Metabolic SyndromeWalnut2NCT01413646
Effects of Walnuts on Endothelial Function in Overweight Adults With at Least One Factor of Metabolic Syndrome
A study testing Walnut Supplementation and No walnut supplementation in people with Metabolic Syndrome, run by Griffin Hospital at 1 site in United States.
Trial summary
The purpose of this study is to examine the effects of walnut consumption on endothelial function and lipid markers in overweight patients with at least one factor of metabolic syndrome as compared to the control group. Read more about this study
- Who is it for?
- Ages 25 to 75 years
- Conditions the study is for
- Metabolic Syndrome
- What is being tested?
- Walnut Supplementation and No walnut supplementation
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 40 participants
- Where
- 1 siteUnited States
- Study dates
- Feb 2010to Dec 2010
- 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 25 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Male and female age 25-75 years
- Non-smoker
- Overweight (BMI ≥ 25) with central adiposity as indicated by waist circumference (102 cm. in men / 88 cm. in women)
- Meet one risk factor of the metabolic syndrome.
- blood pressure > 130/85 or taking antihypertensive medication
- fasting plasma glucose (FPG) >100 mg/dL (6.1 mmol/L)
- fasting serum triglycerides level (TG) > 150 mg/dL (1.69 mmol/L)
- fasting high-density lipoprotein (HDL) cholesterol < 40 mg/dL (1.04 mmol/L)in men, and < 50 mg/dL (1.29 mmol/L) in women.
Who cannot join
- Anticipated inability to complete or comply with study protocol
- Use of lipid-lowering or antihypertensive medications or aspirin unless stable on medication for at least 3 months and willing to refrain from taking medication for 12 hours prior to EF scanning
- Preexisting cardiovascular disease (including symptomatic coronary artery disease (CAD), myocardial infarction, angina pectoris, anginal equivalent, peripheral vascular disease, congestive heart failure, carotid stenosis)
- Severe hypertension (systolic blood pressure >180mmHg or diastolic blood pressure >105mmHg), even if well-controlled by medication.
- Diagnosed diabetes mellitus
- Regular use of multivitamins, Vitamin C, Vitamin E, fish oil, flax seed oil, omega-3 fatty acids, CoQ10, fiber supplements, garlic pills, arginine, red yeast rice, and any kind of antioxidant and unwillingness to discontinue supplementation for at least 4 weeks prior to study initiation and for study duration
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- Allergic to walnuts or any other nuts
- Diagnosed eating disorder
- On any specific diet, weight control diet, vegan diet
- Any rheumatologic disease requiring regular use of NSAIDs or alternative medications
- Regular use of fiber supplements
- Regular use of vasoactive medication (including glucocorticoids, antineoplastic agents, psychoactive agents, or bronchodilators), and anticoagulant drugs (including Coumadin, plavix )
- Diagnosed sleep apnea
- Substance abuse (chronic alcoholism, other chemical dependency)
- Any unstable medical condition that would limit the ability of a subject to participate fully in the trial (e.g., cancer, AIDS, tuberculosis, psychotic disorder)
- Current or impending pregnancy
Trial locations and contacts
1 site in 1 country.
United States1 site
Yale-Griffin Prevention Research Center
Derby, Connecticut, 06418
About this study
Official title: Effects of Walnuts on Endothelial Function in Overweight Adults With at Least One Factor of Metabolic Syndrome: A Randomized, Controlled, Cross-Over Trial
The purpose of this study is to examine the effects of walnut consumption on endothelial function and lipid markers in overweight patients with at least one factor of metabolic syndrome as compared to the control group.
Read the detailed description
The prevalence of obesity in both adults and children in the United States has increased significantly over the past 50 years. More than 66% of adults in the US are now overweight or obese and at least 17% of children in the population at large are now considered overweight.Obesity may be a factor predisposing patients to a myriad of comorbidities that increase the associated mortality rate.Several large prospective trials have documented that obesity is an independent risk factor for mortality from cardiovascular disease (CVD). Considering the major metabolic and biochemical changes that occur in obesity, such as atherogenic dyslipidemia, insulin resistance and hyperinsulinemia, endothelial dysfunction, and chronic inflammatory and prothrombotic states, obesity plays a role in the pathogenesis of systemic atherosclerosis and its clinical complications.
Walnuts are rich in alpha-linolenic acid, an essential omega-3 fatty acid, L-arginine and antioxidants. Polyunsaturated fatty acids and antioxidants have anti-oxidative effects and are thought to help preserve the endothelium's capacity to generate nitric oxide (NO), which acts to promote vasodilation, stabilize platelets, and promote the anti-inflammatory abilities of the endothelium. Evidence of this anticipated effect would have implications for strategies to prevent or retard type 2 diabetes mellitus and cardiovascular disease. Endothelial function testing using high frequency ultrasound imaging of the brachial artery to assess endothelium-dependent flow-mediated dilatation (FMD) offers a non-invasive, uniquely valuable means of assessing aggregated influences on cardiac risk by gauging a physiologic response of the vascular endothelium. Proposed, therefore, is a randomized, controlled, cross-over clinical trial, to assess the effects of walnuts on endothelial function in overweight adults with elevated waist circumference and at least one risk factor of metabolic syndrome.
- Conditions
- Metabolic Syndrome
- Being tested
- Walnut Supplementation, No walnut supplementation
- Keywords
- obesity, walnuts, endothelial function
- Medical subject headings
- Metabolic Syndrome, Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Walnut SupplementationDietary supplement
Eight weeks of walnut supplementation
No walnut supplementationDietary supplement
Eight weeks without walnut supplementation
| Study group | Role | What they receive |
|---|---|---|
| Walnut Supplementation | Experimental | Eight weeks with walnut supplementation to an ad lib diet Receives: Dietary Supplement: Walnut Supplementation |
| 2 | Placebo comparator | Eight weeks ad lib diet without walnut supplementation Receives: Dietary Supplement: No walnut supplementation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Endothelial function
Brachial artery flow mediated dilation (FMD)
Measured: 8 weeks
Secondary outcomes (6)
Weight
Measured: 8 weeks
Waist circumference
Measured: 8 weeks
Fasting lipid panel
Total cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol, triglyceride level, cholesterol / high density lipoprotein cholesterol ratio
Measured: 8 weeks
Fasting blood glucose
Measured: 8 weeks
Fasting insulin
Measured: 8 weeks
Blood pressure
Measured: 8 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Aug 2011 (estimated)
- Study startFeb 2010
- Primary completionOct 2010
- Study completionDec 2010
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Metabolic SyndromeStudies 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
- None (open label)
- Enrolment
- 40 participants (actual)
Sponsor and investigators
- Lead sponsor
- Griffin Hospital
- Sponsor type
- University, hospital or other
- Collaborators
- California Walnut Commission
- Responsible party
- Principal investigator, David Katz, MD, Griffin Hospital
- Investigators
- David L. Katz, MD, MPH, Principal investigator, Yale-Griffin Prevention Research Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01413646
- Sponsor's protocol ID
- 2009-15
- Acronym
- Walnut2
- Status last verified
- Jul 2019
- First submitted
- 11 Jul 2011
- Last updated
- 2 Aug 2019
- Results posted
- No
- Data monitoring committee
- No
Publications
Katz DL, Davidhi A, Ma Y, Kavak Y, Bifulco L, Njike VY. Effects of walnuts on endothelial function in overweight adults with visceral obesity: a randomized, controlled, crossover trial. J Am Coll Nutr. 2012 Dec;31(6):415-23. doi: 10.1080/07315724.2012.10720468.
PubMed 23756586
Study at a glance
From the registry record, last updated by the sponsor on 2 Aug 2019. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Walnuts on Endothelial Function in Overweight Adults With at Least One Factor of Metabolic Syndrome: A Randomized, Controlled, Cross-Over Trial
- ClinicalTrials.gov ID
- NCT01413646
- Acronym / sponsor ID
- Walnut2 / 2009-15
- Conditions
- Metabolic Syndrome
- Keywords
- obesity, walnuts, endothelial function
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 40 participants (actual)
- Lead sponsor
- Griffin HospitalUniversity, hospital or other
- Collaborators
- California Walnut Commission
- Study start
- Feb 2010
- Primary completion
- Oct 2010 (actual)
- Study completion
- Dec 2010 (actual)
- First posted
- 10 Aug 2011 (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 purpose of this study is to examine the effects of walnut consumption on endothelial function and lipid markers in overweight patients with at least one factor of metabolic syndrome as compared to the control group.
Detailed description
The prevalence of obesity in both adults and children in the United States has increased significantly over the past 50 years. More than 66% of adults in the US are now overweight or obese and at least 17% of children in the population at large are now considered overweight.Obesity may be a factor predisposing patients to a myriad of comorbidities that increase the associated mortality rate.Several large prospective trials have documented that obesity is an independent risk factor for mortality from cardiovascular disease (CVD). Considering the major metabolic and biochemical changes that occur in obesity, such as atherogenic dyslipidemia, insulin resistance and hyperinsulinemia, endothelial dysfunction, and chronic inflammatory and prothrombotic states, obesity plays a role in the pathogenesis of systemic atherosclerosis and its clinical complications.
Walnuts are rich in alpha-linolenic acid, an essential omega-3 fatty acid, L-arginine and antioxidants. Polyunsaturated fatty acids and antioxidants have anti-oxidative effects and are thought to help preserve the endothelium's capacity to generate nitric oxide (NO), which acts to promote vasodilation, stabilize platelets, and promote the anti-inflammatory abilities of the endothelium. Evidence of this anticipated effect would have implications for strategies to prevent or retard type 2 diabetes mellitus and cardiovascular disease. Endothelial function testing using high frequency ultrasound imaging of the brachial artery to assess endothelium-dependent flow-mediated dilatation (FMD) offers a non-invasive, uniquely valuable means of assessing aggregated influences on cardiac risk by gauging a physiologic response of the vascular endothelium. Proposed, therefore, is a randomized, controlled, cross-over clinical trial, to assess the effects of walnuts on endothelial function in overweight adults with elevated waist circumference and at least one risk factor of metabolic syndrome.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Walnut Supplementation | Experimental | Dietary Supplement: Walnut SupplementationEight weeks with walnut supplementation to an ad lib diet |
| 2 | Placebo comparator | Dietary Supplement: No walnut supplementationEight weeks ad lib diet without walnut supplementation |
Who may qualify
- Ages
- 25 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (8 listed)
- Male and female age 25-75 years
- Non-smoker
- Overweight (BMI ≥ 25) with central adiposity as indicated by waist circumference (102 cm. in men / 88 cm. in women)
- Meet one risk factor of the metabolic syndrome.
Key exclusion criteria (16 listed)
- Anticipated inability to complete or comply with study protocol
- Use of lipid-lowering or antihypertensive medications or aspirin unless stable on medication for at least 3 months and willing to refrain from taking medication for 12 hours prior to EF scanning
- Preexisting cardiovascular disease (including symptomatic coronary artery disease (CAD), myocardial infarction, angina pectoris, anginal equivalent, peripheral vascular disease, congestive heart failure, carotid stenosis)
- Severe hypertension (systolic blood pressure >180mmHg or diastolic blood pressure >105mmHg), even if well-controlled by medication.
- Diagnosed diabetes mellitus
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 |
|---|---|---|
| Walnut SupplementationEight weeks of walnut supplementation | Dietary supplement | Walnut Supplementation |
| No walnut supplementationEight weeks without walnut supplementation | Dietary supplement | 2 |
Primary outcome
Endothelial function
Time frame: 8 weeks
Brachial artery flow mediated dilation (FMD)
6 secondary outcomes
Weight
Time frame: 8 weeks
Waist circumference
Time frame: 8 weeks
Fasting lipid panel
Time frame: 8 weeks
Fasting blood glucose
Time frame: 8 weeks
Fasting insulin
Time frame: 8 weeks
Blood pressure
Time frame: 8 weeks
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 2 Aug 2019.
- Derived from this study: PubMed 23756586Katz DL, Davidhi A, Ma Y, Kavak Y, Bifulco L, Njike VY. Effects of walnuts on endothelial function in overweight adults with visceral obesity: a randomized, controlled, crossover trial. J Am Coll Nutr. 2012 Dec;31(6):415-23. doi: 10.1080/07315724.2012.10720468.
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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.
David L. Katz, MD, MPH principal investigator
Yale-Griffin Prevention Research 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 Walnut Supplementation and No walnut supplementation in people with Metabolic Syndrome, run by Griffin Hospital 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 8 inclusion and 16 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 2 Aug 2019. 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. Some participants in this study may receive a placebo. 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?
Endothelial function (time frame: 8 weeks). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT01413646, which also lists 1 linked publication.
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 2 Aug 2019.