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Effects of Walnut Consumption on Endothelial Function in Type 2 Diabetes (WALNUT)

Primary Purpose

DIABETES MELLITUS TYPE 2

Status

Completed

Phase

Not Applicable

Locations

United States

Study Type

Interventional

Intervention

Walnut supplementation

Ad lib diet

About this trial

This is an interventional treatment trial for DIABETES MELLITUS TYPE 2

Eligibility Criteria

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

Inclusion Criteria:

men and women ages 35-75
non-smoker
able to have blood pressure taken bilaterally
diagnosed with type 2 diabetes by physician for at least one year
stable glucose levels and medication dose for the past 3 months
not on insulin therapy

Exclusion Criteria:

failure to meet inclusion criteria
anticipated inability to complete or comply with study protocol for any reason (e.g., inability to communicate in English, dementia) or any unstable medical condition that would limit the ability of a subject to participate fully in the trial (e.g., wasting illness, AIDS, tuberculosis, psychotic disorder)
diagnosed eating disorder
use of lipid-lowering or antihypertensive medications (statins, red rice yeast extract, garlic) unless stable on medication for at least 3 months and willing to refrain from taking medication for 12 hours prior to endothelial function (EF) scanning, vasoactive medication (i.e., glucocorticoids, antineoplastic agents, psychoactive agents, or bronchodilators) or nutriceuticals
regular use of multivitamins and/or complementary or alternative supplement therapy and unwillingness to discontinue supplementation for at least 8 weeks prior to study initiation and for study duration
any rheumatologic disease requiring regular use of nonsteroidal antiinflammatory drug (NSAIDs) or alternative medications
regular use of fiber supplements
preexisting cardiovascular disease, including symptomatic coronary artery disease (CAD), myocardial infarction, angina pectoris, anginal equivalent, peripheral vascular disease (claudication, amputation, or revascularization) congestive heart failure, carotid stenosis, aortic stenosis or stroke; diabetes, sleep apnea, severe uncontrolled hypertension (systolic blood pressure > 180 mmHg or diastolic blood pressure > 105 mmHg)
coagulopathy, known bleeding diathesis or history of clinically significant hemorrhage; current use of warfarin
clinically significant anemia (Hct < 36% in men, < 33% in women)
intestinal or stomach disease
inability to use right or left arm for endothelial function testing for any reason such as breast surgery, trauma, radiation to right axilla, lymphedema, right arm shunt, severe vascular disease in right arm
subjects on a disease specific diet
subjects on a weight control diet
subjects on a vegan diet
allergy to any kind of nut, including walnuts and peanuts

Sites / Locations

Griffin Hospital

Arms of the Study

Arm 1

Arm 2

Arm Type

Experimental

Active Comparator

Arm Label

Walnut supplementation

Ad lib diet

Arm Description

Eight weeks with walnut supplementation to an ad lib diet

Eight weeks ad lib diet without walnut supplementation

Outcomes

Primary Outcome Measures

Brachial artery flow mediated dilation (FMD)

Secondary Outcome Measures

Change in weight, waist circumference, blood pressure, fasting lipids, fasting insulin, HBA1c and glucose levels

Full Information

NCT ID

NCT00901043

First Posted

May 12, 2009

Last Updated

March 25, 2020

Sponsor

Griffin Hospital

Collaborators

California Walnut Commission

1. Study Identification

Unique Protocol Identification Number

NCT00901043

Brief Title

Effects of Walnut Consumption on Endothelial Function in Type 2 Diabetes

Acronym

WALNUT

Official Title

Effects of Walnut Consumption on Endothelial Function in Type 2 Diabetes: A Randomized, Controlled, Cross-over Trial

Study Type

Interventional

2. Study Status

Record Verification Date

March 2020

Overall Recruitment Status

Completed

Study Start Date

October 2007 (undefined)

Primary Completion Date

July 2008 (Actual)

Study Completion Date

September 2008 (Actual)

3. Sponsor/Collaborators

Responsible Party, by Official Title

Sponsor

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 sustained walnut consumption on endothelial function and lipid markers in patients with Type 2 diabetes mellitus.

Detailed Description

Evidence-based guidelines for the management of type 2 diabetes mellitus and related cardiovascular disease (CVD) refer to cardioprotective dietary fatty acid proportions. Several studies demonstrate the hypocholesteremic effects of walnuts in energy restricted diets. To our knowledge, the health benefits accrued as a result of addition of walnuts to an ad libitum diet in type 2 diabetic subjects have not been studied. Addition of walnuts to an ad libitum diet represents a practical way to achieve the recommended fatty acid proportions. The proposed study will examine whether a total dietary pattern inclusive of walnuts, will result in amelioration of cardiac risk as measured by improvement in endothelial function and glycemic control in type 2 diabetics. Results of the study will have important implications for clinicians and dietitians in dietary management of type 2 diabetes. Demonstrating that walnuts can be regarded as beneficial components of dietary management of type 2 diabetes is of relevance to the walnut industry as well. The study employs a pragmatic approach to approximate dietary practices in a real world setting thus enhancing the external validity of the study. If positive, the study results can inform future marketing efforts of the California Walnut Commission. Demonstrating that addition of walnuts to an ad libitum diet can potentially lead to improvement in endothelial function, improve lipid profiles, glycemic control and reduce the risk of CVD complications in diabetic patients has important applications for dietary management of diabetes.

6. Conditions and Keywords

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

DIABETES MELLITUS TYPE 2

7. Study Design

Primary Purpose

Treatment

Study Phase

Not Applicable

Interventional Study Model

Crossover Assignment

Masking

None (Open Label)

Allocation

Randomized

Enrollment

24 (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

Ad lib diet

Arm Type

Active 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)

Ad lib diet

Intervention Description

Eight weeks without walnut supplementation

Primary Outcome Measure Information:

Title

Brachial artery flow mediated dilation (FMD)

Time Frame

8 weeks

Secondary Outcome Measure Information:

Title

Change in weight, waist circumference, blood pressure, fasting lipids, fasting insulin, HBA1c and glucose levels

Time Frame

8 weeks

10. Eligibility

Sex

All

Minimum Age & Unit of Time

35 Years

Maximum Age & Unit of Time

75 Years

Accepts Healthy Volunteers

Eligibility Criteria

Inclusion Criteria: men and women ages 35-75 non-smoker able to have blood pressure taken bilaterally diagnosed with type 2 diabetes by physician for at least one year stable glucose levels and medication dose for the past 3 months not on insulin therapy Exclusion Criteria: failure to meet inclusion criteria anticipated inability to complete or comply with study protocol for any reason (e.g., inability to communicate in English, dementia) or any unstable medical condition that would limit the ability of a subject to participate fully in the trial (e.g., wasting illness, AIDS, tuberculosis, psychotic disorder) diagnosed eating disorder use of lipid-lowering or antihypertensive medications (statins, red rice yeast extract, garlic) unless stable on medication for at least 3 months and willing to refrain from taking medication for 12 hours prior to endothelial function (EF) scanning, vasoactive medication (i.e., glucocorticoids, antineoplastic agents, psychoactive agents, or bronchodilators) or nutriceuticals regular use of multivitamins and/or complementary or alternative supplement therapy and unwillingness to discontinue supplementation for at least 8 weeks prior to study initiation and for study duration any rheumatologic disease requiring regular use of nonsteroidal antiinflammatory drug (NSAIDs) or alternative medications regular use of fiber supplements preexisting cardiovascular disease, including symptomatic coronary artery disease (CAD), myocardial infarction, angina pectoris, anginal equivalent, peripheral vascular disease (claudication, amputation, or revascularization) congestive heart failure, carotid stenosis, aortic stenosis or stroke; diabetes, sleep apnea, severe uncontrolled hypertension (systolic blood pressure > 180 mmHg or diastolic blood pressure > 105 mmHg) coagulopathy, known bleeding diathesis or history of clinically significant hemorrhage; current use of warfarin clinically significant anemia (Hct < 36% in men, < 33% in women) intestinal or stomach disease inability to use right or left arm for endothelial function testing for any reason such as breast surgery, trauma, radiation to right axilla, lymphedema, right arm shunt, severe vascular disease in right arm subjects on a disease specific diet subjects on a weight control diet subjects on a vegan diet allergy to any kind of nut, including walnuts and peanuts

Overall Study Officials:

First Name & Middle Initial & Last Name & Degree

DAVID L KATZ, MD

Organizational Affiliation

Yale-Griffin Prevention Research Center

Official's Role

Principal Investigator

Facility Information:

Facility Name

Griffin Hospital

City

Derby

State/Province

Connecticut

ZIP/Postal Code

06418

Country

United States

12. IPD Sharing Statement

Learn more about this trial

Effects of Walnut Consumption on Endothelial Function in Type 2 Diabetes

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