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Effects of Walnuts on Endothelial Function in Overweight Adults With at Least One Factor of Metabolic Syndrome (Walnut2)

Primary Purpose

Metabolic Syndrome

Status

Completed

Phase

Not Applicable

Locations

United States

Study Type

Interventional

Intervention

Walnut Supplementation

No walnut supplementation

About this trial

This is an interventional prevention trial for Metabolic Syndrome focused on measuring obesity, walnuts, endothelial function

Eligibility Criteria

25 Years - 75 Years (Adult, Older Adult)All SexesDoes not accept healthy volunteers

Inclusion Criteria:

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.

Exclusion Criteria:

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
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

Sites / Locations

Yale-Griffin Prevention Research Center

Arms of the Study

Arm 1

Arm 2

Arm Type

Experimental

Placebo Comparator

Arm Label

Walnut Supplementation

Arm Description

Eight weeks with walnut supplementation to an ad lib diet

Eight weeks ad lib diet without walnut supplementation

Outcomes

Primary Outcome Measures

Endothelial function

Brachial artery flow mediated dilation (FMD)

Secondary Outcome Measures

Weight

Waist circumference

Fasting lipid panel

Total cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol, triglyceride level, cholesterol / high density lipoprotein cholesterol ratio

Fasting blood glucose

Fasting insulin

Blood pressure

Full Information

NCT ID

NCT01413646

First Posted

July 11, 2011

Last Updated

July 31, 2019

Sponsor

Griffin Hospital

Collaborators

California Walnut Commission

1. Study Identification

Unique Protocol Identification Number

NCT01413646

Brief Title

Effects of Walnuts on Endothelial Function in Overweight Adults With at Least One Factor of Metabolic Syndrome

Acronym

Walnut2

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

Study Type

Interventional

2. Study Status

Record Verification Date

July 2019

Overall Recruitment Status

Completed

Study Start Date

February 2010 (undefined)

Primary Completion Date

October 2010 (Actual)

Study Completion Date

December 2010 (Actual)

3. Sponsor/Collaborators

Responsible Party, by Official Title

Principal Investigator

Name of the Sponsor

Griffin Hospital

Collaborators

California Walnut Commission

4. Oversight

Data Monitoring Committee

5. Study Description

Brief 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.

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.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study

Metabolic Syndrome

Keywords

obesity, walnuts, endothelial function

7. Study Design

Primary Purpose

Prevention

Study Phase

Not Applicable

Interventional Study Model

Crossover Assignment

Masking

None (Open Label)

Allocation

Randomized

Enrollment

40 (Actual)

8. Arms, Groups, and Interventions

Arm Title

Walnut Supplementation

Arm Type

Experimental

Arm Description

Eight weeks with walnut supplementation to an ad lib diet

Arm Title

Arm Type

Placebo Comparator

Arm Description

Eight weeks ad lib diet without walnut supplementation

Intervention Type

Dietary Supplement

Intervention Name(s)

Walnut Supplementation

Intervention Description

Eight weeks of walnut supplementation

Intervention Type

Dietary Supplement

Intervention Name(s)

No walnut supplementation

Intervention Description

Eight weeks without walnut supplementation

Primary Outcome Measure Information:

Title

Endothelial function

Description

Brachial artery flow mediated dilation (FMD)

Time Frame

8 weeks

Secondary Outcome Measure Information:

Title

Weight

Time Frame

8 weeks

Title

Waist circumference

Time Frame

8 weeks

Title

Fasting lipid panel

Description

Total cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol, triglyceride level, cholesterol / high density lipoprotein cholesterol ratio

Time Frame

8 weeks

Title

Fasting blood glucose

Time Frame

8 weeks

Title

Fasting insulin

Time Frame

8 weeks

Title

Blood pressure

Time Frame

8 weeks

10. Eligibility

Sex

All

Minimum Age & Unit of Time

25 Years

Maximum Age & Unit of Time

75 Years

Accepts Healthy Volunteers

Eligibility Criteria

Inclusion Criteria: 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. Exclusion Criteria: 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 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

Overall Study Officials:

First Name & Middle Initial & Last Name & Degree

David L. Katz, MD, MPH

Organizational Affiliation

Yale-Griffin Prevention Research Center

Official's Role

Principal Investigator

Facility Information:

Facility Name

Yale-Griffin Prevention Research Center

City

Derby

State/Province

Connecticut

ZIP/Postal Code

06418

Country

United States

12. IPD Sharing Statement

Citations:

PubMed Identifier

23756586

Citation

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.

Results Reference

derived

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Effects of Walnuts on Endothelial Function in Overweight Adults With at Least One Factor of Metabolic Syndrome

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