HyperlipidemiasNCT00175084
Effect of Dietary Amino Acid Profile on Lipoprotein Metabolism, Vascular Reactivity and Inflammatory Markers
A study testing Comparison of dietary protein amino acid profile in people with Hyperlipidemias and Metabolic Syndrome X, run by Tufts University at 1 site in United States.
Trial summary
The aim of this study is to explore the significance of the Lys:Arg ratio on responses of lipids and lipoprotein concentrations to dietary proteins and to evaluate the effects of dietary Lys:Arg on cardiovascular disease risk factors and endothelial function. Read more about this study
- Who is it for?
- Ages 50 to 85 yearsHealthy volunteers can take part
- Conditions the study is for
- Hyperlipidemias, Metabolic Syndrome X, Cardiovascular Diseases
- What is being tested?
- Comparison of dietary protein amino acid profile
- Type of treatment
- Lifestyle or therapy programme
- How many people
- 30 participants
- Where
- 1 siteUnited States
- Study dates
- Oct 2004to Dec 2012
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 50 to 85 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Age: 50-85 years
- LDL-C concentrations >120 mg/dL
Who cannot join
- Use of medications known to affect lipid metabolism
- Established cardiovascular disease
- Renal disease
- Liver disease
- Thyroid disease unless controlled with medication for at least 6 months
- Type I and II diabetes
Show all 14Show fewer
- Irritable bowel syndrome
- Chronic use of prescription anti-inflammatory medications
- Smoking
- Alcohol intake >7 alcoholic drinks per week
- Unwillingness to maintain body weight during participation in the study
- triglyceride (TG) > 400 mg/dL
- Unwillingness to adhere to diet and study protocol
- Weight gain or loss of more than 15 lb within 6 months prior to enrollment
Trial locations and contacts
1 site in 1 country.
United States1 site
Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University
Boston, Massachusetts, 02111
About this study
The aim of this study is to explore the significance of the Lys:Arg ratio on responses of lipids and lipoprotein concentrations to dietary proteins and to evaluate the effects of dietary Lys:Arg on cardiovascular disease risk factors and endothelial function.
Read the detailed description
Findings from early studies in a variety of experimental models of atherosclerosis on the effect of dietary protein suggested that proteins from vegetable sources are less cholesterolemic and atherogenic than proteins from animal sources. Throughout the later part of the 20th century there has been sporadic interest in the effect of protein type and amino acid profiles on blood lipid concentrations and atherosclerosis. A major focus for this evaluation has been to compare proteins based on their amino acid profile, often expressed as lysine (Lys) to arginine (Arg) ratio (Lys:Arg). While animal studies have provided important information regarding the significance of the Lys:Arg in determining the cholesterolemic response to a dietary protein, interpretation of these data must be done with caution since most of the studies have been conducted in animal models that have a different lipoprotein distribution and metabolism than humans. Moreover, the mechanistic insights of this response are yet to be determined. While the favorable effects of Arg on endothelial function appear to be consistent when Arg is administered using a supplement, the effects of dietary Arg naturally present in protein rich foods has yet to be determined. The aim of this proposal is to explore the significance of the Lys:Arg ratio on responses of lipids and lipoprotein concentrations to dietary proteins and to evaluate the effects of dietary Lys:Arg on cardiovascular disease risk factors and endothelial function.
- Being tested
- Comparison of dietary protein amino acid profile
- Medical subject headings
- Hyperlipidemias, Metabolic Syndrome, Cardiovascular Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Comparison of dietary protein amino acid profileBehavioural
Healthy adults over 50 years of age (men and postmenopausal women) will be assigned to one of two diets differing in lysine to arginine ration (0.7 vs. 1.4) for a 5 week period and then switched to the alternate diet, with a 2 to 4-week washout period, in a randomized crossover design. Blood samples will be collected three times in the fasted state and once 4-hours after the evening meal during the last week of each dietary period of measurement of concentration of plasma lipids, lipoproteins, apolipoproteins, arginine, C-reactive protein, nitrites/nitrates, homocysteine, lecithin-cholesterol acetyltransferase (LCAT), cholesteryl ester transfer protein (CETP), and LDL-receptor messenger ribonucleic acid (mRNA) expression.A 24-hour urine sample will be collected at the end of each phase to measure F2-isoprostanes as an indicator of whole body oxidation.
What is being measured
The primary outcome is the main question the study is designed to answer.
Serum lipid and lipoprotein concentrations, endothelial function, blood pressure, indicators of nitrous oxide end products, homocysteine, inflammation and oxidation markers.
Measured: 5 week
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted15 Sep 2005 (estimated)
- Study startOct 2004
- Primary completionJun 2007
- Study completionDec 2012
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for HyperlipidemiasStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind
- Who is masked
- Investigator
- Enrolment
- 30 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Tufts University
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Alice H Lichtenstein, D.Sc., Principal investigator, Tufts Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00175084
- Sponsor's protocol ID
- HL58008-1188
- Status last verified
- May 2014
- First submitted
- 8 Sep 2005
- Last updated
- 23 May 2014
- Results posted
- No
- Data monitoring committee
- No
Study at a glance
From the registry record, last updated by the sponsor on 23 May 2014. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Dietary Amino Acid Profile on Lipoprotein Metabolism, Vascular Reactivity and Inflammatory Markers
- ClinicalTrials.gov ID
- NCT00175084
- Acronym / sponsor ID
- HL58008-1188
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 30 participants (estimated)
- Lead sponsor
- Tufts UniversityUniversity, hospital or other
- Study start
- Oct 2004
- Primary completion
- Jun 2007 (actual)
- Study completion
- Dec 2012 (actual)
- First posted
- 15 Sep 2005 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The aim of this study is to explore the significance of the Lys:Arg ratio on responses of lipids and lipoprotein concentrations to dietary proteins and to evaluate the effects of dietary Lys:Arg on cardiovascular disease risk factors and endothelial function.
Detailed description
Findings from early studies in a variety of experimental models of atherosclerosis on the effect of dietary protein suggested that proteins from vegetable sources are less cholesterolemic and atherogenic than proteins from animal sources. Throughout the later part of the 20th century there has been sporadic interest in the effect of protein type and amino acid profiles on blood lipid concentrations and atherosclerosis. A major focus for this evaluation has been to compare proteins based on their amino acid profile, often expressed as lysine (Lys) to arginine (Arg) ratio (Lys:Arg). While animal studies have provided important information regarding the significance of the Lys:Arg in determining the cholesterolemic response to a dietary protein, interpretation of these data must be done with caution since most of the studies have been conducted in animal models that have a different lipoprotein distribution and metabolism than humans. Moreover, the mechanistic insights of this response are yet to be determined. While the favorable effects of Arg on endothelial function appear to be consistent when Arg is administered using a supplement, the effects of dietary Arg naturally present in protein rich foods has yet to be determined. The aim of this proposal is to explore the significance of the Lys:Arg ratio on responses of lipids and lipoprotein concentrations to dietary proteins and to evaluate the effects of dietary Lys:Arg on cardiovascular disease risk factors and endothelial function.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (investigator)
Who may qualify
- Ages
- 50 to 85 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- Age: 50-85 years
- LDL-C concentrations >120 mg/dL
Key exclusion criteria (14 listed)
- Use of medications known to affect lipid metabolism
- Established cardiovascular disease
- Renal disease
- Liver disease
- Thyroid disease unless controlled with medication for at least 6 months
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Comparison of dietary protein amino acid profileHealthy adults over 50 years of age (men and postmenopausal women) will be assigned to one of two diets differing in lysine to arginine ration (0.7 vs. 1.4) for a 5 week period and then switched to the alternate diet, with a 2 to 4-week washout period, in a randomized crossover design. Blood samples will be collected three times in the fasted state and once 4-hours after the evening meal during the last week of each dietary period of measurement of concentration of plasma lipids, lipoproteins, apolipoproteins, arginine, C-reactive protein, nitrites/nitrates, homocysteine, lecithin-cholesterol acetyltransferase (LCAT), cholesteryl ester transfer protein (CETP), and LDL-receptor messenger ribonucleic acid (mRNA) expression.A 24-hour urine sample will be collected at the end of each phase to measure F2-isoprostanes as an indicator of whole body oxidation. | Behavioural | – |
Primary outcome
Serum lipid and lipoprotein concentrations, endothelial function, blood pressure, indicators of nitrous oxide end products, homocysteine, inflammation and oxidation markers.
Time frame: 5 week
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 May 2014.
- Click here for more information about this study:Link provided by the sponsor.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Alice H Lichtenstein, D.Sc. principal investigator
Tufts Medical Center
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Comparison of dietary protein amino acid profile in people with Hyperlipidemias and Metabolic Syndrome X, run by Tufts University at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 14 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 23 May 2014. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Serum lipid and lipoprotein concentrations, endothelial function, blood pressure, indicators of nitrous oxide end products, homocysteine, inflammation and oxidation markers. (time frame: 5 week). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 23 May 2014.