Clinical Trial Details
— Status: Completed
Administrative data
NCT number |
NCT03266952 |
Other study ID # |
20070212 |
Secondary ID |
R37NS029993 |
Status |
Completed |
Phase |
|
First received |
|
Last updated |
|
Start date |
January 1993 |
Est. completion date |
December 2022 |
Study information
Verified date |
January 2023 |
Source |
University of Miami |
Contact |
n/a |
Is FDA regulated |
No |
Health authority |
|
Study type |
Observational
|
Clinical Trial Summary
Enrollment of a population-based, prospective cohort of 3298 stroke-free adults was completed
in 2001 and annual follow-up has continued since then. This collaborative study is the first
prospective cohort study among whites, blacks and Caribbean Hispanics living in the same
community. This grant supports continued follow-up and outcome detection and expansion of
data collection in this cohort. The aims are to evaluate the relationship between vascular
outcomes (stroke, myocardial infarction (MI), and vascular death) and insulin resistance,
carotid intima-media thickness, carotid distensibility, and quantitative magnetic resonance
imaging (MRI) measures of vascular subclinical brain disease and to determine if MRI
subclinical disease accounts for race/ethnic differences in cognitive impairment. To
accomplish these aims further data collection using the population-based, prospective cohort
study is proposed. Stored baseline serum will be used to measure fasting insulin levels to
evaluate insulin resistance. High-resolution carotid imaging data will be collected at
subsequent visits to expand the measurements of subclinical carotid disease to 1300 subjects.
MRIs and a neuropsychological battery emphasizing frontal executive domains will be done on
1300 subjects and quantitative analyses performed to measure white matter hyperintensities,
silent infarcts, and silent cerebral microbleeds.
Starting in 2005, subjects enrolled in the MRI substudy began to have echocardiograms and
24hour ambulatory blood pressure monitoring. Subjects will be followed by annual telephone
interviews to ascertain stroke, MI, death, and changes in cognitive state. In-person
assessment will be done for all subjects who screen positive. Community stroke surveillance
will be maintained to insure stroke detection among the cohort. Specific diagnostic
committees classify stroke, MI and vascular death.
Description:
Stroke remains a major public health problem with a disproportionate impact on blacks and
Hispanics.
Studies in Northern Manhattan have demonstrated that blacks and Hispanics have a greater
stroke incidence and more frequently have small vessel and intracranial atherosclerotic
stroke than whites.
The reasons for these race/ethnic disparities are not entirely clear. Enrollment of a
population-based, prospective cohort of 3298 stroke-free adults was completed in 2001 and
annual followup has continued since then. This collaborative study is the first prospective
cohort study among whites, blacks and Caribbean Hispanics living in the same community. This
grant supports continued followup and outcome detection and expansion of data collection in
this cohort. The aims are to evaluate the relationship between vascular outcomes (stroke, MI,
and vascular death) and insulin resistance, carotid intima-media thickness, carotid
distensibility, and quantitative MRI measures of vascular subclinical brain disease and to
determine if MRI subclinical disease accounts for race/ethnic differences in cognitive
impairment. To accomplish these aims further data collection using the population-based,
prospective cohort study is proposed. Stored baseline serum will be used to measure fasting
insulin levels to evaluate insulin resistance. High resolution carotid imaging data will be
collected at subsequent visits to expand the measurements of subclinical carotid disease to
1300 subjects. MRIs and a neuropsychological battery emphasizing frontal executive domains
will be done on 1300 subjects and quantitative analyses performed to measure white matter
hyperintensities, silent infarcts, and silent cerebral microbleeds.
Starting in 2005, subjects enrolled in the MRI substudy began to have echocardiograms and
24hour ambulatory blood pressure monitoring. Subjects will be followed by annual telephone
interviews to ascertain stroke, MI, death, and changes in cognitive state. In-person
assessment will be done for all subjects who screen positive. Community stroke surveillance
will be maintained to insure stroke detection among the cohort. Specific diagnostic
committees classify stroke, MI and vascular death. The strengths of this cohort study are the
wealth of baseline data already assembled, the triethnic composition residing in the same
community, the outstanding followup record, the evaluation of putative risk factors, and the
innovative assessment of MRI subclinical disease and carotid subclinical disease. The study
primary hypotheses are:1. To determine the independent association of insulin resistance
among nondiabetics and the incidence of stroke, as well as stroke, MI or vascular death,
after adjusting for known modifiable risk factors such as hypertension, lipids, cigarettes,
and alcohol. 2.
To evaluate the independent association of subclinical carotid disease (carotid intima-media
thickness and carotid distensibility) and the incidence of stroke, MI or vascular death after
adjusting for conventional modifiable vascular risk factors, as well as novel vascular risk
factors such as homocysteine, high density lipoprotein (HDL) subpopulations, and insulin
resistance.3. To compare the prevalence of subclinical vascular brain disease as measured by
quantitative MRI, including white matter hyperintensities, silent infarcts, and silent
cerebral microbleeds, in each race/ethnic subgroup and determine the association between
subclinical brain disease and modifiable vascular risk factors measured up to 10 years prior
to MRI. Vascular risk factors will include baseline and repeated measures of conventional
modifiable conditions such as hypertension, diabetes, lipid levels, cigarette smoking,
physical activity, alcohol use, as well as less-well documented factors such as homocysteine,
HDL subpopulations, and insulin resistance. 4. To determine the relationship between
subclinical vascular brain diseases and cognitive impairment, particularly diminished
performance in frontal executive tests, and whether these MRI findings help explain cognitive
performance differences among whites, blacks and Hispanics after adjusting for age and
education.5. To explore whether subclinical vascular brain diseases are important predictors
of stroke, MI or vascular death. Beginning in Summer 2005, some new aims were added as
follows: 1) to determine whether aortic arch abnormalities and/or cardiac abnormalities,
and/or 24hour blood pressure levels and changes, are independently associated with silent
brain infarcts in the elderly; 2) to determine the risk of symptomatic stroke, myocardial
infarction and vascular death associated with aortic/cardiac/24hour blood pressure
abnormalities. As of 2010 the investigators will be collaborating with other institutions
under the NINDS Ischemic Stroke Genetics (ISG) study. The aims of the NINDS Ischemic Stroke
Genetics Study (NINDS ISG Study; NIH Grant 1 U01 NS06920801) are to:1) Assemble ischemic
stroke phenotypic data and high quality DNA data from 10 stroke studies. (Participating
studies in the NINDS ISG Study: Ischemic Stroke Genetics Study; Siblings with Ischemic Stroke
Study; Greater Cincinnati/Northern Kentucky Stroke Study; Genes Affecting Stroke Risk and
Outcome Study/Bugher Network Study; Northern Manhattan Study; Baltimore/Washington Young
Stroke Study; Heart and Vascular Health Stroke Study; Nurses Health Study; Reasons for
Geographic and Racial Differences in Stroke; Women's Health Initiative). This collaboration
has access to 7,033 cases of ischemic stroke and 23,411 study-specific controls. 2) Test for
associations with ischemic stroke and its subtypes in the NINDS ISG Study. 3) Replicate and
extend associations detected in Aim 1.2 above by taking advantage of other genomewide
association studies conducted by other members of the Ischemic Stroke Genetics studies.