Publications (23)180.36 Total impact
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Article: Association of Parental Stroke With Brain Injury and Cognitive Measures in Offspring: The Framingham Heart Study.
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ABSTRACT: BACKGROUND AND PURPOSE: Parental stroke has been related to an increased risk of stroke in the offspring. This study examines whether parental stroke is also associated with increased vascular brain injury and poorer cognitive performance among offspring free of clinical stroke. METHODS: Multivariable regression analyses were used to relate parental stroke to cross-sectional and change in brain magnetic resonance imaging measures and cognitive function among the offspring, with and without adjustment for vascular risk factors. RESULTS: Stroke- and dementia-free Framingham Offspring (n=1297, age, 61±9 years, 54% women) were studied. Parental stroke by age 65 years was associated with a higher baseline white matter hyperintensity volume (β=0.17±0.08; P=0.027) and with lower visual memory performance (β= -0.80±0.34; P=0.017). During a 6-year follow-up, parental stroke was also associated with increase in white matter hyperintensity volume (odds ratio [OR], 1.87; 95% confidence interval [CI], 1.03-3.38) and decline in executive function (Trails B-A; OR, 1.81; 95% CI, 1.06-3.09). The associations with white matter hyperintensity volume and visual memory attenuated after additional adjustment for concomitant vascular risk factors. CONCLUSIONS: Parental stroke by age 65 years is associated with increased vascular brain injury and lower memory in offspring equivalent to 3 and 7 years of brain aging, respectively. This may be partly attributed to inheritance of vascular risk factors.Stroke 01/2013; · 5.73 Impact Factor -
Article: The framingham heart study clock drawing performance: normative data from the offspring cohort.
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ABSTRACT: Background/Study Context: Although the Clock Drawing Test (CDT) is a popular tool used to assess cognitive function, limited normative data on CDT performance exist. The objective of the current study was to provide normative data on an expanded version of previous CDT scoring protocols from a large community-based sample of middle to older adults (aged 43 to 91) from the Framingham Heart Study. Methods: The CDT was administered to 1476 Framingham Heart Study Offspring Cohort participants using a scoring protocol that assigned error scores to drawn features. Total error scores were computed, as well as for subscales pertaining to outline, numeral placement, time-setting, center, and "other." Results: Higher levels of education were significantly associated with fewer errors for time-setting (Command: p < .001; Copy: p = .003), numerals (Command: p < .001), and "other" (Command: p < .001) subscales. Older age was significantly associated with more errors for time-setting (Command: p < .001; Copy: p = .003), numerals (Command: p < .001), and "other" (Command: p < .001) subscales. Significant differences were also found between education groups on the Command condition for all but the oldest age group (75+). Conclusion: Results provide normative data on CDT performance within a community-based cohort. Errors appear to be more prevalent in older compared with younger individuals, and may be less prevalent in individuals who completed at least some college compared with those who did not. Future studies are needed to determine whether this expanded scoring system allows detection of preclinical symptoms of future risk for dementia.Experimental Aging Research 01/2013; 39(1):80-108. · 1.31 Impact Factor -
Article: Lipoprotein phospholipase A2 and cerebral microbleeds in the framingham heart study.
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ABSTRACT: Cerebral microbleeds (CMB) attributable to cerebral amyloid angiopathy generally occur in lobar regions, whereas those attributable to hypertensive vasculopathy are deep. Inflammation may be an underlying mechanism for CMB, with varying associations according to CMB location. Lipoprotein phospholipase-A2 (Lp-PLA2) is a circulating enzyme marker of vascular inflammation associated with risk of ischemic stroke and dementia. We hypothesized that higher Lp-PLA2 levels would be related to higher prevalence of CMB, with possible regional specificity. Framingham Offspring participants aged 65 years or older with available Lp-PLA2 measures and brain magnetic resonance imaging were included. Logistic regression models were used to relate Lp-PLA2 activity and mass to presence of CMB, adjusted for age, sex, medication use (aspirin, anticoagulants, and statins), systolic blood pressure, APOE, current smoking, and diabetes. Eight-hundred nineteen participants (mean age, 73 years; 53% women) were included; 106 (13%) had CMB, 82 (10%) were lobar, and 27 (3%) were deep. We did not observe significant associations of CMB and LpPLA2 measures in multivariable adjusted analyses. However, there was a significant interaction between APOE genotype and Lp-PLA2 activity in their relation to presence of deep CMB (P interaction=0.01). Among persons with APOE ε3/ε3, the odds ratio for deep CMB was 0.95 (confidence interval, 0.59-1.53; P=0.83), whereas among those with at least 1 ε2 or ε4 allele, odds ratio was 3.46 (confidence interval, 1.43-8.36; P=0.006). In our community-based sample of older adults, there was no significant association of Lp-PLA2 with total or lobar CMB. The association of higher levels of Lp-PLA2 activity with deep CMB among those with at least 1 APOE ε2 or ε4 allele merits replication.Stroke 09/2012; 43(11):3091-4. · 5.73 Impact Factor -
Article: Risk Estimations, Risk Factors, and Genetic Variants Associated with Alzheimer's Disease in Selected Publications from the Framingham Heart Study.
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ABSTRACT: The study of Alzheimer's disease (AD) in the Framingham Heart Study (FHS), a multi-generational, community-based population study, began nearly four decades ago. In this overview, we highlight findings from seven prior publications that examined lifetime risk estimates for AD, environmental risk factors for AD, circulating and imaging markers of aging-related brain injury, and explorations on the genetics underlying AD. First, we describe estimations of the lifetime risk of AD. These estimates are distinguished from other measures of disease burden and have substantial public health implications. We then describe prospective studies of environmental AD risk factors: one examined the association between plasma levels of omega-3 fatty-acid and risk of incident AD, the other explored the association of diabetes to this risk in subsamples with specific characteristics. With evidence of inflammation as an underlying mechanism, we also describe findings from a study that compared the effects of serum cytokines and spontaneous production of peripheral blood mononuclear cell cytokines on AD risk. Investigating AD related endophenotypes increases sensitivity in identifying risk factors and can be used to explore pathophysiologic pathways between a risk factor and the disease. We describe findings of an association between large volume of white matter hyperintensities and a specific pattern of cognitive deficits in non-demented participants. Finally, we summarize our findings from two genetic studies: The first used genome-wide association (GWA) and family-based association methods to explore the genetic basis of cognitive and structural brain traits. The second is a large meta-analysis GWA study of AD, in which novel loci of AD susceptibility were found. Together, these findings demonstrate the FHS multi-directional efforts in investigating dementia and AD.Journal of Alzheimer's disease: JAD 07/2012; · 3.74 Impact Factor -
Article: Multiple biomarkers and risk of clinical and subclinical vascular brain injury: the Framingham Offspring Study.
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ABSTRACT: Several biomarkers have been individually associated with vascular brain injury, but no prior study has explored the simultaneous association of a biologically plausible panel of biomarkers with the incidence of stroke/transient ischemic attack and the prevalence of subclinical brain injury. In 3127 stroke-free Framingham offspring (age, 59±10 years; 54% female), we related a panel of 8 biomarkers assessing inflammation (C-reactive protein), hemostasis (D-dimer and plasminogen activator inhibitor-1), neurohormonal activity (aldosterone-to-renin ratio, B-type natriuretic peptide, and N-terminal proatrial natriuretic peptides), and endothelial function (homocysteine and urinary albumin/creatinine ratio) measured at the sixth examination (1995-1998) to risk of incident stroke/transient ischemic attack. In a subset of 1901 participants with available brain magnetic resonance imaging (1999-2005), we further related these biomarkers to total cerebral brain volume, covert brain infarcts, and large white-matter hyperintensity volume. During a median follow-up of 9.2 years, 130 participants experienced incident stroke/transient ischemic attack. In multivariable analyses adjusted for stroke risk factors, the biomarker panel was associated with incident stroke/transient ischemic attack and with total cerebral brain volume (P<0.05 for both) but not with covert brain infarcts or white-matter hyperintensity volume (P>0.05). In backward elimination analyses, higher log-B-type natriuretic peptide (hazard ratio, 1.39 per 1-SD increment; P=0.002) and log-urinary albumin/creatinine ratio (hazard ratio, 1.31 per 1-SD increment; P=0.004) were associated with increased risk of stroke/transient ischemic attack and improved risk prediction compared with the Framingham Stroke Risk Profile alone; when the <5%, 5% to 15%, or >15% 10-year risk category was used, the net reclassification index was 0.109 (P=0.037). Higher C-reactive protein (β=-0.21 per 1-SD increment; P=0.008), D-dimer (β=-0.18 per 1-SD increment; P=0.041), total homocysteine (β=-0.21 per 1-SD increment; P=0.005), and urinary albumin/creatinine ratio (β=-0.15 per 1-SD increment; P=0.042) were associated with lower total cerebral brain volume. In a middle-aged community sample, we identified multiple biomarkers that were associated with clinical and subclinical vascular brain injury and could improve risk stratification.Circulation 03/2012; 125(17):2100-7. · 14.74 Impact Factor -
Article: Biomarkers for Insulin Resistance and Inflammation and the Risk for All-Cause Dementia and Alzheimer Disease: Results From the Framingham Heart Study.
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ABSTRACT: OBJECTIVE: To investigate the contribution of biomarkers of glucose homeostasis (adiponectin, glucose, glycated albumin, and insulin levels) and inflammation (high-sensitivity C-reactive protein and lipoprotein-associated phospholipase A(2) levels) to the risk of developing Alzheimer disease (AD) and all-cause dementia. DESIGN: Prospective cohort study. SETTING: Dementia-free Framingham Heart Study participants had sera measured for these biomarkers at the 19th biennial examination (1985-1988) and were followed up prospectively for the development of AD and all-cause dementia. PARTICIPANTS: Eight hundred forty (541 women, median age of 76 years) subjects participated in the study. MAIN OUTCOME MEASURES: We used sex-pooled and sex-specific multivariable Cox proportional hazards models adjusted for age, education, body mass index, recent change in weight, APOE ε4 allele status, and plasma docosahexaenoic acid levels to determine association of these biomarkers with the development of all-cause dementia and AD. RESULTS: Over a mean follow-up period of 13 years, 159 persons developed dementia (including 125 with AD). After adjustment for other risk factors, only adiponectin in women was associated with an increased risk of all-cause dementia (hazard ratio [HR], 1.29; 95% confidence interval [CI], 1.00-1.66; P = .054) and AD (HR, 1.33; 95% CI, 1.00-1.76; P = .050) per 1-SD increase in adiponectin level. Women with baseline adiponectin values more than the median had a higher risk of all-cause dementia (HR, 1.63; 95% CI, 1.03-2.56; P = .04) and AD (HR, 1.87; 95% CI, 1.13-3.10; P = .01) as compared with those with values less than the median. CONCLUSION: In women, increased plasma adiponectin levels are an independent risk factor for the development of both all-cause dementia and AD.Archives of neurology 01/2012; · 6.31 Impact Factor -
Article: Relation of left ventricular ejection fraction to cognitive aging (from the Framingham Heart Study).
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ABSTRACT: Heart failure is a risk factor for Alzheimer's disease and cerebrovascular disease. In the absence of heart failure, it was hypothesized that left ventricular ejection fraction (LVEF), an indicator of cardiac dysfunction, would be associated with preclinical brain magnetic resonance imaging (MRI) and neuropsychological markers of ischemia and Alzheimer disease in the community. Brain MRI, cardiac MRI, neuropsychological, and laboratory data were collected from 1,114 Framingham Heart Study Offspring Cohort participants free from clinical stroke or dementia (aged 40 to 89 years, mean age 67 ± 9 years, 54% women). Neuropsychological and neuroimaging markers of brain aging were related to cardiac MRI-assessed LVEF. In multivariable-adjusted linear regressions, LVEF was not associated with any brain aging variable (p values >0.15). However, LVEF quintile analyses yielded several U-shaped associations. Compared to the referent (quintile 2 to 4), the lowest quintile (quintile 1) LVEF was associated with lower mean cognitive performance, including Visual Reproduction Delayed Recall (β = -0.27, p <0.001) and Hooper Visual Organization Test (β = -0.27, p <0.001). Compared to the referent, the highest quintile (quintile 5) LVEF values also were associated with lower mean cognitive performance, including Logical Memory Delayed Recall (β = -0.18, p = 0.03), Visual Reproduction Delayed Recall (β = -0.17, p = 0.03), Trail Making Test Part B - Part A (β = -0.22, p = 0.02), and Hooper Visual Organization Test (β = -0.20, p = 0.02). Findings were similar when analyses were repeated excluding prevalent cardiovascular disease. In conclusion, although these observational cross-sectional data cannot establish causality, they suggest a nonlinear association between LVEF and measures of accelerated cognitive aging.The American journal of cardiology 08/2011; 108(9):1346-51. · 3.58 Impact Factor -
Article: Inflammatory markers and neuropsychological functioning: the Framingham Heart Study.
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ABSTRACT: We hypothesized that inflammatory markers are cross-sectionally and longitudinally associated with neuropsychological indicators of early ischemia and Alzheimer's disease. Framingham Offspring Study participants, free of clinical stroke or dementia (n = 1,878; 60 ± 9 years; 54% women), underwent neuropsychological assessment and ascertainment of 11 inflammatory markers. Follow-up neuropsychological assessments (6.3 ± 1.0 years) were conducted on 1,352 of the original 1,878 participants. Multivariable linear regression related the inflammatory markers to cross-sectional performance and longitudinal change in neuropsychological performances. Secondary models included a twelfth factor, tumor necrosis factor-α (TNF-α), available on a subset of the sample (n = 1,393 cross-sectional; n = 1,213 longitudinal). Results suggest a few modest cross-sectional inflammatory and neuropsychological associations, particularly for tests assessing visual organization (C-reactive protein, p = 0.007), and a few modest relations between inflammatory markers and neuropsychological change, particularly for executive functioning (TNF-α, p = 0.004). Secondary analyses suggested that inflammatory markers were cross-sectionally (TNF-α, p = 0.004) related to reading performance. Our findings are largely negative, but suggest that specific inflammatory markers may have limited associations with poorer cognition and reading performance among community-dwelling adults. Because of multiple testing concerns, our limited positive findings are offered as hypothesis generating and require replication in other studies.Neuroepidemiology 07/2011; 37(1):21-30. · 2.31 Impact Factor -
Article: Association of metabolic dysregulation with volumetric brain magnetic resonance imaging and cognitive markers of subclinical brain aging in middle-aged adults: the Framingham Offspring Study.
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ABSTRACT: Diabetic and prediabtic states, including insulin resistance, fasting hyperglycemia, and hyperinsulinemia, are associated with metabolic dysregulation. These components have been individually linked to increased risks of cognitive decline and Alzheimer's disease. We aimed to comprehensively relate all of the components of metabolic dysregulation to cognitive function and brain magnetic resonance imaging (MRI) in middle-aged adults. Framingham Offspring participants who underwent volumetric MRI and detailed cognitive testing and were free of clinical stroke and dementia during examination 7 (1998-2001) constituted our study sample (n = 2,439; 1,311 women; age 61 ± 9 years). We related diabetes, homeostasis model assessment of insulin resistance (HOMA-IR), fasting insulin, and glycohemoglobin levels to cross-sectional MRI measures of total cerebral brain volume (TCBV) and hippocampal volume and to verbal and visuospatial memory and executive function. We serially adjusted for age, sex, and education alone (model A), additionally for other vascular risk factors (model B), and finally, with the inclusion of apolipoprotein E-ε4, plasma homocysteine, C-reactive protein, and interleukin-6 (model C). We observed an inverse association between all indices of metabolic dysfunction and TCBV in all models (P < 0.030). The observed difference in TCBV between participants with and without diabetes was equivalent to approximately 6 years of chronologic aging. Diabetes and elevated glycohemoglobin, HOMA-IR, and fasting insulin were related to poorer executive function scores (P < 0.038), whereas only HOMA-IR and fasting insulin were inversely related to visuospatial memory (P < 0.007). Metabolic dysregulation, especially insulin resistance, was associated with lower brain volumes and executive function in a large, relatively healthy, middle-aged, community-based cohort.Diabetes care 06/2011; 34(8):1766-70. · 8.09 Impact Factor -
Article: Association of HSP70 and its co-chaperones with Alzheimer's disease.
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ABSTRACT: The heat shock protein (HSP) 70 family has been implicated in the pathology of Alzheimer's disease (AD). In this study, we examined common genetic variations in the 80 genes encoding HSP70 and its co-chaperones. We conducted a study in a series of 462 patients and 5238 unaffected participants derived from the Rotterdam Study, a population-based study including 7983 persons aged 55 years and older. We genotyped a total of 12,053 Single Nucleotide Polymorphisms (SNPs) using the HumanHap550K Genotyping BeadChip from Illumina. Replication was performed in two independent cohort studies, the Framingham Heart study (FHS; n = 806) and Cardiovascular Health Study (CHS; n = 2150). When adjusting for multiple testing, we found a small but consistent, though not significant effect of rs12118313 located 32 kb from PFDN2, with an OR of 1.19 (p-value from meta-analysis = 0.003). However this SNP was in the intron of another gene, suggesting it is unlikely this SNP reflects the effect of PFDN2. In a formal pathway analysis we found nominally significant evidence for an association of BAG, DNAJA and prefoldin with AD. These findings corroborate with those of a study of 2032 AD patients and 5328 controls, in which several members of the prefoldin family showed evidence for association to AD. Our study did not reveal evidence for a genetic variant if the HSP70 family with a major effect on AD. However, our findings of the single SNP analysis and pathway analysis suggest that multiple genetic variants in prefoldin are associated with AD.Journal of Alzheimer's disease: JAD 03/2011; 25(1):93-102. · 3.74 Impact Factor -
Article: Cardiac index is associated with brain aging: the Framingham Heart Study.
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ABSTRACT: Cardiac dysfunction is associated with neuroanatomic and neuropsychological changes in aging adults with prevalent cardiovascular disease, theoretically because systemic hypoperfusion disrupts cerebral perfusion, contributing to subclinical brain injury. We hypothesized that cardiac function, as measured by cardiac index, would be associated with preclinical brain magnetic resonance imaging (MRI) and neuropsychological markers of ischemia and Alzheimer disease in the community. Brain MRI, cardiac MRI, neuropsychological, and laboratory data were collected on 1504 Framingham Offspring Cohort participants free of clinical stroke, transient ischemic attack, or dementia (age, 61+/-9 years; 54% women). Neuropsychological and brain MRI variables were related to cardiac MRI-assessed cardiac index (cardiac output/body surface area). In multivariable-adjusted models, cardiac index was positively related to total brain volume (P=0.03) and information processing speed (P=0.02) and inversely related to lateral ventricular volume (P=0.048). When participants with clinically prevalent cardiovascular disease were excluded, the relation between cardiac index and total brain volume remained (P=0.02). Post hoc comparisons revealed that participants in the bottom cardiac index tertile (values <2.54) and middle cardiac index tertile (values between 2.54 and 2.92) had significantly lower brain volumes (P=0.04) than participants in the top cardiac index tertile (values >2.92). Although observational data cannot establish causality, our findings are consistent with the hypothesis that decreasing cardiac function, even at normal cardiac index levels, is associated with accelerated brain aging.Circulation 08/2010; 122(7):690-7. · 14.74 Impact Factor -
Article: Association of plasma leptin levels with incident Alzheimer disease and MRI measures of brain aging.
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ABSTRACT: The adipokine leptin facilitates long-term potentiation and synaptic plasticity in the hippocampus, promotes beta-amyloid clearance, and improves memory function in animal models of aging and Alzheimer disease (AD). To relate baseline circulating leptin concentrations in a community-based sample of individuals without dementia to incident dementia and AD during follow-up and magnetic resonance imaging (MRI) measures of brain aging in survivors. Prospective study of plasma leptin concentrations measured in 785 persons without dementia (mean [SD] age, 79 [5] years; 62% female), who were in the Framingham original cohort at the 22nd examination cycle (1990-1994). A subsample of 198 dementia-free survivors underwent volumetric brain MRI between 1999 and 2005, approximately 7.7 years after leptin was assayed. Two measures of brain aging, total cerebral brain volume and temporal horn volume (which is inversely related to hippocampal volume) were assessed. Incidence of dementia and AD during follow-up until December 31, 2007. During a median follow-up of 8.3 years (range, 0-15.5 years), 111 participants developed incident dementia; 89 had AD. Higher leptin levels were associated with a lower risk of incident dementia and AD in multivariable models (hazard ratio per 1-SD increment in log leptin was 0.68 [95% confidence interval, 0.54-0.87] for all-cause dementia and 0.60 [95% confidence interval, 0.46-0.79] for AD). This corresponds to an absolute AD risk over a 12-year follow-up of 25% for persons in the lowest quartile (first quartile) vs 6% for persons in the fourth quartile of sex-specific leptin levels. In addition, a 1-SD elevation in plasma leptin level was associated with higher total cerebral brain volume and lower temporal horn volume, although the association of leptin level with temporal horn volume did not reach statistical significance. Circulating leptin was associated with a reduced incidence of dementia and AD and with cerebral brain volume in asymptomatic older adults.JAMA The Journal of the American Medical Association 12/2009; 302(23):2565-72. · 30.03 Impact Factor -
Article: Association of plasma ADMA levels with MRI markers of vascular brain injury: Framingham offspring study.
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ABSTRACT: Asymmetrical dimethylarginine (ADMA), an inhibitor of endothelial nitric oxide synthase, is a marker of endothelial dysfunction. Elevated circulating ADMA concentrations have been associated with systemic and carotid atherosclerosis, an elevated risk of developing stroke, and magnetic resonance imaging white-matter hyperintensities (WMHs). The relation of plasma ADMA to subclinical vascular brain injury has not been previously studied in a middle-aged, community-based sample. In 2013 stroke-free Framingham offspring (mean+/-SD age, 58+/-9.5 years; 53% women), we related baseline plasma ADMA levels (1995-1998) to subsequent brain magnetic resonance imaging measures (1999-2004) of subclinical vascular injury: presence of silent brain infarcts (SBIs) and large white-matter hyperintensity volumes (LWMHs; defined as >1 SD above the age-specific mean). Prevalences of SBIs and LWMHs were 10.7% and 12.6%, respectively. In multivariable analyses adjusting for age, sex and traditional stroke risk factors, higher ADMA levels were associated with an increased risk of prevalent SBIs (odds ratio [OR] per 1-SD increase in ADMA=1.16; 95% CI, 1.01 to 1.33; P=0.04). We observed that participants in the upper 3 age-specific quartiles (Qs) of plasma ADMA values had an increased prevalence of SBIs (OR for Q2-Q4 vs Q1=1.43; 95% CI, 1.00 to 2.04; P<0.05). The prevalence of SBIs in Q1and Q2-Q4 was 8.3% and 11.6%, respectively. The prevalence of LWMHs did not differ according to ADMA concentrations. Higher plasma ADMA values were associated with an increased prevalence of SBIs, after adjustment for traditional stroke risk factors. Thus, ADMA may be a potentially useful new biomarker of subclinical vascular brain injury, which is an important correlate of vascular cognitive impairment and risk of stroke.Stroke 07/2009; 40(9):2959-64. · 5.73 Impact Factor -
Article: Age at natural menopause and risk of ischemic stroke: the Framingham heart study.
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ABSTRACT: Women have increased lifetime stroke risk and more disabling strokes compared with men. Insights into the association between menopause and stroke could lead to new prevention strategies for women. The objective of this study was to examine the association of age at natural menopause with ischemic stroke risk in the Framingham Heart Study. Participants included women who survived stroke-free until age 60, experienced natural menopause, did not use estrogen before menopause, and who had complete data (n=1430). Participants were followed until first ischemic stroke, death, or end of follow-up (2006). Age at natural menopause was self-reported. Cox proportional hazards models were used to examine the association between age at natural menopause (<42, 42 to 54, >or=55) and ischemic stroke risk adjusted for age, systolic blood pressure, atrial fibrillation, diabetes, current smoking, cardiovascular disease and estrogen use. There were 234 ischemic strokes identified. Average age at menopause was 49 years (SD=4). Women with menopause at ages 42 to 54 (hazard ratio=0.50; 95% CI: 0.29 to 0.89) and at ages >or=55 (hazard ratio=0.31; 95% CI: 0.13 to 0.76) had lower stroke risk compared with those with menopause <42 years adjusted for covariates. Women with menopause before age 42 had twice the stroke risk compared to all other women (hazard ratio=2.03; 95% CI: 1.16 to 3.56). In this prospective study, age at natural menopause before age 42 was associated with increased ischemic stroke risk. Future stroke studies with measures of endogenous hormones are needed to inform the underlying mechanisms so that novel prevention strategies for midlife women can be considered.Stroke 03/2009; 40(4):1044-9. · 5.73 Impact Factor -
Article: Gender differences in stroke incidence and poststroke disability in the Framingham heart study.
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ABSTRACT: Stroke is emerging as a major public health problem for women, as it is for men. Controversy persists regarding gender differences in stroke incidence, severity, and poststroke disability. Participants in the Framingham Original (n=5119; 2829 women) and Offspring (n=4957, 2565 women) cohorts who were 45 years and stroke-free were followed to first incident stroke. Gender-specific outcome measures were adjusted for the Framingham Stroke Risk Profile components. We observed 1136 incident strokes (638 in women) over 56 years of follow-up. Women were significantly (P<0.001) older (75.1 versus 71.1 years for men) at their first-ever stroke, had a higher stroke incidence above 85 years of age, lower at all other ages, and a higher lifetime risk of stroke at all ages. There was no significant difference in stroke subtype, stroke severity, and case fatality rates between genders. Women were significantly (P<0.01) more disabled before stroke and in the acute phase of stroke in dressing (59% versus 37%), grooming (57% versus 34%), and transfer from bed to chair (59% versus 35%). At 3 to 6 months poststroke women were more disabled, more likely to be single, and 3.5 times more likely to be institutionalized (P<0.01). These results from the Framingham Heart Study (FHS) support the existence of gender-differences in stroke incidence, lifetime risk (LTR) of stroke, age at first stroke, poststroke disability, and institutionalization rates. Prestroke disability and sociodemographic factors may contribute to the high rate of institutionalization and poorer outcome observed in women.Stroke 02/2009; 40(4):1032-7. · 5.73 Impact Factor -
Article: Association of matrix metalloproteinases with MRI indices of brain ischemia and aging.
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ABSTRACT: Magnetic resonance imaging (MRI) findings of large white matter hyperintensities (LWMH), decreased brain volume and silent cerebral infarcts (SCI) are subclinical indices of brain ischemia and aging. Although the pathophysiology of these findings remains uncertain, extracellular matrix (ECM) remodeling, a process regulated by matrix metalloproteinases (MMPs) and their inhibitors (TIMPs), may be implicated. We evaluated the cross-sectional relations of circulating MMP-9 and TIMP-1 to these MRI indices in 583 stroke and dementia-free, Framingham Offspring participants (mean age 57 years, 58% women). Using multivariable regression MMP-9 (detectable versus non-detectable) and TIMP-1 (modeled as sex-specific quartiles) were related to LWMH (>1S.D. above age-specific mean; yes/no), SCI (yes/no) and total brain volume (ratio of parenchymal to intracranial volume, TCBVr). Mean TCBVr was 0.78 (S.D. 0.03), 13% of subjects had LWMH and 12% had SCI. Detectable MMP-9 was associated with higher prevalence of LWMH (OR 2.09, 95%confidence interval (CI) 1.00-4.37), but not with TCBVr. TIMP-1 was associated with a high prevalence of LWMH (OR for Q4 versus Q1-3: 1.83, 95%CI 1.06-3.18) and with lower mean TCBVr (Q4 associated with 0.17 S.D. units lower value relative to Q1-3; p=0.04). Neither biomarker was associated with SCI. Our findings are preliminary but if confirmed in further studies, suggest a pathophysiological role for the MMP/TIMP pathway in processes of brain ischemia and aging.Neurobiology of aging 01/2009; 31(12):2128-35. · 5.94 Impact Factor -
Article: Association of plasma total homocysteine levels with subclinical brain injury: cerebral volumes, white matter hyperintensity, and silent brain infarcts at volumetric magnetic resonance imaging in the Framingham Offspring Study.
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ABSTRACT: Elevated plasma total homocysteine (tHcy) levels have been associated with increased risk of dementia and stroke, but it is uncertain whether the mediating mechanisms are predominantly cellular, vascular, or both. To evaluate the relationship between tHcy levels and findings at brain magnetic resonance imaging (MRI) in a community-based sample. Our sample comprised 1965 participants in the Framingham Offspring Study (1050 women; mean [SD] age, 62 [9] years) who were free of clinical stroke, dementia, or other neurologic disease affecting brain MRI and for whom at least 1 measurement of plasma tHcy level (1991-2001) and a brain MRI (1999-2002) were available. We used multivariate regression analysis to relate initial (1991-1995) and concurrent (1998-2001) plasma tHcy levels to total cerebral brain volume and lobar volumes as measures of neuronal loss and atrophy and to the presence or absence of silent brain infarcts and extensive white matter hyperintensity (log-white matter intensity > or =1 SD above the age-adjusted mean) as separate measures of vascular injury. Mean total cerebral brain volume was 78%. At MRI, 218 participants had silent brain infarcts and 250 demonstrated extensive white matter hyperintensity. Participants with a plasma tHcy level in the highest age- (-0.37%, P = .01) or sex-specific (-0.48%, P < .001) quartile had smaller total cerebral brain volumes compared with participants with lower tHcy levels. Initial tHcy levels were associated with a higher prevalence of silent brain infarct (relative risk, 1.5; 95% confidence interval, 1.1-2.1; P = .02) and concurrent tHcy levels, with smaller frontal (-0.14%, P = .001) and temporal lobar (-0.10%, P = .04) volumes. Prevalence of extensive white matter hyperintensity did not differ according to initial or concurrent plasma tHcy levels (relative risk, both 1.0; 95% confidence interval, 0.7-1.4 and 0.8-1.4, respectively). Higher plasma tHcy levels are associated with smaller brain volume and the presence of silent brain infarcts at MRI, even in healthy, middle-aged adults. Thus, both cellular and vascular mechanisms may underlie the association of plasma tHcy level with brain aging, as reflected by the effects on both subclinical and overt disease.Archives of neurology 06/2008; 65(5):642-9. · 6.31 Impact Factor -
Article: Prevalence and correlates of silent cerebral infarcts in the Framingham offspring study.
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ABSTRACT: Previous estimates of the prevalence of silent cerebral infarction (SCI) on MRI in community-based samples have varied between 5.8% and 17.7% depending on age, ethnicity, presence of comorbidities, and imaging techniques. We document the prevalence and risk factors associated with SCI at midlife in the community-based Framingham sample. Our study sample comprised 2040 Framingham Offspring (53% female; mean age, 62+/-9 years) who attended the sixth examination (1996-1998), underwent volumetric brain MRI (1999-2005,) and were free of clinical stroke at MRI. We examined the age- and sex-specific prevalences and the clinical correlates of SCI using multivariable logistic regression models. At least 1 SCI was present in 10.7% of participants; 84% had a single lesion. SCI was largely located in the basal ganglia (52%), other subcortical (35%) areas, and cortical areas (11%). Prevalent SCI was associated with the Framingham Stroke Risk Profile score (OR, 1.27; 95% CI, 1.10-1.46); stage I hypertension was determined by JNC-7 criteria (OR,1.56; CI,1.15-2.11), an elevated plasma homocysteine in the highest quartile (OR, 2.23; CI, 1.42-3.51), atrial fibrillation (OR, 2.16; CI, 1.07-4.40), carotid stenosis >25% (OR, 1.62; 1.13-2.34), and increased carotid intimal-medial thickness above the lowest quintile (OR, 1.65; CI, 1.22-2.24). The prevalence and distribution of SCI in the Framingham Offspring are comparable to previous estimates. Risk factors previously associated with clinical stroke were also found to be associated with midlife SCI. Our results support current guidelines emphasizing early detection and treatment of stroke risk factors.Stroke 06/2008; 39(11):2929-35. · 5.73 Impact Factor -
Article: Genetic correlates of brain aging on MRI and cognitive test measures: a genome-wide association and linkage analysis in the Framingham Study.
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ABSTRACT: Brain magnetic resonance imaging (MRI) and cognitive tests can identify heritable endophenotypes associated with an increased risk of developing stroke, dementia and Alzheimer's disease (AD). We conducted a genome-wide association (GWA) and linkage analysis exploring the genetic basis of these endophenotypes in a community-based sample. A total of 705 stroke- and dementia-free Framingham participants (age 62 +9 yrs, 50% male) who underwent volumetric brain MRI and cognitive testing (1999-2002) were genotyped. We used linear models adjusting for first degree relationships via generalized estimating equations (GEE) and family based association tests (FBAT) in additive models to relate qualifying single nucleotide polymorphisms (SNPs, 70,987 autosomal on Affymetrix 100K Human Gene Chip with minor allele frequency > or = 0.10, genotypic call rate > or = 0.80, and Hardy-Weinberg equilibrium p-value > or = 0.001) to multivariable-adjusted residuals of 9 MRI measures including total cerebral brain (TCBV), lobar, ventricular and white matter hyperintensity (WMH) volumes, and 6 cognitive factors/tests assessing verbal and visuospatial memory, visual scanning and motor speed, reading, abstract reasoning and naming. We determined multipoint identity-by-descent utilizing 10,592 informative SNPs and 613 short tandem repeats and used variance component analyses to compute LOD scores. The strongest gene-phenotype association in FBAT analyses was between SORL1 (rs1131497; p = 3.2 x 10(-6)) and abstract reasoning, and in GEE analyses between CDH4 (rs1970546; p = 3.7 x 10(-8)) and TCBV. SORL1 plays a role in amyloid precursor protein processing and has been associated with the risk of AD. Among the 50 strongest associations (25 each by GEE and FBAT) were other biologically interesting genes. Polymorphisms within 28 of 163 candidate genes for stroke, AD and memory impairment were associated with the endophenotypes studied at p < 0.001. We confirmed our previously reported linkage of WMH on chromosome 4 and describe linkage of reading performance to a marker on chromosome 18 (GATA11A06), previously linked to dyslexia (LOD scores = 2.2 and 5.1). Our results suggest that genes associated with clinical neurological disease also have detectable effects on subclinical phenotypes. These hypothesis generating data illustrate the use of an unbiased approach to discover novel pathways that may be involved in brain aging, and could be used to replicate observations made in other studies.BMC Medical Genetics 02/2007; 8 Suppl 1:S15. · 2.33 Impact Factor -
Article: Estimating lifetime risk of developing high serum total cholesterol: adjustment for baseline prevalence and single-occasion measurements.
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ABSTRACT: The lifetime risk statistic is a powerful tool in epidemiology. It has been successfully applied to estimate and highlight the risks of numerous diseases, including breast cancer, Alzheimer's disease, stroke, and coronary heart disease and some of its risk factors. Application of this method to health-related conditions that may have an onset early in young adulthood or to measurements that can fluctuate over time introduces problems of under- or overestimation of risk. To correctly quantify the long-term risk of developing high serum total cholesterol (> or =240 mg/dl or use of lipid-lowering medication), the authors propose a key modification of the lifetime risk statistic: adjustment for baseline prevalence. It accounts for the fact that many people already have the condition at a young age (an age often chosen as baseline). The authors derive point estimators and confidence intervals and supply a SAS macro (SAS Institute, Inc., Cary, North Carolina). For assessment of the risk inflation due to single-occasion measurement, the authors suggest two diagnostic tools, one requiring the condition to be present on two consecutive occasions and the other taking into account intrasubject variability. As an illustration, the authors calculate risk estimates for US Caucasians based on hypercholesterolemia incidence (1971-early 2001) from the Framingham Heart Study and prevalence data from the 1999-2000 National Health and Nutrition Examination Survey.American Journal of Epidemiology 02/2007; 165(4):464-72. · 5.22 Impact Factor
Top Journals
Institutions
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2009–2012
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Boston University
- Department of Neurology
Boston, MA, USA -
University of Michigan
Ann Arbor, MI, USA
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2011
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Harvard University
Boston, MA, USA
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2007
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National Heart, Lung, and Blood Institute
Bethesda, MD, USA
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2006
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Tufts University
- Lipid Metabolism Research Laboratory
Boston, GA, USA
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