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OverweightNCT00608049

Effect of Amount and Type of Dietary Carbohydrates on Risk for Cardiovascular Heart Disease and Diabetes

A study testing High carbohydrate and low glycemic index (GI) diet, Low carbohydrate and low GI diet and High carbohydrate and high GI diet in people with Overweight and Cardiovascular Diseases, run by Brigham and Women's Hospital at 2 sites in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Cardiovascular disease (CVD) and diabetes are health conditions that are strongly influenced by a person's diet. Although the best diet to prevent CVD and diabetes is uncertain, reducing intake of saturated and transunsaturated fats is known to help lower cardiovascular risk. Read more about this study

Who is it for?
Ages 30 years and olderHealthy volunteers can take part
Conditions the study is for
Overweight, Cardiovascular Diseases
What is being tested?
High carbohydrate and low glycemic index (GI) diet, Low carbohydrate and low GI diet and High carbohydrate and high GI diet
Could I receive a placebo?
No, everyone receives an active treatment
How many people
189 participants
Where
2 sitesUnited States
Study dates
Feb 2008to Feb 2011
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 30 years and older
  • All sexes
  • Healthy volunteers accepted
  • Adult, Older adult

Who may be able to join

  • SBP of 120 to 159 mmHg and DBP less than 100 mmHg at study entry (mean over three screening visits) (note: participants with stage 2 hypertension [SBP greater than 160 mmHg or DBP greater than 100 mmHg] based on the mean over three screening visits will be excluded, as will participants with a mean SBP greater than 170 mmHg or DBP greater than 105 mmHg at any one visit)
  • Overweight or obese, as defined by a body mass index (BMI) greater than 25 kg/m2
  • Willing to eat at least one on-site meal per day, 5 days per week, and willing to eat study diets and nothing else during controlled feeding periods
  • Medication Exclusion Criteria:
  • Symptomatic ischemic heart disease (e.g., angina pectoris)
  • Regular use of medications that raise or lower BP during the 2 months prior to study entry
Show all 21Show fewer
  • Use of a lipid lowering agent in the 3 weeks prior to study entry
  • Unstable dose of hormone replacement therapy, thyroid hormone replacement therapy, and psychotropic medications known to cause weight gain or affect the outcome variables (unstable is defined as a change in dose within 2 months of study entry)
  • Use of insulin, oral hypoglycemic agent, lithium, oral corticosteroid, anti-psychotic drugs, weight loss medications, nitrate, or digitalis
  • Medical History Exclusion Criteria:
  • Active or prior CVD (e.g., stroke, heart attack, percutaneous transluminal coronary angioplasty, coronary artery bypass graft, congestive heart failure, symptomatic ischemic heart disease [angina], or arteriosclerotic cardiovascular disease-related therapeutic procedure)
  • Diabetes mellitus
  • Cancer diagnosis or treatment in the 2 years prior to study entry (note: people with non-melanoma skin cancer, localized breast cancer, or localized prostate cancer can enroll if they did not require systemic chemotherapy)
  • Active inflammatory bowel disease, malabsorption, or major gastrointestinal resection
  • Renal insufficiency as determined by a serum creatinine greater than 1.2 mg/dL for women or greater than 1.4 mg/dL for men (these participants can enroll if their estimated glomerular filtration rate is greater than 40 mL/min by either the Cockcroft-Gault equation or the simplified Modification of Diet in Renal Disease equation)
  • Emergency room visit or hospital stay for asthma or chronic obstructive pulmonary disease in the 6 months prior to study entry
  • Any serious illness not otherwise specified that would interfere with participation
  • Laboratory Exclusion Criteria:
  • Fasting LDL cholesterol greater than 220 mg/dL and triglycerides greater than 750 mg/dL
  • Fasting blood glucose greater than 125 mg/dL
  • Serum transaminase greater than 2 times the upper range of normal, or a clinical diagnosis of hepatitis

Who cannot join

None listed.

Trial locations and contacts

2 sites in 1 country.

United States2 sites
  • Johns Hopkins Medical Institutions

    Baltimore, Maryland, 21205

  • Harvard T. H. Chan School of Public Health

    Boston, Massachusetts, 02215

Other trials in United States

About this study

Official title: Optimal Macronutrient Intake - Carbohydrate

Cardiovascular disease (CVD) and diabetes are health conditions that are strongly influenced by a person's diet. Although the best diet to prevent CVD and diabetes is uncertain, reducing intake of saturated and transunsaturated fats is known to help lower cardiovascular risk. However, even diets low in these fats can vary widely in other energy providing nutrients, particularly carbohydrates. This study will determine the effects of a higher versus lower carbohydrate diet, each with a high or low glycemic index (GI) composition, on risk factors for CVD and diabetes.

Read the detailed description

A healthy diet can have a remarkable effect on a person's overall health. Research has consistently confirmed the association between diet and serious health problems, including heart disease, diabetes, high blood pressure, and gastrointestinal disorders. Most healthy diets aimed at disease prevention promote a low intake of fats, but the optimal diet to prevent CVD and related disorders is uncertain. Recent emphasis has turned to the influence of carbohydrate consumption on risk of CVD and diabetes. Carbohydrates comprise a wide range of foods, which are categorized by their absorption rate, also known as glycemic index (GI). There is much current debate over how the level and type of dietary carbohydrates affect cardiovascular health. This study will determine the effects of a higher versus lower carbohydrate diet, each with a high or low GI composition, on risk factors for CVD and diabetes.

Potential participants will attend three screening visits that will include questionnaires, clinical measurements, and blood and urine tests. Participants will then undergo an 8-day run-in phase to become familiar with the feeding patterns of four different diets: high carbohydrate with high GI, high carbohydrate with low GI, low carbohydrate with high GI, or low carbohydrate with low GI. During the run-in, participants will be provided all of their food, snacks, and calorie-containing beverages. Participants will also complete a daily food diary, symptoms questionnaire, medical and social history, and daily weigh-in. After meeting with a dietician to review progress, eligible participants will be randomly assigned to one of eight sequences of the four diet plans.

Participants will follow each of the four diet plans for 5 weeks, with a period of at least 2 weeks separating each plan. During each dieting period, participants will be provided all of their food and snacks and most beverages. All participants will be required to eat at least one on-site meal per day, 5 days per week. Participants will keep a daily food diary and will undergo weekly blood pressure measurements for the first 3 weeks of each dieting period. Assessments will occur in the fifth week of each of the four dieting periods and will include symptoms and satiety questionnaires, blood pressure measurements, and a blood draw. One month following the completion of the last dieting period, participants will receive nutritional counseling on the prevention of CVD.

Being tested
High carbohydrate and low glycemic index (GI) diet, Low carbohydrate and low GI diet, High carbohydrate and high GI diet, Low carbohydrate and high GI diet
Keywords
Blood Pressure, Diabetes, Nutrition, Dietary Carbohydrate, Lipoproteins, Insulin Resistance
Medical subject headings
Overweight, Cardiovascular Diseases, Diabetes Mellitus, Insulin Resistance

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • High carbohydrate and low glycemic index (GI) dietBehavioural

    The high carbohydrate and low GI diet will require 58% of daily calories to be from carbohydrates and will be composed of meals with a GI of less than 45 on the glucose scale.

  • Low carbohydrate and low GI dietBehavioural

    The low carbohydrate and low GI diet will require 40% of daily calories to be from carbohydrates and will be composed of meals with a GI of less than 45 on the glucose scale.

  • High carbohydrate and high GI dietBehavioural

    The high carbohydrate and high GI diet will require 58% of daily calories to be from carbohydrates and will be composed of meals with a GI of greater than 65 on the glucose scale.

  • Low carbohydrate and high GI dietBehavioural

    The low carbohydrate and high GI diet will require 40% of daily calories to be from carbohydrates and will be composed of meals with a GI of greater than 65 on the glucose scale.

Study groups in NCT00608049
Study groupRoleWhat they receive
1ExperimentalParticipants will follow four diet plans, each for a period of 5 weeks, in the following order: high carbohydrate/high GI, high carbohydrate/low GI, low carbohydrate/high GI, and low carbohydrate/low GI
Receives: Behavioral: High carbohydrate and low glycemic index (GI) diet; Behavioral: Low carbohydrate and low GI diet; Behavioral: High carbohydrate and high GI diet; Behavioral: Low carbohydrate and high GI diet
2ExperimentalParticipants will follow four diet plans, each for a period of 5 weeks, in the following order: high carbohydrate/high GI, high carbohydrate/low GI, low carbohydrate/low GI, and low carbohydrate/high GI
Receives: Behavioral: High carbohydrate and low glycemic index (GI) diet; Behavioral: Low carbohydrate and low GI diet; Behavioral: High carbohydrate and high GI diet; Behavioral: Low carbohydrate and high GI diet
3ExperimentalParticipants will follow four diet plans, each for a period of 5 weeks, in the following order: high carbohydrate/low GI, high carbohydrate/high GI, low carbohydrate/high GI, and low carbohydrate/low GI
Receives: Behavioral: High carbohydrate and low glycemic index (GI) diet; Behavioral: Low carbohydrate and low GI diet; Behavioral: High carbohydrate and high GI diet; Behavioral: Low carbohydrate and high GI diet
4ExperimentalParticipants will follow four diet plans, each for a period of 5 weeks, in the following order: high carbohydrate/low GI, high carbohydrate/high GI, low carbohydrate/low GI, and low carbohydrate/high GI
Receives: Behavioral: High carbohydrate and low glycemic index (GI) diet; Behavioral: Low carbohydrate and low GI diet; Behavioral: High carbohydrate and high GI diet; Behavioral: Low carbohydrate and high GI diet
5ExperimentalParticipants will follow four diet plans, each for a period of 5 weeks, in the following order: low carbohydrate/high GI, low carbohydrate/low GI, high carbohydrate/high GI, and high carbohydrate/low GI
Receives: Behavioral: High carbohydrate and low glycemic index (GI) diet; Behavioral: Low carbohydrate and low GI diet; Behavioral: High carbohydrate and high GI diet; Behavioral: Low carbohydrate and high GI diet
6ExperimentalParticipants will follow four diet plans, each for a period of 5 weeks, in the following order: low carbohydrate/high GI, low carbohydrate/low GI, high carbohydrate/low GI, and high carbohydrate/high GI
Receives: Behavioral: High carbohydrate and low glycemic index (GI) diet; Behavioral: Low carbohydrate and low GI diet; Behavioral: High carbohydrate and high GI diet; Behavioral: Low carbohydrate and high GI diet
7ExperimentalParticipants will follow four diet plans, each for a period of 5 weeks, in the following order: low carbohydrate/low GI, low carbohydrate/high GI, high carbohydrate/high GI, and high carbohydrate/low GI
Receives: Behavioral: High carbohydrate and low glycemic index (GI) diet; Behavioral: Low carbohydrate and low GI diet; Behavioral: High carbohydrate and high GI diet; Behavioral: Low carbohydrate and high GI diet
8ExperimentalParticipants will follow four diet plans, each for a period of 5 weeks, in the following order: low carbohydrate/low GI, low carbohydrate/high GI, high carbohydrate/low GI, and high carbohydrate/high GI
Receives: Behavioral: High carbohydrate and low glycemic index (GI) diet; Behavioral: Low carbohydrate and low GI diet; Behavioral: High carbohydrate and high GI diet; Behavioral: Low carbohydrate and high GI diet

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Systolic blood pressure (SBP), Low Density Lipoproteins (LDL) cholesterol, High Density Lipoproteins (HDL) cholesterol, triglycerides, and insulin sensitivity

    Measured: Measured at Week 5 of each dieting period

Secondary outcomes (3)
  1. Diastolic blood pressure (DBP); apolipoproteins B, CIII, A-I, and Very Low Density Lipoproteins (VLDL); and LDL with apolipoprotein CIII

    Measured: Measured at Week 5 of each dieting period

  2. Beta cell response, glucose effectiveness, and fructosamine; postprandial glucose, insulin, lipids, and hormone levels

    Measured: Measured at Week 5 of each dieting period

  3. Overall CVD risk using risk equations

    Measured: Measured at Week 5 of each dieting period

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted6 Feb 2008 (estimated)
  2. Study startFeb 2008
  3. Primary completionFeb 2011
  4. Study completionFeb 2011

Resources

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
Triple blind
Who is masked
Participant, Investigator, Outcomes assessor
Enrolment
189 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT00608049
Sponsor's protocol ID
481
Other IDs
R01HL084568
Status last verified
Jul 2016
First submitted
23 Jan 2008
Last updated
6 Jul 2016
Results posted
No
Data monitoring committee
Yes

Publications

  • Wu Y, Juraschek SP, Hu JR, Mueller NT, Appel LJ, Anderson CAM, Miller ER. Higher Carbohydrate Amount and Lower Glycemic Index Increase Hunger, Diet Satisfaction, and Heartburn in Overweight and Obese Adults in the OmniCarb Randomized Clinical Trial. J Nutr. 2021 Aug 7;151(8):2477-2485. doi: 10.1093/jn/nxab128.

    PubMed 34049396
  • Hu JR, Wu Y, Sacks FM, Appel LJ, Miller Iii ER, Young JH, Juraschek SP. Effects of carbohydrate quality and amount on plasma lactate: results from the OmniCarb trial. BMJ Open Diabetes Res Care. 2020 Aug;8(1):e001457. doi: 10.1136/bmjdrc-2020-001457.

    PubMed 32868311
  • Juraschek SP, Miller ER 3rd, Selvin E, Carey VJ, Appel LJ, Christenson RH, Sacks FM. Effect of type and amount of dietary carbohydrate on biomarkers of glucose homeostasis and C reactive protein in overweight or obese adults: results from the OmniCarb trial. BMJ Open Diabetes Res Care. 2016 Nov 14;4(1):e000276. doi: 10.1136/bmjdrc-2016-000276. eCollection 2016.

    PubMed 27933186
  • Juraschek SP, Chang AR, Appel LJ, Anderson CA, Crews DC, Thomas L, Charleston J, Miller ER 3rd. Effect of glycemic index and carbohydrate intake on kidney function in healthy adults. BMC Nephrol. 2016 Jul 8;17(1):70. doi: 10.1186/s12882-016-0288-5.

    PubMed 27391484
  • Juraschek SP, McAdams-Demarco M, Gelber AC, Sacks FM, Appel LJ, White KJ, Miller ER 3rd. Effects of Lowering Glycemic Index of Dietary Carbohydrate on Plasma Uric Acid Levels: The OmniCarb Randomized Clinical Trial. Arthritis Rheumatol. 2016 May;68(5):1281-9. doi: 10.1002/art.39527.

    PubMed 26636424
  • Sacks FM, Carey VJ, Anderson CA, Miller ER 3rd, Copeland T, Charleston J, Harshfield BJ, Laranjo N, McCarron P, Swain J, White K, Yee K, Appel LJ. Effects of high vs low glycemic index of dietary carbohydrate on cardiovascular disease risk factors and insulin sensitivity: the OmniCarb randomized clinical trial. JAMA. 2014 Dec 17;312(23):2531-41. doi: 10.1001/jama.2014.16658.

    PubMed 25514303

Questions about this trial

What is this clinical trial studying?

A study testing High carbohydrate and low glycemic index (GI) diet, Low carbohydrate and low GI diet and High carbohydrate and high GI diet in people with Overweight and Cardiovascular Diseases, run by Brigham and Women's Hospital at 2 sites 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 21 inclusion and 0 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 6 Jul 2016. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 2 sites 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?

Systolic blood pressure (SBP), Low Density Lipoproteins (LDL) cholesterol, High Density Lipoproteins (HDL) cholesterol, triglycerides, and insulin sensitivity (time frame: Measured at Week 5 of each dieting period). 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 NCT00608049, which also lists 6 linked publications.

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 6 Jul 2016.

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