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1.
JAMA Netw Open ; 7(5): e2412824, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38776079

RESUMO

Importance: Vascular disease is a treatable contributor to dementia risk, but the role of specific markers remains unclear, making prevention strategies uncertain. Objective: To investigate the causal association between white matter hyperintensity (WMH) burden, clinical stroke, blood pressure (BP), and dementia risk, while accounting for potential epidemiologic biases. Design, Setting, and Participants: This study first examined the association of genetically determined WMH burden, stroke, and BP levels with Alzheimer disease (AD) in a 2-sample mendelian randomization (2SMR) framework. Second, using population-based studies (1979-2018) with prospective dementia surveillance, the genetic association of WMH, stroke, and BP with incident all-cause dementia was examined. Data analysis was performed from July 26, 2020, through July 24, 2022. Exposures: Genetically determined WMH burden and BP levels, as well as genetic liability to stroke derived from genome-wide association studies (GWASs) in European ancestry populations. Main Outcomes and Measures: The association of genetic instruments for WMH, stroke, and BP with dementia was studied using GWASs of AD (defined clinically and additionally meta-analyzed including both clinically diagnosed AD and AD defined based on parental history [AD-meta]) for 2SMR and incident all-cause dementia for longitudinal analyses. Results: In 2SMR (summary statistics-based) analyses using AD GWASs with up to 75 024 AD cases (mean [SD] age at AD onset, 75.5 [4.4] years; 56.9% women), larger WMH burden showed evidence for a causal association with increased risk of AD (odds ratio [OR], 1.43; 95% CI, 1.10-1.86; P = .007, per unit increase in WMH risk alleles) and AD-meta (OR, 1.19; 95% CI, 1.06-1.34; P = .008), after accounting for pulse pressure for the former. Blood pressure traits showed evidence for a protective association with AD, with evidence for confounding by shared genetic instruments. In the longitudinal (individual-level data) analyses involving 10 699 incident all-cause dementia cases (mean [SD] age at dementia diagnosis, 74.4 [9.1] years; 55.4% women), no significant association was observed between larger WMH burden and incident all-cause dementia (hazard ratio [HR], 1.02; 95% CI, 1.00-1.04; P = .07). Although all exposures were associated with mortality, with the strongest association observed for systolic BP (HR, 1.04; 95% CI, 1.03-1.06; P = 1.9 × 10-14), there was no evidence for selective survival bias during follow-up using illness-death models. In secondary analyses using polygenic scores, the association of genetic liability to stroke, but not genetically determined WMH, with dementia outcomes was attenuated after adjusting for interim stroke. Conclusions: These findings suggest that WMH is a primary vascular factor associated with dementia risk, emphasizing its significance in preventive strategies for dementia. Future studies are warranted to examine whether this finding can be generalized to non-European populations.


Assuntos
Pressão Sanguínea , Doenças de Pequenos Vasos Cerebrais , Demência , Humanos , Doenças de Pequenos Vasos Cerebrais/genética , Doenças de Pequenos Vasos Cerebrais/epidemiologia , Feminino , Masculino , Idoso , Demência/genética , Demência/epidemiologia , Pressão Sanguínea/genética , Estudo de Associação Genômica Ampla , Análise da Randomização Mendeliana , Doença de Alzheimer/genética , Doença de Alzheimer/epidemiologia , Acidente Vascular Cerebral/genética , Acidente Vascular Cerebral/epidemiologia , Fatores de Risco , Predisposição Genética para Doença , Idoso de 80 Anos ou mais , Estudos Prospectivos
3.
medRxiv ; 2023 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-37790435

RESUMO

Importance: There is increasing recognition that vascular disease, which can be treated, is a key contributor to dementia risk. However, the contribution of specific markers of vascular disease is unclear and, as a consequence, optimal prevention strategies remain unclear. Objective: To disentangle the causal relation of several key vascular traits to dementia risk: (i) white matter hyperintensity (WMH) burden, a highly prevalent imaging marker of covert cerebral small vessel disease (cSVD); (ii) clinical stroke; and (iii) blood pressure (BP), the leading risk factor for cSVD and stroke, for which efficient therapies exist. To account for potential epidemiological biases inherent to late-onset conditions like dementia. Design Setting and Participants: This study first explored the association of genetically determined WMH, BP levels and stroke risk with AD using summary-level data from large genome-wide association studies (GWASs) in a two-sample Mendelian randomization (MR) framework. Second, leveraging individual-level data from large longitudinal population-based cohorts and biobanks with prospective dementia surveillance, the association of weighted genetic risk scores (wGRSs) for WMH, BP, and stroke with incident all-cause-dementia was explored using Cox-proportional hazard and multi-state models. The data analysis was performed from July 26, 2020, through July 24, 2022. Exposures: Genetically determined levels of WMH volume and BP (systolic, diastolic and pulse blood pressures) and genetic liability to stroke. Main outcomes and measures: The summary-level MR analyses focused on the outcomes from GWAS of clinically diagnosed AD (n-cases=21,982) and GWAS additionally including self-reported parental history of dementia as a proxy for AD diagnosis (ADmeta, n-cases=53,042). For the longitudinal analyses, individual-level data of 157,698 participants with 10,699 incident all-cause-dementia were studied, exploring AD, vascular or mixed dementia in secondary analyses. Results: In the two-sample MR analyses, WMH showed strong evidence for a causal association with increased risk of ADmeta (OR, 1.16; 95%CI:1.05-1.28; P=.003) and AD (OR, 1.28; 95%CI:1.07-1.53; P=.008), after accounting for genetically determined pulse pressure for the latter. Genetically predicted BP traits showed evidence for a protective association with both clinically defined AD and ADmeta, with evidence for confounding by shared genetic instruments. In longitudinal analyses the wGRSs for WMH, but not BP or stroke, showed suggestive association with incident all-cause-dementia (HR, 1.02; 95%CI:1.00-1.04; P=.06). BP and stroke wGRSs were strongly associated with mortality but there was no evidence for selective survival bias during follow-up. In secondary analyses, polygenic scores with more liberal instrument definition showed association of both WMH and stroke with all-cause-dementia, AD, and vascular or mixed dementia; associations of stroke, but not WMH, with dementia outcomes were markedly attenuated after adjusting for interim stroke. Conclusion: These findings provide converging evidence that WMH is a leading vascular contributor to dementia risk, which may better capture the brain damage caused by BP (and other etiologies) than BP itself and should be targeted in priority for dementia prevention in the population.

4.
Brain ; 145(6): 1992-2007, 2022 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-35511193

RESUMO

Cerebral small vessel disease is a leading cause of stroke and a major contributor to cognitive decline and dementia, but our understanding of specific genes underlying the cause of sporadic cerebral small vessel disease is limited. We report a genome-wide association study and a whole-exome association study on a composite extreme phenotype of cerebral small vessel disease derived from its most common MRI features: white matter hyperintensities and lacunes. Seventeen population-based cohorts of older persons with MRI measurements and genome-wide genotyping (n = 41 326), whole-exome sequencing (n = 15 965), or exome chip (n = 5249) data contributed 13 776 and 7079 extreme small vessel disease samples for the genome-wide association study and whole-exome association study, respectively. The genome-wide association study identified significant association of common variants in 11 loci with extreme small vessel disease, of which the chr12q24.11 locus was not previously reported to be associated with any MRI marker of cerebral small vessel disease. The whole-exome association study identified significant associations of extreme small vessel disease with common variants in the 5' UTR region of EFEMP1 (chr2p16.1) and one probably damaging common missense variant in TRIM47 (chr17q25.1). Mendelian randomization supports the causal association of extensive small vessel disease severity with increased risk of stroke and Alzheimer's disease. Combined evidence from summary-based Mendelian randomization studies and profiling of human loss-of-function allele carriers showed an inverse relation between TRIM47 expression in the brain and blood vessels and extensive small vessel disease severity. We observed significant enrichment of Trim47 in isolated brain vessel preparations compared to total brain fraction in mice, in line with the literature showing Trim47 enrichment in brain endothelial cells at single cell level. Functional evaluation of TRIM47 by small interfering RNAs-mediated knockdown in human brain endothelial cells showed increased endothelial permeability, an important hallmark of cerebral small vessel disease pathology. Overall, our comprehensive gene-mapping study and preliminary functional evaluation suggests a putative role of TRIM47 in the pathophysiology of cerebral small vessel disease, making it an important candidate for extensive in vivo explorations and future translational work.


Assuntos
Isquemia Encefálica , Doenças de Pequenos Vasos Cerebrais , Acidente Vascular Cerebral , Animais , Isquemia Encefálica/complicações , Doenças de Pequenos Vasos Cerebrais/complicações , Doenças de Pequenos Vasos Cerebrais/diagnóstico por imagem , Doenças de Pequenos Vasos Cerebrais/genética , Células Endoteliais/patologia , Estudo de Associação Genômica Ampla , Camundongos , Acidente Vascular Cerebral/complicações
5.
Artigo em Inglês | MEDLINE | ID: mdl-34700051

RESUMO

BACKGROUND: Subcortical brain structures play a key role in pathological processes of age-related neurodegenerative disorders. Mounting evidence also suggests that early-life factors may have an impact on the development of common late-life neurological diseases, including genetic factors that can influence both brain maturation and neurodegeneration. METHODS: Using large population-based brain imaging datasets across the lifespan (N ≤ 40,628), we aimed to 1) estimate the heritability of subcortical volumes in young (18-35 years), middle (35-65 years), and older (65+ years) age, and their genetic correlation across age groups; 2) identify whether genetic loci associated with subcortical volumes in older persons also show associations in early adulthood, and explore underlying genes using transcriptome-wide association studies; and 3) explore their association with neurological phenotypes. RESULTS: Heritability of subcortical volumes consistently decreased with increasing age. Genetic risk scores for smaller caudate nucleus, putamen, and hippocampus volume in older adults were associated with smaller volumes in young adults. Individually, 10 loci associated with subcortical volumes in older adults also showed associations in young adults. Within these loci, transcriptome-wide association studies showed that expression of several genes in brain tissues (especially MYLK2 and TUFM) was associated with subcortical volumes in both age groups. One risk variant for smaller caudate nucleus volume (TUFM locus) was associated with lower cognitive performance. Genetically predicted Alzheimer's disease was associated with smaller subcortical volumes in middle and older age. CONCLUSIONS: Our findings provide novel insights into the genetic determinants of subcortical volumes across the lifespan. More studies are needed to decipher the underlying biology and clinical impact.


Assuntos
Longevidade , Imageamento por Ressonância Magnética , Adulto , Idoso , Idoso de 80 Anos ou mais , Encéfalo/patologia , Genômica , Humanos , Imageamento por Ressonância Magnética/métodos , Tamanho do Órgão
6.
Front Neurol ; 12: 675244, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34093421

RESUMO

Background and Objectives: Young adults represent an increasingly large proportion of healthy volunteers in brain imaging research, but descriptions of incidental findings (IFs) in this age group are scarce. We aimed to assess the prevalence and severity of IFs on brain MRIs of healthy young research participants aged 18-35 years, and to describe the protocol implemented to handle them. Methods: The study population comprised 1,867 participants aged 22.1 ± 2.3 years (72% women) from MRi-Share, the cross-sectional brain MRI substudy of the i-Share student cohort. IFs were flagged during the MRI quality control. We estimated the proportion of participants with IFs [any, requiring medical referral, potentially serious (PSIFs) as defined in the UK biobank]: overall, by type and severity of the final diagnosis, as well as the number of IFs. Results: 78/1,867 participants had at least one IF [4.2%, 95% Confidence Interval (CI) 3.4-5.2%]. IFs requiring medical referral (n = 38) were observed in 36/1,867 participants (1.9%, 1.4-2.7%), and represented 47.5% of the 80 IFs initially flagged. Referred IFs were retrospectively classified as PSIFs in 25/1,867 participants (1.3%, 0.9-2.0%), accounting for 68.4% of anomalies referred (26/38). The most common final diagnosis was cysts or ventricular abnormalities in all participants (9/1,867; 0.5%, 0.2-0.9%) and in those with referred IFs (9/36; 25.0%, 13.6-41.3%), while it was multiple sclerosis or radiologically isolated syndrome in participants with PSIFs (5/19; 26.3%, 11.5-49.1%) who represented 0.1% (0.0-0.4%) and 0.2% (0.03-0.5%) of all participants, respectively. Final diagnoses were considered serious in 11/1,867 participants (0.6%, 0.3-1.1%). Among participants with referred IFs, 13.9% (5/36) required active intervention, while 50.0% (18/36) were put on clinical surveillance. Conclusions: In a large brain imaging study of young healthy adults participating in research we observed a non-negligible frequency of IFs. The etiological pattern differed from what has been described in older adults.

7.
Stroke ; 51(2): 402-408, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31826735

RESUMO

Background and Purpose- Evidence links antidepressant use with cerebral small vessel disease; however, it remains unclear whether people with depression face comparable risk. This study aims to determine the association between antidepressant drug use and depression with markers of cerebral small vessel disease. Methods- One thousand nine hundred five participants (mean age, 72.5 years; 60% women) without stroke or dementia history underwent brain magnetic resonance imaging at baseline, and 1402 individuals underwent a second magnetic resonance imaging at 4 years. Outcomes were lacunes 3 to 15 mm and white matter hyperintensity volume (cm3) at baseline and follow-up. Exposure to antidepressants was grouped as (1) selective serotonin reuptake inhibitors (n=68), (2) tricyclics (n=40), (3) atypicals (n=24), (4) depressed nonusers (n=303), and (5) nondepressed/nonuser group (reference group, n=1470). Statistical analyses adjusted for propensity scores due to the nonrandomized exposure to antidepressant drugs. Results- There was an association between use of atypical antidepressants with lacunes at baseline (adjusted rate ratio, 2.59 [95% CI, 1.14-5.88]; P=0.023) and follow-up (adjusted rate ratio, 3.05 [95% CI, 1.25-7.43]; P=0.014). Lacunes at baseline were also associated with depressed nonusers (adjusted rate ratio, 1.53 [95% CI, 1.06-2.21]; P=0.023). Selective serotonin reuptake inhibitor users and depressed nonusers displayed higher total, periventricular, and deep white matter hyperintensity volumes at baseline. Selective serotonin reuptake inhibitor users had higher deep white matter hyperintensity volumes at follow-up. Conclusions- Users of atypical antidepressants, selective serotonin reuptake inhibitors, and depressed people without any antidepressant exposure all displayed markers of cerebral small vessel disease higher than the nondepressed/nonuser group. The findings suggest that cerebral small vessel disease is associated with depression and exposure to antidepressants.


Assuntos
Antidepressivos/uso terapêutico , Doenças de Pequenos Vasos Cerebrais/epidemiologia , Transtorno Depressivo/epidemiologia , Substância Branca/diagnóstico por imagem , Idoso , Antidepressivos de Segunda Geração/uso terapêutico , Antidepressivos Tricíclicos/uso terapêutico , Estudos de Casos e Controles , Doenças de Pequenos Vasos Cerebrais/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Inibidores Seletivos de Recaptação de Serotonina/uso terapêutico
8.
Neurobiol Aging ; 84: 158-165, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31629114

RESUMO

Commonly observed in older community persons, dilated perivascular spaces (dPVSs) are thought to represent an emerging MRI marker of cerebral small vessel disease, but their clinical significance is uncertain. We examined the longitudinal relationship of dPVS burden with risk of incident stroke, ischemic stroke, and intracerebral hemorrhage (ICH) in the 3C-Dijon population-based study (N = 1678 participants, mean age 72.7 ± 4.1 years) using Cox regression. dPVS burden was studied as a global score and according to dPVS location (basal ganglia, white matter, hippocampus, brainstem) at the baseline. During a mean follow-up of 9.1 ± 2.6 years, 66 participants suffered an incident stroke. Increasing global dPVS burden was associated with a higher risk of any incident stroke (hazard ratio [HR], 1.24; 95% CI, [1.06-1.45]) and of incident ICH (HR, 3.12 [1.78-5.47]), adjusting for sex and intracranial volume. Association with ICH remained significant after additionally adjusting for vascular risk factors and for other cerebral small vessel disease MRI markers. High dPVS burden in basal ganglia and hippocampus, but not in white matter or brainstem, were associated with higher risk of any stroke and ICH.


Assuntos
Envelhecimento/patologia , Hemorragia Cerebral/diagnóstico por imagem , Hemorragia Cerebral/etiologia , Sistema Glinfático/diagnóstico por imagem , Sistema Glinfático/patologia , Idoso , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Risco
9.
Brain ; 142(4): 1009-1023, 2019 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-30859180

RESUMO

We report a composite extreme phenotype design using distribution of white matter hyperintensities and brain infarcts in a population-based cohort of older persons for gene-mapping of cerebral small vessel disease. We demonstrate its application in the 3C-Dijon whole exome sequencing (WES) study (n = 1924, nWESextremes = 512), with both single variant and gene-based association tests. We used other population-based cohort studies participating in the CHARGE consortium for replication, using whole exome sequencing (nWES = 2,868, nWESextremes = 956) and genome-wide genotypes (nGW = 9924, nGWextremes = 3308). We restricted our study to candidate genes known to harbour mutations for Mendelian small vessel disease: NOTCH3, HTRA1, COL4A1, COL4A2 and TREX1. We identified significant associations of a common intronic variant in HTRA1, rs2293871 using single variant association testing (Pdiscovery = 8.21 × 10-5, Preplication = 5.25 × 10-3, Pcombined = 4.72 × 10-5) and of NOTCH3 using gene-based tests (Pdiscovery = 1.61 × 10-2, Preplication = 3.99 × 10-2, Pcombined = 5.31 × 10-3). Follow-up analysis identified significant association of rs2293871 with small vessel ischaemic stroke, and two blood expression quantitative trait loci of HTRA1 in linkage disequilibrium. Additionally, we identified two participants in the 3C-Dijon cohort (0.4%) carrying heterozygote genotypes at known pathogenic variants for familial small vessel disease within NOTCH3 and HTRA1. In conclusion, our proof-of-concept study provides strong evidence that using a novel composite MRI-derived phenotype for extremes of small vessel disease can facilitate the identification of genetic variants underlying small vessel disease, both common variants and those with rare and low frequency. The findings demonstrate shared mechanisms and a continuum between genes underlying Mendelian small vessel disease and those contributing to the common, multifactorial form of the disease.


Assuntos
Doenças de Pequenos Vasos Cerebrais/genética , Serina Peptidase 1 de Requerimento de Alta Temperatura A/genética , Receptor Notch3/genética , Idoso , Idoso de 80 Anos ou mais , Isquemia Encefálica/genética , Doenças de Pequenos Vasos Cerebrais/diagnóstico por imagem , Doenças de Pequenos Vasos Cerebrais/metabolismo , Estudos de Coortes , Feminino , Heterozigoto , Serina Peptidase 1 de Requerimento de Alta Temperatura A/metabolismo , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Mutação , Polimorfismo de Nucleotídeo Único , Receptor Notch3/metabolismo , Receptor Notch3/fisiologia , Acidente Vascular Cerebral/genética , Substância Branca/diagnóstico por imagem , Substância Branca/metabolismo , Sequenciamento do Exoma/métodos
10.
BMC Psychiatry ; 18(1): 373, 2018 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-30482174

RESUMO

BACKGROUND: Suicidal ideation and suicidal risk assessment are major concerns for health professionals. The perception of a low level of parental support is a risk factor for suicidal tendencies among adolescents, but little is known about its long-term impact on the vulnerability to suicidal behavior in young adults. We investigated whether the perceived level of parental support during childhood and adolescence was associated with current suicidal ideation in young adults. METHODS: We retrieved data collected in the i-Share study from February 1st, 2013 through January 30, 2017. This cross-sectional study included 10,015 French students, aged 18-24 years that completed an on-line self-reported questionnaire about suicidal ideation in the last 12 months and their perceived parental support in childhood and adolescence. We performed multinomial logistic regressions and sensitivity analyses to assess associations between the degree of perceived parental support and the frequency suicidal thoughts, after adjusting for the main known risk factors of suicidal ideation. We employed multiple imputations to account for missing data. RESULTS: The study sample included 7539 female (75.7%) and 2436 male (24.3%) students (mean [SD] age 20.0 [1.8] years). About one in five students reported occasional suicidal thoughts (n = 1775, 17.7%) and 368 students (3.7%) reported frequent suicidal thoughts. The adjusted multinomial logistic regression revealed a significant negative association between perceived parental support and suicidal thoughts. A lack of perceived parental support in childhood and adolescence was associated with > 4-fold elevated risk of occasional (adjusted OR, 4.55; 95% CI: 2.97-6.99) and nearly 9-fold elevated risk of frequent (adjusted OR, 8.58; 95% CI: 4.62-15.96) suicidal thoughts, compared to individuals that perceived extremely strong parental support. This association was strongest among students with no personal history of depression or suicide attempts. CONCLUSIONS: Students that perceived low levels of past parental support had a higher risk of suicidal ideation. Past perceived parental support appeared to be a potent marker of suicidal risk in young adults. This marker should be routinely collected in studies on suicidal risk in young adults, and it could be considered an additional screening tool.


Assuntos
Relações Pais-Filho , Estudantes/psicologia , Ideação Suicida , Tentativa de Suicídio/estatística & dados numéricos , Adolescente , Adulto , Estudos Transversais , Depressão/psicologia , Feminino , Humanos , Internet , Modelos Logísticos , Masculino , Estudos Prospectivos , Fatores de Risco , Autorrelato , Inquéritos e Questionários , Adulto Jovem
11.
Stroke ; 49(2): 282-287, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29311265

RESUMO

BACKGROUND AND PURPOSE: The genetic contribution to dilated perivascular space (dPVS) burden-an emerging MRI marker of cerebral small vessel disease-is unknown. We measured the heritability of dPVS burden and its shared heritability with other MRI markers of cerebral small vessel disease. METHODS: The study sample comprised 1597 participants from the population-based Three City (3C) Dijon Study, with brain MRI and genome-wide genotyping (mean age, 72.8±4.1 years; 61% women). dPVS burden and lacunar brain infarcts were rated on a semiquantitative scale, whereas an automated algorithm generated white matter hyperintensity volume (WMHV). We estimated dPVS burden heritability and shared heritability with WMHV and lacunar brain infarcts using the genome-wide complex trait analysis tool, on unrelated participants, adjusting for age, sex, intracranial volume, and principal components of population stratification. RESULTS: dPVS burden was significantly correlated with WMHV and lacunar brain infarcts, the strongest correlation being found between WMHV and dPVS in basal ganglia. Heritability estimates were h2=0.59±0.24 (P=0.007) for dPVS burden, h2=0.54±0.24 (P=0.010) for WMHV, and h2=0.48±0.81 (P=0.278) for lacunar brain infarcts. We found a nonsignificant trend toward shared heritability between dPVS and WMHV (rg=0.41±0.28; P=0.096), which seemed driven by dPVS in basal ganglia (rg=0.72±0.61; P=0.126) and not dPVS in white matter (rg=-0.10±0.36; P=0.393). A genetic risk score for WMHV based on published loci was associated with increased dPVS burden in basal ganglia (P=0.031). CONCLUSIONS: We provide evidence for important genetic contribution to dPVS burden in older community-dwelling people, some of which may be shared with WMHV. Differential heritability patterns for dPVS in white matter and basal ganglia suggest at least partly distinct underlying biological processes.


Assuntos
Encéfalo/irrigação sanguínea , Doenças de Pequenos Vasos Cerebrais/genética , Acidente Vascular Cerebral Lacunar/genética , Idoso , Idoso de 80 Anos ou mais , Doenças de Pequenos Vasos Cerebrais/complicações , Feminino , Genótipo , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Fatores de Risco , Acidente Vascular Cerebral Lacunar/complicações
12.
Ann Rheum Dis ; 77(3): 328-335, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-28754803

RESUMO

OBJECTIVES: In patients with gout, maintaining too low serum uric acid (SUA) level with urate-lowering therapy is a concern because uric acid is thought to be neuroprotective. However, the relation between SUA and dementia remains debated. This study aimed to investigate the impact of SUA level on the incidence of dementia. METHODS: We assessed the longitudinal association between SUA level and incident dementia (Diagnostic and Statistical Manual of Mental Disorders Version IV (DSM-IV) criteria) in a large cohort of healthy older people from the community (Three-City Dijon cohort). Additionally, we investigated the relation between SUA level and MRI markers of brain ageing (white matter hyperintensity volume (WMHV), lacunes and hippocampal volume). RESULTS: The study sample comprised 1598 people (mean (SD) age 72.4(4.1) years, 38.3% male). During the 13,357 person-years of follow-up (median duration: 10.1 years), dementia developed in 110 participants (crude incidence rate: 8.2/1000 person-years). After multiple adjustments, the multivariate HR with the highest (≥75th percentile) versus lowest SUA level was 1.79 (95% CI 1.17 to 2.73; p=0.007). The association was stronger with vascular or mixed dementia (HR=3.66 (95% CI 1.29 to 10.41), p=0.015) than Alzheimer's disease (HR=1.55 (95% CI 0.92 to 2.61), p=0.10). There was a non-significant trend towards an association between high SUA level and extensive WMHV (p=0.10), a biomarker of small vessel disease, but not hippocampal volume (p=0.94) or lacunes (p=0.86). The association between SUA level and vascular or mixed dementia might be affected by interim strokes. CONCLUSIONS: Risk of dementia, especially vascular or mixed dementia, may be increased with high SUA levels in elderly people.


Assuntos
Demência/sangue , Gota/sangue , Ácido Úrico/sangue , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/sangue , Biomarcadores/sangue , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Estudos de Coortes , Demência/epidemiologia , Demência/etiologia , Feminino , Seguimentos , França/epidemiologia , Gota/complicações , Humanos , Incidência , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Fatores de Risco , Sensibilidade e Especificidade
14.
Hypertension ; 70(1): 44-49, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28559394

RESUMO

Several studies indicate a potential link between orthostatic hypotension (OH) and incident dementia but without substantial evidence to date. Our objective is to study the association between OH and dementia in a cohort of elderly individuals. To do so, baseline lying and standing blood pressure measurements were taken from 7425 subjects in the Three-City study. These subjects were then followed-up for 12 years. Cox proportional hazard models, adjusted for potential confounders, were used to estimate the risk of incident dementia according to OH status. Sensitivity analysis was performed using the so-called illness-death model, a specific statistical method which takes into account competitive risk with death. OH frequency was found to be around 13%, and 760 cases of dementia were diagnosed during follow-up. We observed significant associations between the presence of OH at baseline and the occurrence of dementia during the follow-up, with an increased risk of at least 25% observed regardless of the OH threshold and the statistical method used. In conclusion, there is an association between OH and dementia. Considering that OH is a common condition and is easy to measure, OH measurements could help to identify subjects with higher risk of dementia. Moreover, reducing OH could be a step to prevent conversion to dementia.


Assuntos
Demência , Hipotensão Ortostática , Medição de Risco , Idoso , Determinação da Pressão Arterial/métodos , Demência/diagnóstico , Demência/epidemiologia , Feminino , Seguimentos , França/epidemiologia , Avaliação Geriátrica/métodos , Humanos , Hipotensão Ortostática/diagnóstico , Hipotensão Ortostática/epidemiologia , Vida Independente/estatística & dados numéricos , Testes de Inteligência/estatística & dados numéricos , Masculino , Prevalência , Modelos de Riscos Proporcionais , Medição de Risco/métodos , Medição de Risco/estatística & dados numéricos , Fatores de Risco
15.
PLoS Med ; 14(3): e1002265, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28350817

RESUMO

BACKGROUND: Vascular risk factors have been proposed as important targets for the prevention of dementia. As lipid fractions represent easily modifiable targets, we examined the longitudinal relationship of baseline lipid fractions with 13-y incident dementia and its subtypes (Alzheimer disease [AD] and mixed or vascular dementia) in older community-dwelling persons. METHODS AND FINDINGS: Non-institutionalized persons aged 65+ y (n = 9,294) were recruited for the Three-City Study (3C Study), a population-based cohort study from the electoral rolls of the cities of Dijon, Bordeaux, and Montpellier, France, between March 1999 and March 2001. Follow-up examinations were performed every 2 y after the baseline assessment. The final study sample comprised 7,470 participants from the 3C Study (mean age ± standard deviation [SD] 73.8 ± 5.3 y, 61.0% women) who were prospectively followed up for up to 13 y. Fasting lipid fractions (triglycerides [TGs], high-density lipoprotein cholesterol [HDL-C], low-density lipoprotein cholesterol [LDL-C], total cholesterol [TC]) were studied as continuous variables, and results are reported per SD increase of each lipid fraction. Incident dementia and its subtypes were studied as censored variables using Cox models with age as time scale. Analyses were adjusted for sex, study center, and educational level, as well as vascular risk factors and apolipoprotein E (APOE) ε4 genotype. We corrected for multiple testing, yielding a significance threshold of 0.0169. p-Values above the significance threshold but less than 0.05 were considered nominally significant. During a mean (± SD) follow-up period of 7.9 ± 3.6 y, 779 participants developed incident dementia (n = 532 AD and n = 154 mixed or vascular dementia). Higher LDL-C and TC concentrations at baseline were associated with an increased risk of AD (hazard ratio [HR] per SD increase = 1.13 [95% CI 1.04-1.22], p = 0.0045, and HR = 1.12 [1.03-1.22], p = 0.0072, respectively). These associations were largely unchanged after adjustment for vascular risk factors and were attenuated after adjustment for APOEε4 (HR per SD increase = 1.12 [1.03-1.23], p = 0.0110, and HR = 1.12 [1.02-1.23], p = 0.0171, respectively). Higher TG concentrations at baseline were associated with an increased risk of all dementia (HR per SD increase = 1.11 [1.03-1.19], p = 0.0044) and mixed or vascular dementia (HR = 1.21 [1.04-1.41], p = 0.0163). However, these associations disappeared after adjusting for vascular risk factors (HR = 1.07 [0.98-1.17], p = 0.1374, and HR = 1.17 [0.96-1.42], p = 0.1206, respectively). Main limitations of the study include interval censoring of incident dementia cases, potential selective survival bias, and the fact that variation in lipid concentrations during follow-up could not be accounted for in the analyses. CONCLUSIONS: In a large population-based sample of older community-dwelling persons with up to 13 y of follow-up, we observed that higher LDL-C and TC concentrations were associated with an increased risk of AD. This result was independent of vascular risk factors and was attenuated after adjustment for APOEε4 carrier status. TG and HDL-C concentrations were not associated with risk of incident dementia or its subtypes after accounting for vascular risk factors.


Assuntos
Colesterol/sangue , Demência/epidemiologia , Triglicerídeos/sangue , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/sangue , Doença de Alzheimer/epidemiologia , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Demência/sangue , Demência Vascular/sangue , Demência Vascular/epidemiologia , Feminino , França/epidemiologia , Humanos , Incidência , Estudos Longitudinais , Masculino , Estudos Prospectivos , Fatores de Risco
16.
J Hypertens ; 35(3): 612-620, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27984412

RESUMO

OBJECTIVE: Home blood pressure (BP) monitoring is one of the tools recommended in hypertension management. However, its influence in older adults is seldom investigated. We aimed to assess whether regular home BP monitoring leads to a reduction of BP and an improvement in hypertension control in older adults. METHODS: In a 24-month trial, individuals aged 73-97 years were randomized in a control (office and home BP measured at 0, 12, and 24 months) or an intervention (office measured at 0, 12, and 24 months; home BP measured every 3 months) group. The primary outcome was the difference in means office BP over 24 months in hypertensive patients. Secondary outcomes included differences in mean home BP over follow-up in hypertensive patients, and frequency of hypertension and of drug use at 24 months in the total sample. Intention-to-treat analyses comprised 1733 persons, among which 1043 were hypertensive. RESULTS: Hypertensive patients in the intervention group experienced a significantly greater fall in office systolic BP (SBP) [mean between-group difference -2.1 mmHg, 95% confidence interval (CI) -4.1; -0.2, P = 0.03], home SBP (mean between-group difference -3.4, 95% CI -4.8; -2.1, P < 0.0001), and home diastolic BP (mean between-group difference -1.1, 95% CI -1.8; -0.4, P = 0.002) than those in the control group, in the main model. No overall differences were observed for office diastolic BP (P = 0.74), frequency of hypertension (P = 0.92), or drug use (P = 0.51) over time. Similar results were observed after adjustment for known predictors of BP though attenuated for office SBP (P = 0.07). CONCLUSION: Regular home BP monitoring every 3 months without co-intervention results in small but greater reductions of BP over time. Further research in large trials focused on older adults is needed to confirm the effectiveness of this intervention in a variety of settings.


Assuntos
Monitorização Ambulatorial da Pressão Arterial , Pressão Sanguínea , Hipertensão/fisiopatologia , Visita a Consultório Médico , Idoso , Idoso de 80 Anos ou mais , Diástole , Feminino , França , Humanos , Masculino , Autocuidado , Sístole
17.
Stroke ; 47(11): 2865-2869, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27659853

RESUMO

BACKGROUND AND PURPOSE: White matter hyperintensity (WMH) volume and covert brain infarcts are highly prevalent in older adults and are often asymptomatic. We compared the impact of WMH volume and brain infarcts on risk of clinical stroke and dementia in older adults in the population. METHODS: Participants were 1677 individuals aged ≥65 years from the 3-City Dijon study, who were free of stroke and dementia at baseline, followed-up for ≤12 years. RESULTS: Both lesion types were comparably associated with an increased risk of stroke (adjusted hazard ratio, 1.72; 95% confidence interval, 1.24-2.40 for WMH volume and hazard ratio, 2.15; 95% confidence interval, 1.18-3.93 for brain infarcts), but only WMH volume was associated with an increased risk of dementia (hazard ratio, 1.41; 95% confidence interval, 1.09-1.83). CONCLUSIONS: The differential impact of WMH and brain infarcts on clinical stroke and dementia suggests relatively different prognostic value of the 2 lesions. WMHs may represent a particularly pertinent magnetic resonance imaging intermediate marker that can be utilized in optimizing prevention strategies for both stroke and dementia in primary care and in trials.


Assuntos
Infarto Encefálico/diagnóstico por imagem , Infarto Encefálico/epidemiologia , Demência/epidemiologia , Leucoaraiose/diagnóstico por imagem , Leucoaraiose/epidemiologia , Acidente Vascular Cerebral/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Comorbidade , Feminino , Seguimentos , França/epidemiologia , Humanos , Imageamento por Ressonância Magnética , Masculino
18.
J Am Coll Cardiol ; 68(9): 934-45, 2016 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-27561768

RESUMO

BACKGROUND: Epidemiological studies show that high circulating cystatin C is associated with risk of cardiovascular disease (CVD), independent of creatinine-based renal function measurements. It is unclear whether this relationship is causal, arises from residual confounding, and/or is a consequence of reverse causation. OBJECTIVES: The aim of this study was to use Mendelian randomization to investigate whether cystatin C is causally related to CVD in the general population. METHODS: We incorporated participant data from 16 prospective cohorts (n = 76,481) with 37,126 measures of cystatin C and added genetic data from 43 studies (n = 252,216) with 63,292 CVD events. We used the common variant rs911119 in CST3 as an instrumental variable to investigate the causal role of cystatin C in CVD, including coronary heart disease, ischemic stroke, and heart failure. RESULTS: Cystatin C concentrations were associated with CVD risk after adjusting for age, sex, and traditional risk factors (relative risk: 1.82 per doubling of cystatin C; 95% confidence interval [CI]: 1.56 to 2.13; p = 2.12 × 10(-14)). The minor allele of rs911119 was associated with decreased serum cystatin C (6.13% per allele; 95% CI: 5.75 to 6.50; p = 5.95 × 10(-211)), explaining 2.8% of the observed variation in cystatin C. Mendelian randomization analysis did not provide evidence for a causal role of cystatin C, with a causal relative risk for CVD of 1.00 per doubling cystatin C (95% CI: 0.82 to 1.22; p = 0.994), which was statistically different from the observational estimate (p = 1.6 × 10(-5)). A causal effect of cystatin C was not detected for any individual component of CVD. CONCLUSIONS: Mendelian randomization analyses did not support a causal role of cystatin C in the etiology of CVD. As such, therapeutics targeted at lowering circulating cystatin C are unlikely to be effective in preventing CVD.


Assuntos
Doenças Cardiovasculares/genética , Cistatina C/genética , Análise da Randomização Mendeliana/métodos , Polimorfismo de Nucleotídeo Único , Idoso , Alelos , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/epidemiologia , Cistatina C/sangue , Genótipo , Saúde Global , Humanos , Incidência , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco
19.
Neurobiol Aging ; 36(10): 2663-70, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26242707

RESUMO

Cerebral ß-amyloid (Aß) deposition and atrophy are central features of Alzheimer disease. Studies of Alzheimer disease biomarkers have largely focused on Aß in cerebrospinal fluid (CSF), and there is uncertainty as to what plasma Aß may be a marker. We examined the association of Aß levels in the plasma with magnetic resonance imaging (MRI)-markers of brain aging, including longitudinal changes in global and regional brain volumes, in dementia-free persons. We studied 1530 participants of the Three-City-Dijon cohort, aged 65-80 years. Plasma Aß measurement and magnetic resonance imaging were performed at baseline and after a 4-year follow up. Total brain, gray matter, and hippocampal volume were estimated using voxel-based morphometry, and annualized change in brain volumes was calculated. Increased plasma Aß1-40 was associated with lower baseline hippocampal volume. Although baseline plasma Aß levels were not associated with longitudinal change in brain volumes, consistently high plasma Aß1-40 levels were associated with faster total brain atrophy and consistently low plasma Aß1-42/Aß1-40 ratio, with increased total brain atrophy and gray matter atrophy. In dementia-free older adults, high plasma Aß1-40 and low plasma Aß1-42/Aß1-40 ratio were associated with smaller hippocampal volume and accelerated global and regional brain atrophy respectively.


Assuntos
Envelhecimento/sangue , Envelhecimento/patologia , Doença de Alzheimer/diagnóstico , Peptídeos beta-Amiloides/sangue , Encéfalo/patologia , Imageamento por Ressonância Magnética , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/sangue , Doença de Alzheimer/etiologia , Doença de Alzheimer/patologia , Biomarcadores/sangue , Feminino , Seguimentos , Hipocampo/patologia , Humanos , Masculino , Tamanho do Órgão , Fragmentos de Peptídeos/sangue
20.
BMJ Open ; 4(11): e005938, 2014 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-25421338

RESUMO

OBJECTIVE: To evaluate the association between white matter lesion (WML) volume, silent infarcts and restless legs syndrome (RLS) in a population-based study of elderly individuals. DESIGN: Cross-sectional study. SETTING: Population-based Three-City study. PARTICIPANTS: 1035 individuals from the Dijon, France, centre of the Three-City study who had available information on volume of WMLs from MRIs and who answered questions about the prevalence of RLS. PRIMARY OUTCOME MEASURE: Prevalence of RLS. RESULTS: WML volume was measured using an automated tissue segmentation method. Logistic regression was used to evaluate adjusted associations between tertiles of WML volume and RLS and between silent infarcts and RLS. 218 individuals (21.1%) were determined to have RLS. Compared with those in the first tertile of WML volume, individuals in the second tertile (OR=1.09; 95% CI 0.75 to 1.60) or third tertile (OR=1.17; 95% CI 0.79 to 1.74) did not have an increased prevalence of RLS. We also did not observe associations between the volume of deep or periventricular WML and RLS; nor did we observe an association between silent brain infarcts and RLS (OR=0.74; 95% CI 0.40 to 1.39). These findings were not modified by age or gender. CONCLUSIONS: Higher volume of WML and the presence of silent infarcts were not associated with an increased prevalence of RLS in this population-based cohort of elderly individuals.


Assuntos
Leucoencefalopatias/complicações , Leucoencefalopatias/patologia , Síndrome das Pernas Inquietas/complicações , Síndrome das Pernas Inquietas/epidemiologia , Idoso , Estudos de Coortes , Estudos Transversais , Feminino , Humanos , Estudos Longitudinais , Masculino , Tamanho do Órgão , Prevalência
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