Ignite Creation Date:
2024-05-05 @ 11:21 AM
Last Modification Date:
2024-10-26 @ 9:05 AM
Study NCT ID:
NCT00005372
Status:
COMPLETED
Last Update Posted:
2016-01-20
First Post:
2000-05-25
Brief Title:
Intimal Thickening and Antioxidants in Hispanics and Anglos Los Angeles Atherosclerosis Study
Sponsor:
University of Southern California
Organization:
University of Southern California
Study Overview
Official Title:
None
Status:
COMPLETED
Status Verified Date:
2016-01
Last Known Status:
None
Delayed Posting:
No
If Stopped, Why?:
Not Stopped
Has Expanded Access:
False
If Expanded Access, NCT#:
N/A
Has Expanded Access, NCT# Status:
N/A
Acronym:
None
Brief Summary:
To investigate the role of serum and dietary antioxidants serum pro-oxidants and smoking on the progressionregression of carotid intima-media thickness IMT
Detailed Description:
BACKGROUND
A finding from the Cholesterol Lowering Atherosclerosis Study CLAS a clinical trial indicated that common carotid intima-media thickness responded more rapidly and more markedly to LDL-C lowering treatment than angiographic coronary stenosis or carotid roughness New data from a primate model also showed ultrasound detection of intimal thickening in response to a hypercholesterolemic diet within twelve months These findings suggest that carotid IMT is a reliable and rapidly responding marker of extent of atherosclerosis However less than a third of the observed therapeutic benefit on carotid IMT found in CLAS was explained by change in LDL-C and HDL-C suggesting that related or other factors are more directly linked to atherogenic mechanisms In addition a Finnish epidemiologic study found that LDL-C was predicative of rate of progression in carotid IMT only in persons with high serum levels of pro-oxidant copper These and other data support a model of atherosclerosis in which intracellular accumulation of modified LDL is promotedretarded by serum pro-oxidantsantioxidants
DESIGN NARRATIVE
The study tested the specific hypotheses that the positive association between rate of increase in carotid IMT and low density lipoprotein cholesterol beta deltaIMTLDL was greater in persons with 1 higher levels of serum pro-oxidants relative to persons with lower levels of serum pro-oxidants 2 lower levels of serum antioxidants 3 lower levels of dietary antioxidants and 4 that regression of carotid IMT associated with smoking cessation would be detected in 30 months Hypothesis were tested with the longitudinal observation of carotid IMT in Hispanic and non-Hispanic white women and men The inclusion of Hispanics and women was motivated by their prevalence in the study population 18 percent Hispanic 40 percent women and by the then recent report that incidence of hospitalization for myocardial infarction was elevated in Hispanics Seventy three persons from each of four ethnicity-sex groups aged 40-60 years n-292 and 83 smokers and recent quitters n-166 were recruited from employees in an ongoing study Baseline blood diet and potential confounder variables were related to 18 and 36 month 6 12 18 24 and 30 month in smokers changes in carotid IMT Levels of antioxidant vitamins including alpha-tocopherol ascorbate and beta carotene in the plasma were measured at baseline Plasma levels of negatively charged LDL were measured in a sub-sample of subjects with the most rapidly progressing common carotid intima-media thickness and in an age-sex matched subsample with the least rapidly progressing common carotid intima-media thickness Finally an ultrasound measurement of carotid arterial stiffness another indicator of early atherosclerosis was developed to address the role of blood pressure
The Los Angeles Atherosclerosis Study LAAS has been renewed through February 2004 to continue follow-up of the cohort for a total of seven years with two additional measures of arterial dysfunction including endothelial function of the brachial artery and distensibility or stiffness of the common carotid artery
A finding from the Cholesterol Lowering Atherosclerosis Study CLAS a clinical trial indicated that common carotid intima-media thickness responded more rapidly and more markedly to LDL-C lowering treatment than angiographic coronary stenosis or carotid roughness New data from a primate model also showed ultrasound detection of intimal thickening in response to a hypercholesterolemic diet within twelve months These findings suggest that carotid IMT is a reliable and rapidly responding marker of extent of atherosclerosis However less than a third of the observed therapeutic benefit on carotid IMT found in CLAS was explained by change in LDL-C and HDL-C suggesting that related or other factors are more directly linked to atherogenic mechanisms In addition a Finnish epidemiologic study found that LDL-C was predicative of rate of progression in carotid IMT only in persons with high serum levels of pro-oxidant copper These and other data support a model of atherosclerosis in which intracellular accumulation of modified LDL is promotedretarded by serum pro-oxidantsantioxidants
DESIGN NARRATIVE
The study tested the specific hypotheses that the positive association between rate of increase in carotid IMT and low density lipoprotein cholesterol beta deltaIMTLDL was greater in persons with 1 higher levels of serum pro-oxidants relative to persons with lower levels of serum pro-oxidants 2 lower levels of serum antioxidants 3 lower levels of dietary antioxidants and 4 that regression of carotid IMT associated with smoking cessation would be detected in 30 months Hypothesis were tested with the longitudinal observation of carotid IMT in Hispanic and non-Hispanic white women and men The inclusion of Hispanics and women was motivated by their prevalence in the study population 18 percent Hispanic 40 percent women and by the then recent report that incidence of hospitalization for myocardial infarction was elevated in Hispanics Seventy three persons from each of four ethnicity-sex groups aged 40-60 years n-292 and 83 smokers and recent quitters n-166 were recruited from employees in an ongoing study Baseline blood diet and potential confounder variables were related to 18 and 36 month 6 12 18 24 and 30 month in smokers changes in carotid IMT Levels of antioxidant vitamins including alpha-tocopherol ascorbate and beta carotene in the plasma were measured at baseline Plasma levels of negatively charged LDL were measured in a sub-sample of subjects with the most rapidly progressing common carotid intima-media thickness and in an age-sex matched subsample with the least rapidly progressing common carotid intima-media thickness Finally an ultrasound measurement of carotid arterial stiffness another indicator of early atherosclerosis was developed to address the role of blood pressure
The Los Angeles Atherosclerosis Study LAAS has been renewed through February 2004 to continue follow-up of the cohort for a total of seven years with two additional measures of arterial dysfunction including endothelial function of the brachial artery and distensibility or stiffness of the common carotid artery
Study Oversight
Has Oversight DMC:
Is a FDA Regulated Drug?:
Is a FDA Regulated Device?:
Is an Unapproved Device?:
Is a PPSD?:
Is a US Export?:
Is an FDA AA801 Violation?:
Secondary IDs
| Secondary ID | Type | Domain | Link |
|---|---|---|---|
| R01HL049910 | NIH | None | httpsreporternihgovquickSearchR01HL049910 |