J Geriatr Psychiatry ; 28(1): 99-107, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31300193

RESUMO

OBJECTIVES: To investigate potential birth cohort effects in depression symptoms in older adults. DESIGN: Population-based prospective cohort. SETTING: Small-town communities in Pennsylvania. PARTICIPANTS: Three thousand two hundred and twenty seven older adults (average baseline age = 71.6) born between 1902 and 1941. MEASUREMENTS: Four decade-long birth cohorts were the primary predictors in this study: 1902-1911, 1912-1921, 1922-1931, and 1932-1941. The outcome was symptoms of depression assessed at baseline and follow-up study visits using a modified Center for Epidemiologic Studies Depression Scale (mCES-D). The depression outcome was operationalized as: 1). A binary outcome of having greater than equal to 5 depression symptoms on the total mCES-D at any study visit, and 2). A continuous outcome of four factor-analyzed component scores of the mCES-D including depressed mood, anergia/hopelessness, withdrawal, and poor self-esteem. All analyses were jointly modeled with attrition and adjusted for age, sex, education, Mini Mental State Examination score, antidepressant medications, and total prescription medications. RESULTS: Participants from more recently born cohorts were significantly less likely to have a study visit in which they reported greater than or equal to 5 depression symptoms, controlling for attrition. Specifically, in comparison to the 1902-1911 referent cohort, the 1912-1921 birth cohort was 43% less likely (odds ratio [OR] = 0.566, 95% confidence interval [CI]: 0.341-0.939), the 1922-1931 birth cohort was 63% less likely (OR = 0.0369, 95% CI: 0.215-0.632), and the 1932-1941 cohort was 79% less likely (OR = 0.205, 95% CI: 0.106-0.399). The cohort effect was most evident in the depressed mood and anergia/hopelessness symptom composites. CONCLUSION: Reduced rates of depression symptoms observed in successive birth cohorts of older adults may reflect compression of morbidity or other secular trends.

8.
J Sleep Res ; : e12952, 2019 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-31782578

RESUMO

Several studies have associated daytime sleepiness with risk of dementia, but it is unknown whether longstanding and emerging daytime sleepiness equally signal a risk of dementia, and whether other health factors explain these associations. In a prospective, population-based epidemiologic study, we (i) assessed associations of daytime sleepiness trajectories over 10 years with dementia incidence and (ii) examined whether selected health characteristics attenuated these associations. Using latent group-based trajectory analysis we categorized participants into three groups: (i) no daytime sleepiness (n = 959, 49.2%), (ii) emerging daytime sleepiness (n = 342, 17.5%) and (iii) persistent daytime sleepiness (n = 650, 33.3%). Compared with no daytime sleepiness, emerging and persistent daytime sleepiness were similarly associated with greater incident dementia risk (respective hazard ratios [95% confidence intervals] were 2.2 [1.3, 3.5] and 1.9 [1.2, 3.1]). Baseline blood pressure, body mass index, chronic disease diagnoses and symptoms of depression did not attenuate these associations. In contrast, lack of independence in instrumental activities of daily living attenuated the daytime sleepiness-dementia association by approximately 17%-21%. These findings suggest that persistent and emerging daytime sleepiness may signal a risk of dementia. However, the underlying mechanisms remain unclear. Further studies should investigate whether and how pathways to sleepiness, functional impairment and dementia pathophysiology interrelate and manifest together over time.

9.
Alzheimer Dis Assoc Disord ; 33(4): 291-298, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31567145

RESUMO

BACKGROUND: Linear models cannot capture nonlinear associations when the relationships between cognition and risk factors vary across risk levels. We demonstrate a method of modelling nonlinear associations using the example of blood pressure (BP) and memory. METHODS: We measured memory and BP (in mm Hg) annually for 10 years in a population-based cohort (N=1982) aged 65+. We evaluated the relationship between BP and memory at the same time points using both linear mixed models and generalized additive mixed models with smoothing splines, adjusting for relevant covariates. RESULTS: Linear mixed models found no significant associations. Generalized additive mixed models detected different associations between BP and memory across baseline BP categories (normotensive, hypertensive, hypotensive). Among normotensives, systolic blood pressure (SBP)/diastolic blood pressure (DBP) around 140/80 was associated with the highest, while SBP/DBP around 110/60 was associated with the lowest, predicted memory scores. Among hypertensives, SBP/DBP around 130/85 was associated with the highest, while SBP/DBP around 150/65 was associated with the lowest, predicted memory scores. Among hypotensives, no significant association was found. Among both normotensives and hypertensives, a DBP >75 was associated with better memory. CONCLUSIONS: By modelling nonlinear associations, we showed that the relationship between BP and memory performance varied by baseline BP among normotensives and hypertensives.

10.
Artigo em Inglês | MEDLINE | ID: mdl-31633558

RESUMO

OBJECTIVE: To examine older adults' use over time of agents to treat or prevent dementia or enhance memory. DESIGN: Longitudinal community study with 10-year annual follow-up (2006-2017). SETTING: Population-based cohort. PARTICIPANTS: A total of 1982 individuals with a mean (SD) age of 77 (7.4) years at baseline. MEASUREMENTS: Demographics, self-report, direct inspection of prescription antidementia drugs and nonprescription supplements, cognitive and functional assessments, Clinical Dementia Rating (CDR®) Dementia Staging Instrument. RESULTS: Supplement use was reported by 27% to 42% of participants over 10 years. Use was associated with younger age, high school or greater education, good to excellent self-reported health, higher memory test scores, and absence of cognitive impairment or dementia (CDR=0). Over the same period, about 2% to 6% of participants took prescription dementia medications over 10 years. Use was associated with lower memory test scores, at least mild cognitive impairment (CDR≥0.5), fair to poor self-rated health, and high school or lesser education. CONCLUSIONS: The use of both prescription drugs and supplements increased over time, except for decreases in ginkgo and vitamin E. Prescription drug use appeared in line with prescribing guidelines. Supplement use was associated with higher education and better self-rated health; it persists despite a lack of supportive evidence.

11.
Int Psychogeriatr ; 31(10): 1421-1432, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31455442

RESUMO

OBJECTIVES: To assess independent and joint effects of pairs of vascular and cardiometabolic risk factors (VCMRFs) in relation to risk of all-cause dementia. DESIGN: Population-based longitudinal cohort study of cognitive impairment. We used an algorithm to select pairs of VCMRFs and tested their joint effects in time-dependent Cox models. We used attributable proportions (AP) to measure the proportion of risk from interactions beyond any additive effect. SETTING: Economically depressed small-town population. PARTICIPANTS: Adults age 65+ years with up to 10 yearly study visits (N=1701, median (Q1, Q3) age, 78 (71.0, 83.0), 62.3% female, 94.9% white). RESULTS: Among 1701 participants free from prevalent dementia with at least one follow-up visit, 109 developed incident all-cause dementia. In pairings of APOE*4 with hypertension (HTN) and congestive heart failure (CHF), the variables contributed independently and additively to all-cause dementia risk. In pairings of APOE*4 with stroke and stroke with CHF, the variables demonstrated independent contributions to all-cause dementia risk; their joint effects showed excess detriment demonstrating synergistic interactions (joint HR [95% CI]: 28.33 [6.74, 119.01] and 50.30 [14.57, 173.57] respectively, fully adjusted models). Physical activity (PA) was independently associated with lower all-cause dementia risk when paired with APOE*4, stroke, and CHF in unadjusted models; these associations did not survive covariate adjustment. The joint effect of low PA and APOE*4 was associated with additively increased all-cause dementia risk (joint HR [95% CI]: 4.61 [2.07, 10.23], fully adjusted model). CONCLUSIONS: Reduction of VCMRFs, including low PA, could be valuable for dementia prevention, especially among APOE*4 carriers.

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
13.
Neurobiol Aging ; 84: 239.e15-239.e24, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30954325

RESUMO

To identify novel loci that affect cognitive decline in older adults free of dementia, we conducted genome-wide and gene-based meta-analyses on longitudinal slopes of 5 cognitive domains (memory, executive function, language, attention/processing speed, and visuospatial ability) derived from 2 population-based cohorts. For decline over time in each cognitive domain, we normalized intraindividual slopes within each cohort, accounting for baseline age, sex, and years of education. Normalized slope for each domain was used in cohort-specific genome-wide analyses after including top principal components as covariates followed by genome-wide and gene-based meta-analyses. Both analyses revealed a novel WDFY2 locus at genome-wide (p = 3.37E-08) and gene-wide (p = 7.10E-07) significance levels for the attention/processing speed domain. In the GTEx eQTL analysis, genome-wide significant single-nucleotide polymorphism was associated with RNA expression levels of WDFY2 in several brain regions: cerebellar hemisphere (p = 1.07E-04), cerebellum (p = 6.92E-04), hippocampus (p = 2.18E-03) and cortex (p = 2.29E-02), and in whole blood (p = 4.41E-05). Our results suggest that WDFY2 genetic variation may affect individual differences in decline over time on tests of attention/processing speed.

14.
J Am Geriatr Soc ; 67(2): 232-238, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30444944

RESUMO

BACKGROUND/OBJECTIVE: In population studies, most individuals with mild cognitive impairment (MCI) do not progress to dementia in the near term, but rather remain stable MCI or revert to normal cognition. Here, we characterized MCI subgroups with different outcomes over 5 years. SETTING/PARTICIPANTS: A population-based cohort (N=1603). MEASUREMENTS: Clinical Dementia Rating (CDR); self-reported medical conditions, subjective cognitive concerns, self-rated health, depressive symptoms, blood pressure, medications, blood pressure, APOE genotype, cognitive domain composite scores. DESIGN: We compared 3 MCI subgroups who progressed to dementia (n=86), stabilized at MCI (n=384), or reverted to normal (n=252), to those who remained consistently normal (n=881), defining MCI as CDR = 0.5 and dementia as CDR≥1. Using multinomial logistic regression models adjusted for demographics, we examined the associations of each group with selected baseline characteristics. RESULTS: With the normal group for reference, worse subjective cognitive concerns, functional impairments, self-rated health, and depressive symptoms were associated with being in any MCI group. Taking more prescription medications was associated with being in the stable MCI and reverter groups; diabetes and low diastolic blood pressure were associated with stable MCI. The APOE4 genotype was associated with stable and progressive MCI; stroke was associated with progressive MCI. All MCI subgroups were likely to have lower mean composite scores in all cognitive domains and more operationally defined impairments in attention, language, and executive function; reverters were more likely to lack memory and visuospatial impairments. CONCLUSIONS: MCI subgroups with different 5-year outcomes had some distinct characteristics suggesting different underlying causes. The progressors, unlike the reverters, had a profile broadly typical of Alzheimer's disease; the stable MCIs had other, including vascular, morbidity. These data shed light on the heterogeneity of MCI in the population. J Am Geriatr Soc 67:232-238, 2019.


Assuntos
Cognição , Disfunção Cognitiva/psicologia , Demência/epidemiologia , Progressão da Doença , Idoso , Idoso de 80 Anos ou mais , Apolipoproteína E4/análise , Pressão Sanguínea , Disfunção Cognitiva/genética , Disfunção Cognitiva/fisiopatologia , Estudos de Coortes , Demência/psicologia , Feminino , Humanos , Modelos Logísticos , Masculino , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/psicologia
15.
J Gerontol A Biol Sci Med Sci ; 74(9): 1439-1445, 2019 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-30312371

RESUMO

BACKGROUND: Incidence rates of dementia appear to be declining in high-income countries according to several large epidemiological studies. We aimed to describe declining incident dementia rates across successive birth cohorts in a U.S. population-based sample and to explore the influences of sex and education on these trends. METHODS: We pooled data from two community-sampled prospective cohort studies with similar study aims and contiguous sampling regions: the Monongahela Valley Independent Elders Survey (1987-2001) and the Monongahela-Youghiogheny Healthy Aging Team (2006-Ongoing). We identified four decade-long birth cohorts spanning birth years 1902-1941. In an analysis sample of 3,010 participants (61% women, mean baseline age = 75.7 years, mean follow-up = 7.1 years), we identified 257 cases of incident dementia indicated by a Clinical Dementia Rating of 1.0 or higher. We used Poisson regression to model incident dementia rates by birth cohort, age, sex, education, and interactions of Sex × Cohort and Sex × Education. We further examined whether cohort effects varied by education, testing a Cohort × Education interaction and stratifying the models by education. RESULTS: Compared to the earliest birth cohort (1902-1911), each subsequent cohort had a significantly lower incident dementia rate (1912-1921: incidence rate ratio [IRR] = 0.655, 95% confidence interval [95% CI] = 0.477-0.899; 1922-1931: IRR = 0.387, 95% CI = 0.265-0.564; 1932-1941: IRR = 0.233, 95% CI = 0.121-0.449). We observed no significant interactions of either sex or education with birth cohort. CONCLUSIONS: A decline in incident dementia rates was observed across successive birth cohorts independent of sex, education, and age.

17.
Age Ageing ; 47(4): 558-564, 2018 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-29546417

RESUMO

BACKGROUND: physical function (PF) and physical activity (PA) both decline as adults age and have been linked to negative outcomes, including dementia, depression and cardiovascular diseases. Although declines in each are associated with numerous negative outcomes, the longitudinal relationship between these two measures is unclear. OBJECTIVE: to examine the dynamic, bidirectional associations between declines in PF and PA. DESIGN: prospective cohort. SETTING: the Monongahela-Youghiogheny Healthy Aging Team (MYHAT) study. SUBJECTS: about 1,404 men and women, 76.96 ± 7.2 years, 62.4% female and 95.2% white. METHODS: over nine annual assessment cycles, PF was evaluated via the timed Up-and-Go task and PA via a self-reported questionnaire. Piecewise latent growth models examined bidirectional associations between PA and PF to determine whether the initial values (intercept) or early slope (cycles 1-5) (in either PF or PA) predicted later slope (cycles 5-9) (in either PF or PA). RESULTS: initial PF significantly predicted early (standardised ß= -0.10, P < 0.001) and later (standardised ß= -0.09, P = 0.01) PA slopes. Initial PA significantly predicted later (standardised ß = -0.09, P = 0.04) but not early PF slope. Associations were independent of baseline memory test scores, baseline cognitive status, later cognitive status and age. Early physical function slope neither predicts later PA slope nor did early PA slope predict later PF slope (both P values >0.10). CONCLUSIONS: the relationship between PF and PA is bidirectional, with PF more consistently predicting declines of PA, both in the short- and long-term. Intervening on PF impairments may improve PA engagement, which could in turn promote PF and translate to beneficial effects on cognitive function, cardiovascular health and mood.


Assuntos
Envelhecimento , Exercício Físico , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/psicologia , Cognição , Feminino , Avaliação Geriátrica/métodos , Humanos , Estudos Longitudinais , Masculino , Memória , Pennsylvania , Estudos Prospectivos , Fatores de Risco , Fatores de Tempo
18.
Alzheimer Dis Assoc Disord ; 32(1): 1-9, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29319603

RESUMO

Over recent decades, epidemiology has made significant contributions to our understanding of dementia, translating scientific discoveries into population health. Here, we propose reframing dementia epidemiology as "population neuroscience," blending techniques and models from contemporary neuroscience with those of epidemiology and biostatistics. On the basis of emerging evidence and newer paradigms and methods, population neuroscience will minimize the bias typical of traditional clinical research, identify the relatively homogenous subgroups that comprise the general population, and investigate broader and denser phenotypes of dementia and cognitive impairment. Long-term follow-up of sufficiently large study cohorts will allow the identification of cohort effects and critical windows of exposure. Molecular epidemiology and omics will allow us to unravel the key distinctions within and among subgroups and better understand individuals' risk profiles. Interventional epidemiology will allow us to identify the different subgroups that respond to different treatment/prevention strategies. These strategies will inform precision medicine. In addition, insights into interactions between disease biology, personal and environmental factors, and social determinants of health will allow us to measure and track disease in communities and improve population health. By placing neuroscience within a real-world context, population neuroscience can fulfill its potential to serve both precision medicine and population health.


Assuntos
Demência , Epidemiologia/tendências , Neurociências/tendências , Saúde da População , Medicina de Precisão , Envelhecimento , Humanos , Epidemiologia Molecular
19.
Int Psychogeriatr ; 30(10): 1435-1445, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29335040

RESUMO

ABSTRACTBackground:Evidence suggests that semantic interference may be a sensitive indicator of early dementia. We examined the utility of the Semantic Interference Test (SIT), a cognitive stress memory paradigm which taps proactive and retroactive semantic interference, for predicting progression from mild cognitive impairment (MCI) to dementia in both a clinical and a population-based sample. METHODS: Participants with MCI in the clinical (n = 184) and population-based (n = 435) samples were followed for up to four years. We employed receiver operating characteristic (ROC) methods to establish optimal thresholds for four different SIT indices. Threshold performance was compared in the two samples using logistic and Cox proportional hazard regression models. RESULTS: Within four years, 42 (22.8%) MCI individuals in the clinical sample and 45 (10.3%) individuals in the population-based sample progressed to dementia. Overall classification accuracy of SIT thresholds ranged from 61.4% to 84.8%. Different subtests of the SIT had slightly different performance characteristics in the two samples. However, regression models showed that thresholds established in the clinical sample performed similarly in the population sample before and after adjusting for demographics and other baseline neuropsychological test scores. CONCLUSIONS: Despite differences in demographic composition and progression rates, baseline SIT scores predicted progression from MCI to dementia similarly in both samples. Thresholds that best predicted progression were slightly below thresholds established for distinguishing between amnestic MCI and cognitively normal subjects in clinical practice. This confirms the utility of the SIT in both clinical and population-based samples and establishes thresholds most predictive of progression of individuals with MCI.


Assuntos
Doença de Alzheimer/diagnóstico , Disfunção Cognitiva/diagnóstico , Demência/diagnóstico , Progressão da Doença , Idoso , Disfunção Cognitiva/complicações , Florida , Humanos , Masculino , Memória , Testes Neuropsicológicos , Vigilância da População , Modelos de Riscos Proporcionais
20.
Alzheimers Dement ; 14(6): 734-742, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29352855

RESUMO

INTRODUCTION: We compared risk of progression from subjective cognitive decline (SCD) to mild cognitive impairment (MCI) in an academic memory clinic versus a population-based study. METHODS: Older adults presenting at a memory clinic were classified as SCD (n = 113) or as noncomplainers (n = 82). Participants from a population study were classified as SCD (n = 592) and noncomplainers (n = 589) based on a memory complaint score. Annual follow-up performed for a mean of 3 years. RESULTS: The adjusted hazard ratio for SCD was 15.97 (95% confidence interval: 6.08-42.02, P < .001) in the memory clinic versus 1.18 (95% confidence interval: 1.00-1.40, P = .047) in the population study, where reported "worry" about memory further increased SCD-associated risk for MCI. DISCUSSION: SCD is more likely to progress to MCI in a memory clinic than the general population; participants' characteristics vary across settings. Study setting should be considered when evaluating SCD as a risk state for MCI and dementia.


Assuntos
Disfunção Cognitiva/classificação , Progressão da Doença , Transtornos da Memória/classificação , Idoso , Instituições de Assistência Ambulatorial , Disfunção Cognitiva/epidemiologia , Feminino , Humanos , Estudos Longitudinais , Masculino , Testes Neuropsicológicos , Fatores de Risco , Estados Unidos/epidemiologia
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