49 research outputs found
Mexican American Adults in Higher Education: A Qualitative Study
This study explored the experiences of Mexican Americans who completed a bachelor degree as adult learners. With the primary focus on Mexican Americansâ bicultural experiences, the studyâs findings point to the significance of the process in becoming bicultural and how that process influences college degree attainment
Procalcitonin and midregional proatrial natriuretic peptide as biomarkers of subclinical cerebrovascular damage: the northern manhattan study
BACKGROUND AND PURPOSE: Chronic infections and cardiac dysfunction are risk factors for stroke. We hypothesized that blood biomarkers of infection (procalcitonin) and cardiac dysfunction (midregional proatrial natriuretic peptide [MR-proANP]), previously associated with small vessel stroke and cardioembolic stroke are also associated with subclinical cerebrovascular damage, including silent brain infarcts and white matter hyperintensity volume.
METHODS: The NOMAS (Northern Manhattan Study) was designed to assess risk factors for incident vascular disease in a multiethnic cohort. A subsample underwent brain magnetic resonance imaging and had blood samples available for biomarker measurement (n=1178). We used logistic regression models to estimate the odds ratios and 95% confidence intervals (95% CIs) for the association of these biomarkers with silent brain infarcts after adjusting for demographic, behavioral, and medical risk factors. We used linear regression to assess associations with log-white matter hyperintensity volume.
RESULTS: Mean age was 70±9 years; 60% were women, 66% Hispanic, 17% black, and 15% were white. After adjusting for risk factors, subjects with procalcitonin or MR-proANP in the top quartile, compared with the lowest quartile were more likely to have silent brain infarcts (adjusted odds ratio for procalcitonin, 2.2; 95% CI, 1.3-3.7 and for MR-proANP, 3.3; 95% CI, 1.7-6.3) and increased white matter hyperintensity volume (adjusted mean change in log-white matter hyperintensity volume for procalcitonin, 0.29; 95% CI, 0.13-0.44 and for MR-proANP, 0.18; 95% CI, 0.004-0.36).
CONCLUSIONS: Higher concentrations of procalcitonin, a marker of infection, and MR-proANP, a marker of cardiac dysfunction, are independently associated with subclinical cerebrovascular damage. If further studies demonstrate an incremental value for risk stratification, biomarker-guided primary prevention studies may lead to new approaches to prevent cerebrovascular disease
Cerebral white matter disease and functional decline in older adults from the Northern Manhattan Study: A longitudinal cohort study
Background
Cerebral white matter hyperintensities (WMHs) on MRI are common and associated with vascular and functional outcomes. However, the relationship between WMHs and longitudinal trajectories of functional status is not well characterized. We hypothesized that whole brain WMHs are associated with functional decline independently of intervening clinical vascular events and other vascular risk factors.
Methods and findings
In the Northern Manhattan Study (NOMAS), a population-based racially/ethnically diverse prospective cohort study, 1,290 stroke-free individuals underwent brain MRI and were followed afterwards for a mean 7.3 years with annual functional assessments using the Barthel index (BI) (range 0â100) and vascular event surveillance. Whole brain white matter hyperintensity volume (WMHV) (as percentage of total cranial volume [TCV]) was standardized and treated continuously. Generalized estimating equation (GEE) models tested associations between whole brain WMHV and baseline BI and change in BI, adjusting for sociodemographic, vascular, and cognitive risk factors, as well as stroke and myocardial infarction (MI) occurring during follow-up. Mean age was 70.6 (standard deviation [SD] 9.0) years, 40% of participants were male, 66% Hispanic; mean whole brain WMHV was 0.68% (SD 0.84). In fully adjusted models, annual functional change was â1.04 BI points (â1.20, â0.88), with â0.74 additional points annually per SD whole brain WMHV increase from the mean (â0.99, â0.49). Whole brain WMHV was not associated with baseline BI, and results were similar for mobility and non-mobility BI domains and among those with baseline BI 95â100. A limitation of the study is the possibility of a healthy survivor bias, which would likely have underestimated the associations we found.
Conclusions
In this large population-based study, greater whole brain WMHV was associated with steeper annual decline in functional status over the long term, independently of risk factors, vascular events, and baseline functional status. Subclinical brain ischemic changes may be an independent marker of long-term functional decline
Procalcitonin and midregional proatrial natriuretic peptide as biomarkers of subclinical cerebrovascular damage: the northern manhattan study
BACKGROUND AND PURPOSE: Chronic infections and cardiac dysfunction are risk factors for stroke. We hypothesized that blood biomarkers of infection (procalcitonin) and cardiac dysfunction (midregional proatrial natriuretic peptide [MR-proANP]), previously associated with small vessel stroke and cardioembolic stroke are also associated with subclinical cerebrovascular damage, including silent brain infarcts and white matter hyperintensity volume.
METHODS: The NOMAS (Northern Manhattan Study) was designed to assess risk factors for incident vascular disease in a multiethnic cohort. A subsample underwent brain magnetic resonance imaging and had blood samples available for biomarker measurement (n=1178). We used logistic regression models to estimate the odds ratios and 95% confidence intervals (95% CIs) for the association of these biomarkers with silent brain infarcts after adjusting for demographic, behavioral, and medical risk factors. We used linear regression to assess associations with log-white matter hyperintensity volume.
RESULTS: Mean age was 70±9 years; 60% were women, 66% Hispanic, 17% black, and 15% were white. After adjusting for risk factors, subjects with procalcitonin or MR-proANP in the top quartile, compared with the lowest quartile were more likely to have silent brain infarcts (adjusted odds ratio for procalcitonin, 2.2; 95% CI, 1.3-3.7 and for MR-proANP, 3.3; 95% CI, 1.7-6.3) and increased white matter hyperintensity volume (adjusted mean change in log-white matter hyperintensity volume for procalcitonin, 0.29; 95% CI, 0.13-0.44 and for MR-proANP, 0.18; 95% CI, 0.004-0.36).
CONCLUSIONS: Higher concentrations of procalcitonin, a marker of infection, and MR-proANP, a marker of cardiac dysfunction, are independently associated with subclinical cerebrovascular damage. If further studies demonstrate an incremental value for risk stratification, biomarker-guided primary prevention studies may lead to new approaches to prevent cerebrovascular disease
Social Connectivity is Related to Mild Cognitive Impairment and Dementia
Background: Evidence supports a relationship between loneliness, social isolation, and dementia, but less is known about whether social connections confer protection against cognitive decline in disadvantaged neighborhoods. Objective: This longitudinal population-based study examines the relationship between social connectivity and cognitive impairment in a multi-ethnic cohort with low socioeconomic status and high vascular disease risk. Methods: Northern Manhattan Study participants self-reported frequency of social visits, phone calls, satisfaction with social visits, number of friends, and loneliness at baseline, and were followed prospectively with a series of neuropsychological assessments. Social connectivity was examined in relation to incident mild cognitive impairment (MCI)/dementia using logistic regression adjusting for demographics and vascular risk factors. Results: Among 952 participants (mean age at first neuropsychological assessment = 69±8 years, 62% women, 17% Black, 13% white, 68% Hispanic), 24% developed MCI/dementia. Participants who had phone contact with friends/family 2 + times/week (91%) had a lower odds of MCI/dementia (OR = 0.52, 95% CI = 0.31â0.89), with no association for frequency of in-person visits. Compared to those who were neither socially isolated (â„3 friends) nor lonely (reference, 73%), those who were socially isolated and lonely (3%) had an increased odds of MCI/dementia (OR = 2.89, 95% CI = 1.19â7.02), but differences were not observed for those who were socially isolated but not lonely (10%, OR = 1.05, 95% CI = 0.60â1.84), nor those who were lonely but not isolated (11%, OR = 1.58, 95% CI = 0.97â2.59). Conclusion: This study raises the possibility that social connections confer some protection for cognitive health in the face of adversity and supports potential opportunities for community social interventions for improving cognition in disadvantaged populations
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Abstract 54: Procalcitonin, Copeptin and Midregional Pro-atrial Natriuretic Peptide as Markers of Ischemic Stroke Risk: The Northern Manhattan Study
Background:
Chronic infections and neuroendocrine dysfunction may be risk factors for ischemic stroke. We hypothesized that selected blood biomarkers of infection (procalcitonin, or PCT), hypothalamic-pituitary-axis function (copeptin), and hemodynamic stress (midregional pro-atrial natriuretic peptide, or MRproANP) would be associated with incident ischemic stroke risk in the multi-ethnic, urban Northern Manhattan Study (NOMAS) cohort.
Methods:
A case-cohort study was performed among initially stroke-free participants from the prospective population-based NOMAS study. The mean follow up was 11 years. Cases were defined as first ischemic stroke (including fatal) with available baseline blood (n=172). We randomly selected controls among those who did not develop an event (n=344). Biomarkers were measured in a blinded batch analysis (Laboratory of the Medical University Clinic, Aarau, Switzerland, using B.R.A.H.M.S assays by Thermo Fisher Scientific). We calculated hazard ratios and 95% confidence intervals (HR, 95% CI) using Cox proportional hazards models, with inverse probability weighting to correct for the case-cohort study design, to estimate the association with risk of stroke after adjusting for demographic, behavioral, and medical risk factors.
Results:
Mean age of cases was 72 (IQR 65-78); 59% were female. After full adjustment, those with PCT in the top quartile, compared to the lowest quartile, were at increased risk of ischemic stroke (adjusted HR 1.98, 95% CI 1.02-3.83). Those with MRproANP levels in the top quartile, compared to the lowest quartile, were also at increased risk of stroke (adjusted HR 3.45, 95% CI 1.58-7.52), but not those with higher copeptin levels. The distribution of MRproANP differed by stroke etiology. Levels of MRproANP were greater for cardioembolic strokes (CE), and MRproANP levels were predictive of CE (adjusted HR 3.29 per SD, 95% CI 1.89-5.72).
Conclusion:
Higher levels of procalcitonin, a marker of infection, and MRproANP, a marker for hemodynamic stress, were independently associated with ischemic stroke risk in this multiethnic, urban cohort. MRproANP was specifically associated with cardioembolic stroke risk. Further study is needed to confirm these results
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Abstract W MP68: Brain Arterial Diameters and Risk of Vascular Events
Objective:
Inward and outward remodeling of cerebral vessels may represent alternate pathological vascular phenotypes. Our aim was to test whether extremes of brain arterial diameters increase risk of death and vascular events.
Methods:
Cerebral large artery diameters were measured in 1,034 stroke-free participants from Northern Manhattan. Arteries from the Circle of Willis (8) and posterior circulation (5) were measured in regions free of stenosis, adjusted for head size, standardized, and added to create a global measure of diameters in each person. Participants were categorized into the top 5% of the diameter distribution (âoutward remodelersâ) and bottom 5% (âinward remodelersâ), as well as an intermediate referent category (90% of population). We used logistic regression to calculate associations with risk factors and Cox models to calculate risks of outcomes after adjusting for demographic and vascular risk factors.
Results:
Mean follow-up was 5 ± 2 years. Inward remodelers were more likely to be men (OR 3.3, 95%CI 1.8-6.1) and less likely to be hypertensive (OR 0.5, 95%CI 0.3-0.9) or Hispanic (OR 0.3, 95%CI 0.2-0.6), while outward remodelers were more likely to be women (OR 14.6, 95%CI 3.5-60.5) and Hispanic (OR 8.7, 95%CI 1.2-65.0) compared to participants with less extreme diameters. Inward remodelers had a higher risk of death (HR 1.8, 95%CI 1.1-3.0), vascular death (HR 2.8, 95%CI 1.4-5.7), myocardial infarction (HR 2.5, 95%CI 1.0-6.4) and ischemic stroke (HR 3.4, 95%CI 1.0-10.2). Outward remodelers were not at increased risk of death or vascular events. Compared to those with less extreme diameters, risk of cardioembolic stroke was higher among inward remodelers (11.3 vs. 1.4%, HR 13.9, 95%CI 4.4-44.0) while strokes due to large or small artery disease were more frequent in outward remodelers (3.8 vs 1.8 %, HR 3.4, 95%CI 0.7-16.3).
Conclusions:
Individuals with the smallest brain arterial diameters are at greater risk of death, myocardial infarction, and ischemic stroke, while those with the largest brain arterial diameters were not. Cerebral arterial phenotypes might identify people at greater risk of cardiac disease and stroke, and direct targeting of primary preventive measures at likely stroke subtypes
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Perivascular spaces and cognitive performance in the Northern Manhattan Study
Background
Perivascular spaces (PVS) are fluidâfilled compartments surrounding brain small blood vessels, serving as conduits for fluid transport, exchange between CSF and interstitial fluid, and clearance of waste products. PVS are visible on MRI and associated with cerebral small vessel disease (SVD), and research is needed to understand their role as markers of SVD and potential contributors to vascular cognitive impairment. PVS have been reported in Alzheimer's disease, but less is known regarding their association with cognition in diverse populations. We tested the hypothesis that PVS are associated with cognition, independent of demographics and other markers of SVD, including white matter hyperintensity volume, silent brain infarcts, and cerebral microbleeds.
Method
We included 1,201 participants from the prospective Northern Manhattan Study. PVS were identified as parenchymal hypointensities <3mm on axial T1âweighted MRI without a hyperintense rim on T2âweighted or FLAIR images, that followed the orientation of perforating arteries. A semiquantitative PVS score represented the degree of brain involvement (range=0â28). Generalized linear models were used to assess associations with four cognitive domains (memory, executive function, processing speed, language) and global cognition (mean of domains) over two assessments carried out an average 6 years apart. Model 1 adjusted for demographics; Model 2 also included vascular risk factors; Model 3 also included burden of SVD.
Result
Among 1,201 participants (mean age=71±9 years; 60% women, 66% Hispanic, 18% Black, 10±5 years education; 68% with hypertension, 19% diabetes, 65% hypercholesterolemia), PVS scores ranged from 0â22 with 55% having a PVS score >4. PVS score was not associated with global cognition zâscore at first neuropsychological assessment, nor change in global cognitive performance between the two assessments. Higher PVS score was associated with worse processing speed at first assessment in models 1 and 2 (Model 2 beta=â0.015, p=0.01). A higher PVS score was associated with greater decline in memory, adjusting for demographics (model 1 beta=â0.015, p=0.01), but this relationship was attenuated and not significant after adjusting for modifiable vascular risk factors.
Conclusion
PVS are prevalent and associated with worse processing speed independent of age and vascular risk factors. Vascular risk factors largely explained variability in the association between PVS and memory decline
Procalcitonin and Midregional Proatrial Natriuretic Peptide as Biomarkers of Subclinical Cerebrovascular Damage
Background and purposeChronic infections and cardiac dysfunction are risk factors for stroke. We hypothesized that blood biomarkers of infection (procalcitonin) and cardiac dysfunction (midregional proatrial natriuretic peptide [MR-proANP]), previously associated with small vessel stroke and cardioembolic stroke are also associated with subclinical cerebrovascular damage, including silent brain infarcts and white matter hyperintensity volume.MethodsThe NOMAS (Northern Manhattan Study) was designed to assess risk factors for incident vascular disease in a multiethnic cohort. A subsample underwent brain magnetic resonance imaging and had blood samples available for biomarker measurement (n=1178). We used logistic regression models to estimate the odds ratios and 95% confidence intervals (95% CIs) for the association of these biomarkers with silent brain infarcts after adjusting for demographic, behavioral, and medical risk factors. We used linear regression to assess associations with log-white matter hyperintensity volume.ResultsMean age was 70±9 years; 60% were women, 66% Hispanic, 17% black, and 15% were white. After adjusting for risk factors, subjects with procalcitonin or MR-proANP in the top quartile, compared with the lowest quartile were more likely to have silent brain infarcts (adjusted odds ratio for procalcitonin, 2.2; 95% CI, 1.3-3.7 and for MR-proANP, 3.3; 95% CI, 1.7-6.3) and increased white matter hyperintensity volume (adjusted mean change in log-white matter hyperintensity volume for procalcitonin, 0.29; 95% CI, 0.13-0.44 and for MR-proANP, 0.18; 95% CI, 0.004-0.36).ConclusionsHigher concentrations of procalcitonin, a marker of infection, and MR-proANP, a marker of cardiac dysfunction, are independently associated with subclinical cerebrovascular damage. If further studies demonstrate an incremental value for risk stratification, biomarker-guided primary prevention studies may lead to new approaches to prevent cerebrovascular disease