Alexa Beiser

University of California, Davis, Davis, California, United States

Are you Alexa Beiser?

Claim your profile

Publications (181)1740.65 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Introduction: This study examined whether interarm differences in systolic blood pressure (IDSBP) ≥10 mm Hg were associated with the risk of incident dementia and subclinical brain injury. Methods: Between 1992 and 1998, 2063 participants of the Framingham Heart Study underwent assessment of IDSBP with results related to the 10-year risk of incident dementia including clinically characterized Alzheimer's disease. Secondary outcomes included markers of subclinical brain injury on magnetic resonance imaging. Results: High IDSBP were associated with a greater risk of incident dementia (hazard ratio [HR] 1.92; 95% confidence interval [CI], 1.09-3.40) and Alzheimer's disease (HR, 2.32; 95% CI, 1.29-4.18), but only in those who carried an APOE ε4 allele. IDSBP also predicted lower total brain volumes and more prevalent silent brain infarcts in those who were APOE ε4 positive. Discussion: High IDSBP were associated with an increased risk of dementia, including clinical Alzheimer's disease, and subclinical brain injury in those who were APOE ε4 positive.
    Alzheimer's & dementia: the journal of the Alzheimer's Association 11/2015; DOI:10.1016/j.jalz.2015.09.006 · 12.41 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective: To understand the neuropsychological basis of dementia risk among persons in the spectrum including cognitive normality and mild cognitive impairment. Methods: We quantitated risk of progression to dementia in elderly persons without dementia from 2 population-based studies, the Framingham Heart Study (FHS) and Mayo Clinic Study of Aging (MCSA), aged 70 to 89 years at enrollment. Baseline cognitive status was defined by performance in 4 domains derived from batteries of neuropsychological tests (that were similar but not identical for FHS and MCSA) at cut scores corresponding to SDs of ≤-0.5, -1, -1.5, and -2 from normative means. Participants were characterized as having no cognitive impairment (reference group), or single or multiple amnestic or nonamnestic profiles at each cut score. Incident dementia over the following 6 years was determined by consensus committee at each study separately. Results: The pattern of hazard ratios for incident dementia, rates of incident dementia and positive predictive values across cognitive test cut scores, and number of affected domains was similar although not identical across the FHS and MCSA. Dementia risks were higher for amnestic profiles than for nonamnestic profiles, and for multidomain compared with single-domain profiles. Conclusions: Cognitive domain subtypes, defined by neuropsychologically derived cut scores and number of low-performing domains, differ substantially in prognosis in a conceptually logical manner that was consistent between FHS and MCSA. Neuropsychological characterization of elderly persons without dementia provides valuable information about prognosis. The heterogeneity of risk of dementia cannot be captured concisely with one test or a single definition or cutpoint.
    Neurology 10/2015; DOI:10.1212/WNL.0000000000002100 · 8.29 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background and purpose: White matter lesion (WML) progression on magnetic resonance imaging is related to cognitive decline and stroke, but its determinants besides baseline WML burden are largely unknown. Here, we estimated heritability of WML progression, and sought common genetic variants associated with WML progression in elderly participants from the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium. Methods: Heritability of WML progression was calculated in the Framingham Heart Study. The genome-wide association study included 7773 elderly participants from 10 cohorts. To assess the relative contribution of genetic factors to progression of WML, we compared in 7 cohorts risk models including demographics, vascular risk factors plus single-nucleotide polymorphisms that have been shown to be associated cross-sectionally with WML in the current and previous association studies. Results: A total of 1085 subjects showed WML progression. The heritability estimate for WML progression was low at 6.5%, and no single-nucleotide polymorphisms achieved genome-wide significance (P<5×10(-8)). Four loci were suggestive (P<1×10(-5)) of an association with WML progression: 10q24.32 (rs10883817, P=1.46×10(-6)); 12q13.13 (rs4761974, P=8.71×10(-7)); 20p12.1 (rs6135309, P=3.69×10(-6)); and 4p15.31 (rs7664442, P=2.26×10(-6)). Variants that have been previously related to WML explained only 0.8% to 11.7% more of the variance in WML progression than age, vascular risk factors, and baseline WML burden. Conclusions: Common genetic factors contribute little to the progression of age-related WML in middle-aged and older adults. Future research on determinants of WML progression should focus more on environmental, lifestyle, or host-related biological factors.
    Stroke 10/2015; DOI:10.1161/STROKEAHA.115.009252 · 5.72 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Leptin is a major adipokine that regulates weight balance and energy homeostasis. There is inconsistent evidence linking circulating leptin levels to risk of stroke. We tested the hypothesis that leptin levels are associated with risk of incident stroke in an elderly community based sample. Serum leptin levels were assayed in 757 strokefree individuals (mean age, 79 years; 62% women) from the Framingham Original Cohort at the 22nd examination cycle (1990-1994). Incidence of all-stroke and ischemic stroke were prospectively ascertained. During a mean followup of 10 years, 119 individuals developed stroke (99 ischemic strokes). In multivariable Cox regression models, logleptin levels were not associated with incidence of all-stroke or ischemic stroke (hazard ratios per SD increment in logleptin 0.90 [0.73-1.09] and 0.89 [0.72-1.11], respectively). The results were suggestive for potential effect modification by waist/hip ratio for the association between leptin and stroke (P=0.03). Adjusting for age, sex, and established stroke risk factors, analysis stratified by waist/hip ratio quartiles revealed a lower incidence of first-ever all-stroke and ischemic stroke associated with higher leptin levels among only subjects in the top waist/hip ratio quartile (hazard ratio, 0.64 [0.43, 0.95] versus 0.98 [0.77, 1.25] for incident all-stroke and 0.61 [0.39, 0.95] versus 0.96 [0.74, 1.26] for ischemic stroke). Leptin levels were not directly related to the risk of incident stroke overall but there was an inverse association with stroke in the top waist/hip ratio quartile. Further investigations are required to confirm these findings and explore possible mechanisms for the observed association. © 2015 American Heart Association, Inc.
    Stroke 09/2015; 46(10). DOI:10.1161/STROKEAHA.115.009463 · 5.72 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Growth differentiation factor-15 (GDF-15) and soluble (s)ST2 are markers of cardiac and vascular stress. We investigated the associations between circulating concentrations of these biomarkers and incident stroke and subclinical vascular brain injury in a sample from the Framingham Offspring cohort. We followed 3374 stroke- and dementia-free individuals (mean age, 59.0±9.7 years; 53% women) attending the Framingham Offspring sixth examination cycle 11.8±3.0 years for incident stroke. A subsample of 2463 individuals underwent brain magnetic resonance imaging and neuropsychological testing ≈4.0±1.7 years after the sixth examination. After adjustment for traditional cardiovascular risk factors, B-type natriuretic peptide, high-sensitivity C-reactive protein, and urine albumin levels, higher stress biomarker levels were associated cross-sectionally with lower brain volumes (β coefficients for intracranial volume comparing fourth [Q4] versus first biomarker [Q1] quartiles: -0.71% for GDF-15; P=0.002 and 0.47% for sST2; P=0.02) and worse performance on the visual reproduction test (β coefficients for Q4 versus Q1: -0.62 for GDF-15; P=0.009 and -0.40 for sST2; P=0.04). Higher GDF-15 concentrations were also associated with greater log-transformed white-matter hyperintensity volumes (β for Q4 versus Q1=0.19; P=0.01). Prospectively, a total of 203 (6%) individuals developed incident stroke/transient ischemic attack during follow-up. After multivariable adjustment, sST2 remained significantly associated with stroke/transient ischemic attack, hazard ratio for Q4 versus Q1 of 1.76, 95% confidence interval of 1.06 to 2.92, and P=0.03. Circulating GDF-15 and sST2 are associated with subclinical brain injury and cognitive impairment. Higher sST2 concentrations are also associated with incident stroke, suggesting potential links between cardiac stress biomarkers and brain injury. © 2015 American Heart Association, Inc.
    Stroke 07/2015; 46(9). DOI:10.1161/STROKEAHA.115.009026 · 5.72 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Midlife cardiovascular risk, hypertension (HTN) in particular, has been related cross-sectionally to poorer neuropsychological (NP) performance in middle age and older adults. This study investigated whether a similar relationship persists between midlife HTN or systolic blood pressure (SBP) and NP performance approximately 30 years later. 378 Framingham stroke and dementia-free Original cohort participants, with HTN and SBP ascertained between 50-60 years of age (mean age 55 ± 1, 65% women), were administered a NP assessment at age ≥80 years. Tests included Logical Memory, Visual Reproduction, Paired Associate, Hooper Visual Organization Test, Trail Making A & B, Digit Span Forward and Backward, Controlled Word Association Test (COWAT), and Similarities. Multivariable linear regression, adjusted for age, time interval between risk factor and NP testing, gender, and premorbid intelligence, assessed association between midlife HTN/SBP and NP outcomes. Midlife HTN was not significantly associated with NP outcome measures. Midlife SBP was associated with poorer Digit Span Forward and COWAT performance (p < 0.05). No significant interaction of age on HTN/SBP to NP associations was found. There was a significant interaction between ApoE4 status and SBP in their effects on COWAT (pinteraction = 0.074); SBP was negatively associated with COWAT only in those with the ApoE4 allele (p = 0.025). While midlife HTN is not associated with late life cognitive impairment, midlife SBP is related to late life attention and verbal fluency impairments, particularly among ApoE4+ individuals. These results offer insight into processes that are operative in the absence of overt cognitive impairment and dementia.
    Journal of Alzheimer's disease: JAD 07/2015; 47(1):197-204. DOI:10.3233/JAD-141881 · 4.15 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background/Study Context: The number of individuals who reach extreme age is quickly increasing. Much of the current literature focuses on impaired cognition in extreme age, and debate continues regarding what constitutes "normal" cognition in extreme age. This study aimed to provide oldest-old normative data and to compare cognitive performances of cognitively intact elderly individuals from the Framingham Heart Study. A total of 1302 individuals aged 65+ years from the Framingham Heart Study were separated into 5-year age bands and compared on cognitive tests. Multivariate linear regression analyses were conducted, adjusting for gender, the Wide Range Achievement Test-Third Edition (WRAT-III) Reading score, and cohort. Analyses also included comparisons between 418 individuals aged 80+ and 884 individuals aged 65-79, and comparisons within oldest-old age bands. Normative data for all participants are presented. Significant differences were found on most tests between age groups in the overall analysis between young-old and oldest-old, and analysis of oldest-old age bands also revealed select significant differences (all ps <.05). As aging increases, significant cognitive differences and increased variability in performances are evident. These results support the use of age-appropriate normative data for oldest-old individuals.
    Experimental Aging Research 07/2015; 41(4):386-409. DOI:10.1080/0361073X.2015.1053755 · 0.92 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The Boston criteria are the basis for a noninvasive diagnosis of cerebral amyloid angiopathy (CAA) in the setting of lobar intracerebral hemorrhage (ICH). We assessed the accuracy of these criteria in individuals with lobar microbleeds (MBs) without ICH. We identified individuals aged >55 years having brain magnetic resonance imaging (MRI) and pathologic assessment of CAA in a single academic hospital and a community-based population (Framingham Heart Study [FHS]). We determined the positive predictive value (PPV) of the Boston criteria for CAA in both cohorts, using lobar MBs as the only hemorrhagic lesion to fulfill the criteria. We included 102 individuals: 55 from the hospital-based cohort and 47 from FHS (mean age at MRI 74.7 ± 8.5 and 83.4 ± 10.9 years; CAA prevalence 60% and 46.8%; cases with any lobar MB 49% and 21.3%; and cases with ≥2 strictly lobar MBs 29.1% and 8.5%, respectively). PPV of "probable CAA" (≥2 strictly lobar MBs) was 87.5 (95% confidence interval [CI], 60.4-97.8) and 25 (95% CI, 13.2-78) in hospital and general populations, respectively. Strictly lobar MBs strongly predict CAA in non-ICH individuals when found in a hospital context. However, their diagnostic accuracy in the general population appears limited. Copyright © 2015 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.
    Alzheimer's & dementia: the journal of the Alzheimer's Association 06/2015; 128. DOI:10.1016/j.jalz.2015.04.009 · 12.41 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Comprehensive long-term data on atrial fibrillation trends in men and women are scant. We aimed to provide such data through analysis of the Framingham cohort over 50 years. We investigated trends in incidence, prevalence, and risk factors for atrial fibrillation and its association with stroke and mortality after onset in 9511 participants enrolled in the Framingham Heart Study between 1958 and 2007. We analysed trends within 10 year groups (1958-67, 1968-77, 1978-87, 1988-97, and 1998-2007), stratified by sex. During 50 years of observation (202 417 person-years), 1544 cases of new-onset atrial fibrillation occurred (of whom 723 [47%] were women). Between 1958-67 and 1998-2007, age-adjusted prevalence of atrial fibrillation quadrupled from 20·4 to 96·2 cases per 1000 person-years in men and from 13·7 to 49·4 cases per 1000 person-years in women; age-adjusted incidence increased from 3·7 to 13·4 new cases per 1000 person-years in men and from 2·5 to 8·6 new cases per 1000 person-years in women (ptrend<0·0001 for all comparisons). For atrial fibrillation diagnosed by electrocardiograph (ECG) during routine Framingham examinations, age-adjusted prevalence per 1000 person-years increased (12·6 in 1958-67 to 25·7 in 1998-2007 in men, ptrend=0·0007; 8·1 to 11·8 in women, ptrend=0·009). However, age-adjusted incidence of atrial fibrillation by Framingham Heart Study ECGs did not change significantly with time. Although the prevalence of most risk factors changed over time, their associated hazards for atrial fibrillation changed little. Multivariable-adjusted proportional hazards models revealed a 74% (95% CI 50-86%) decrease in stroke (hazards ratio [HR] 3·77, 95% CI 1·98-7·20 in 1958-1967 compared with 1998-2007; ptrend=0·0001) and a 25% (95% CI -3-46%) decrease in mortality (HR 1·34, 95% CI 0·97-1·86 in 1958-1967 compared with 1998-2007; ptrend=0·003) in 20 years following atrial fibrillation onset. Trends of increased incidence and prevalence of atrial fibrillation in the community were probably partly due to enhanced surveillance. Measures are needed to enhance early detection of atrial fibrillation, through increased awareness coupled with targeted screening programmes and risk factor-specific prevention. NIH, NHLBI, NINDS, Deutsche Forschungsgemeinschaft. Copyright © 2015 Elsevier Ltd. All rights reserved.
    The Lancet 05/2015; 386(9989). DOI:10.1016/S0140-6736(14)61774-8 · 45.22 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To evaluate the possible early consequences of impaired glucose metabolism on the brain by assessing the relationship of diabetes, fasting blood glucose (FBG) levels, and insulin resistance with cognitive performance and brain integrity in healthy young and middle-aged adults. The sample included dementia-free participants (mean age 40 ± 9 years; 53% women) of the Framingham Heart Study third-generation cohort with cognitive testing of memory, abstract reasoning, visual perception, attention, and executive function (n = 2,126). In addition, brain MRI examination (n = 1,597) was used to determine white matter, gray matter, and white matter hyperintensity (WMH) volumes and fractional anisotropy measures. We used linear regression models to assess relationships between diabetes, FBG, and insulin resistance with cognition, lobar gray matter, and WMH volumes as well as voxel-based microstructural white matter integrity and gray matter density, adjusting for potential confounders. Mediating effect of brain lesions on the association of diabetes with cognitive performance was also tested. Diabetes was associated with worse memory, visual perception, and attention performance; increased WMH; and decreased total cerebral brain and occipital lobar gray matter volumes. The link of diabetes with attention and memory was mediated through occipital and frontal atrophy, and the latter also through hippocampal atrophy. Both diabetes and increased FBG were associated with large areas of reductions in gray matter density and fractional anisotropy on voxel-based analyses. We found that hyperglycemia is associated with subtle brain injury and impaired attention and memory even in young adults, indicating that brain injury is an early manifestation of impaired glucose metabolism. © 2015 American Academy of Neurology.
    Neurology 05/2015; 84(23). DOI:10.1212/WNL.0000000000001655 · 8.29 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Long-term exposure to ambient air pollution is associated with cerebrovascular disease and cognitive impairment, but whether it is related to structural changes in the brain is not clear. We examined the associations between residential long-term exposure to ambient air pollution and markers of brain aging using magnetic resonance imaging. Framingham Offspring Study participants who attended the seventh examination were at least 60 years old and free of dementia and stroke were included. We evaluated associations between exposures (fine particulate matter [PM2.5] and residential proximity to major roadways) and measures of total cerebral brain volume, hippocampal volume, white matter hyperintensity volume (log-transformed and extensive white matter hyperintensity volume for age), and covert brain infarcts. Models were adjusted for age, clinical covariates, indicators of socioeconomic position, and temporal trends. A 2-μg/m(3) increase in PM2.5 was associated with -0.32% (95% confidence interval, -0.59 to -0.05) smaller total cerebral brain volume and 1.46 (95% confidence interval, 1.10 to 1.94) higher odds of covert brain infarcts. Living further away from a major roadway was associated with 0.10 (95% confidence interval, 0.01 to 0.19) greater log-transformed white matter hyperintensity volume for an interquartile range difference in distance, but no clear pattern of association was observed for extensive white matter. Exposure to elevated levels of PM2.5 was associated with smaller total cerebral brain volume, a marker of age-associated brain atrophy, and with higher odds of covert brain infarcts. These findings suggest that air pollution is associated with insidious effects on structural brain aging even in dementia- and stroke-free persons. © 2015 American Heart Association, Inc.
    Stroke 04/2015; 46(5). DOI:10.1161/STROKEAHA.114.008348 · 5.72 Impact Factor
  • Source

    Molecular Psychiatry 04/2015; · 14.50 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: To identify common variants contributing to normal variation in two specific domains of cognitive functioning, we conducted a genome-wide association study (GWAS) of executive functioning and information processing speed in non-demented older adults from the CHARGE (Cohorts for Heart and Aging Research in Genomic Epidemiology) consortium. Neuropsychological testing was available for 5429-32 070 subjects of European ancestry aged 45 years or older, free of dementia and clinical stroke at the time of cognitive testing from 20 cohorts in the discovery phase. We analyzed performance on the Trail Making Test parts A and B, the Letter Digit Substitution Test (LDST), the Digit Symbol Substitution Task (DSST), semantic and phonemic fluency tests, and the Stroop Color and Word Test. Replication was sought in 1311-21860 subjects from 20 independent cohorts. A significant association was observed in the discovery cohorts for the single-nucleotide polymorphism (SNP) rs17518584 (discovery P-value=3.12 × 10(-8)) and in the joint discovery and replication meta-analysis (P-value=3.28 × 10(-9) after adjustment for age, gender and education) in an intron of the gene cell adhesion molecule 2 (CADM2) for performance on the LDST/DSST. Rs17518584 is located about 170 kb upstream of the transcription start site of the major transcript for the CADM2 gene, but is within an intron of a variant transcript that includes an alternative first exon. The variant is associated with expression of CADM2 in the cingulate cortex (P-value=4 × 10(-4)). The protein encoded by CADM2 is involved in glutamate signaling (P-value=7.22 × 10(-15)), gamma-aminobutyric acid (GABA) transport (P-value=1.36 × 10(-11)) and neuron cell-cell adhesion (P-value=1.48 × 10(-13)). Our findings suggest that genetic variation in the CADM2 gene is associated with individual differences in information processing speed.Molecular Psychiatry advance online publication, 14 April 2015; doi:10.1038/mp.2015.37.
    Molecular Psychiatry 04/2015; DOI:10.1038/mp.2015.37 · 14.50 Impact Factor

  • Nature 04/2015; 520(7545):E2-E3. DOI:10.1038/nature14038 · 41.46 Impact Factor
  • W Agbenyikey · R Karasek · M Cifuentes · P A Wolf · S Seshadri · J A Taylor · A S Beiser · R Au ·
    [Show abstract] [Hide abstract]
    ABSTRACT: Workplace stress is known to be related with many behavioral and disease outcomes. However, little is known about its prospective relationship with measures of cognitive decline. To investigate the association of job strain, psychological demands and job control on cognitive decline. Participants from Framingham Offspring cohort (n=1429), were assessed on job strain, and received neuropsychological assessment approximately 15 years and 21 years afterwards. High job strain and low control were associated with decline in verbal learning and memory. Job strain was associated with decline in word recognition skills. Active job and passive job predicted decline in verbal learning and memory relative to low strain jobs in the younger subgroup. Active job and demands were positively associated with abstract reasoning skills. Job strain and job control may influence decline in cognitive performance.
    International Journal of Occupational and Environmental Medicine 04/2015; 6(2):79-94.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Analysis sought to determine whether Wechsler Memory Scale-Logical Memory (LM)-correct responses and errors were related to magnetic resonance imaging (MRI) brain volume measurements. The LM immediate (LM-I) and LM delay (LM-D) free recall correct responses and related and unrelated errors were scored. Principal components analysis yielded a 3-factor solution: LM-I and LM-D correct responses, LM-I and LM-D-unrelated errors, and LM-I/-D-related errors. The MRI total cerebral brain volume, frontal brain volume, temporal horn volume (THV), and white matter hyperintensities volume (WMHIV) were obtained. Increasing THV (suggesting greater regional atrophy) was associated with lower scores on the LM-correct responses factor. Extensive WMHIV was associated with higher scores on the LM-related errors factor. These results suggest that LM-correct responses could relate to emerging brain alterations. Longitudinal research might enhance the sensitivity of this test to identify preclinical impairment and persons at risk of mild cognitive impairment and dementia. © The Author(s) 2015.
    American Journal of Alzheimer s Disease and Other Dementias 03/2015; 30(6). DOI:10.1177/1533317515577184 · 1.63 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Brain-derived neurotrophic factor (BDNF) is a pleiotropic peptide involved in maintaining endothelial integrity. It is unknown if circulating BDNF levels are associated with risk of cardiovascular disease (CVD). We prospectively investigated the association of circulating BDNF levels with cardiovascular events and mortality in 3687 participants (mean age 65 years, 2068 women) from the Framingham Heart Study (FHS). Using a common nonsynonomous single nucleotide polymorphism (SNP) in the BDNF gene (rs6265), we then performed a Mendelian randomization experiment in the CARDIoGRAM (Coronary ARtery DIsease Genome-Wide Replication And Meta-Analysis) consortium (>22 000 coronary artery disease [CAD] cases, >60 000 controls) to investigate whether SNP rs6265 was associated with CAD in CARDIoGRAM and, if so, whether the effect estimate differed from that predicted based on FHS data. On follow-up (median 8.9 years), 467 individuals (261 women) in FHS experienced a CVD event, and 835 (430 women) died. In multivariable-adjusted Cox regression, serum BDNF was associated inversely with CVD risk (hazard ratio [HR] per 1-SD increase 0.88, 95% CI 0.80 to 0.97, P=0.01) and with mortality (HR 0.87, 95% CI 0.80 to 0.93, P=0.0002). SNP rs6265 was associated with BDNF concentrations (0.772 ng/mL increase per minor allele copy) in FHS. In CARDIoGRAM, SNP rs6265 was associated with CAD (odds ratio 0.957, 95% CI 0.923 to 0.992), a magnitude consistent with the predicted effect (HR per minor allele copy 0.99, 95% CI 0.98 to 1.0; P=0.06 for difference between predicted and observed effect). Higher serum BDNF is associated with a decreased risk of CVD and mortality. Mendelian randomization suggests a causal protective role of BDNF in the pathogenesis of CVD. © 2015 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.
    Journal of the American Heart Association 02/2015; 4(3). DOI:10.1161/JAHA.114.001544 · 4.31 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: -Cross-sectional epidemiological and clinical research suggest lower cardiac index is associated with abnormal brain aging, including smaller brain volumes, increased white matter hyperintensities, and worse cognitive performances. Lower systemic blood flow may have implications for dementia among older adults. -1039 Framingham Offspring Cohort participants free from clinical stroke, transient ischemic attack, or dementia formed our sample (69±6 years; 53% women). Multivariable-adjusted proportional hazard models adjusting for Framingham Stroke Risk Profile score (age, sex, systolic blood pressure, anti-hypertensive medication, diabetes, cigarette smoking, cardiovascular disease [CVD] history, atrial fibrillation), education, and apolipoprotein E4 status related cardiac MRI-assessed cardiac index (cardiac output/body surface area) to incident all-cause dementia and Alzheimer's disease (AD). Over the median 7.7 year follow-up period, 32 participants developed dementia, including 26 cases of AD. Each one standard deviation unit decrease in cardiac index increased the relative risk of both dementia (HR=1.66; 95% confidence intervals [CI], 1.11-2.47; p=0.013) and AD (HR=1.65; 95% CI, 1.07-2.54; p=0.022). Compared to normal cardiac index, individuals with clinically low cardiac index had a higher relative risk of dementia (HR=2.07; 95% CI, 1.02-4.19; p=0.044). If participants with clinically prevalent CVD and atrial fibrillation were excluded (n=184), individuals with clinically low cardiac index had a higher relative risk of both dementia (HR=2.92; 95% CI, 1.34-6.36; p=0.007) and AD (HR=2.87; 95% CI, 1.21-6.80; p=0.016) compared to individuals with normal cardiac index. -Lower cardiac index is associated with an increased risk for the development of dementia and AD.
    Circulation 02/2015; 10(4). DOI:10.1161/CIRCULATIONAHA.114.012438 · 14.43 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: -The burden of cerebral white matter hyperintensities (WMH) is associated with an increased risk of stroke, dementia, and death. WMH are highly heritable, but their genetic underpinnings are incompletely characterized. To identify novel genetic variants influencing WMH burden, we conducted a meta-analysis of multi-ethnic genome-wide association studies. -We included 21,079 middle-aged to elderly individuals from 29 population-based cohorts, who were free of dementia and stroke and were of European (N=17,936), African (N=1,943), Hispanic (N=795), and Asian (N=405) descent. WMH burden was quantified on MRI either by a validated automated segmentation method or a validated visual grading scale. Genotype data in each study were imputed to the 1000 Genomes reference. Within each ethnic group, we investigated the relationship between each SNP and WMH burden using a linear regression model adjusted for age, sex, intracranial volume, and principal components of ancestry. A meta-analysis was conducted for each ethnicity separately and for the combined sample. In the European descent samples, we confirmed a previously known locus on chr17q25 (p=2.7×10(-19)) and identified novel loci on chr10q24 (p=1.6×10(-9)) and chr2p21 (p=4.4×10(-8)). In the multi-ethnic meta-analysis, we identified two additional loci, on chr1q22 (p=2.0×10(-8)) and chr2p16 (p=1.5×10(-8)). The novel loci contained genes that have been implicated in Alzheimer's disease (chr2p21, chr10q24), intracerebral hemorrhage (chr1q22), neuro-inflammatory diseases (chr2p21), and glioma (chr10q24, chr2p16). -We identified four novel genetic loci that implicate inflammatory and glial proliferative pathways in the development of white matter hyperintensities in addition to previously-proposed ischemic mechanisms.
    Circulation Cardiovascular Genetics 02/2015; 8(2). DOI:10.1161/CIRCGENETICS.114.000858 · 4.60 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: General cognitive function is substantially heritable across the human life course from adolescence to old age. We investigated the genetic contribution to variation in this important, health- and well-being-related trait in middle-aged and older adults. We conducted a meta-analysis of genome-wide association studies of 31 cohorts (N=53 949) in which the participants had undertaken multiple, diverse cognitive tests. A general cognitive function phenotype was tested for, and created in each cohort by principal component analysis. We report 13 genome-wide significant single-nucleotide polymorphism (SNP) associations in three genomic regions, 6q16.1, 14q12 and 19q13.32 (best SNP and closest gene, respectively: rs10457441, P=3.93 × 10−9, MIR2113; rs17522122, P=2.55 × 10−8, AKAP6; rs10119, P=5.67 × 10−9, APOE/TOMM40). We report one gene-based significant association with the HMGN1 gene located on chromosome 21 (P=1 × 10−6). These genes have previously been associated with neuropsychiatric phenotypes. Meta-analysis results are consistent with a polygenic model of inheritance. To estimate SNP-based heritability, the genome-wide complex trait analysis procedure was applied to two large cohorts, the Atherosclerosis Risk in Communities Study (N=6617) and the Health and Retirement Study (N=5976). The proportion of phenotypic variation accounted for by all genotyped common SNPs was 29% (s.e.=5%) and 28% (s.e.=7%), respectively. Using polygenic prediction analysis, ~1.2% of the variance in general cognitive function was predicted in the Generation Scotland cohort (N=5487; P=1.5 × 10−17). In hypothesis-driven tests, there was significant association between general cognitive function and four genes previously associated with Alzheimer’s disease: TOMM40, APOE, ABCG1 and MEF2C.
    Molecular Psychiatry 02/2015; 20(2). DOI:10.1038/mp.2014.188 · 14.50 Impact Factor

Publication Stats

14k Citations
1,740.65 Total Impact Points

Top Journals


  • 2015
    • University of California, Davis
      Davis, California, United States
    • Drexel University
      • Department of Neurology
      Filadelfia, Pennsylvania, United States
    • McMaster University
      Hamilton, Ontario, Canada
  • 2006-2015
    • National Heart, Lung, and Blood Institute
      • Division of Cardiovascular Sciences (DCVS)
      베서스다, Maryland, United States
  • 1998-2015
    • Boston University
      • • Department of Biostatistics
      • • Department of Neurology
      • • School of Public Health
      • • Section of Endocrinology, Diabetes, Nutrition
      • • Department of Mathematics and Statistics
      Boston, Massachusetts, United States
  • 2004-2013
    • University of Massachusetts Boston
      • Clinical Epidemiology Research and Training Unit
      Boston, Massachusetts, United States
    • Northwestern University
      • Department of Preventive Medicine
      Evanston, Illinois, United States
  • 2002
    • University of Washington Seattle
      Seattle, Washington, United States