Now Available: Final Rule for FDAAA 801 and NIH Policy on Clinical Trial Reporting

Low Glycemic Index Diets vs. High Cereal Fibre Diets in Type 2 Diabetes

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
David Jenkins, University of Toronto
ClinicalTrials.gov Identifier:
NCT00438698
First received: February 21, 2007
Last updated: December 15, 2015
Last verified: December 2015
  Purpose
Large observational studies have shown cereal fiber to protect from diabetes and heart disease. Despite the success of acarbose, an α-glucosidase hydrolase inhibitor, which lowers the glycemic index of foods containing starch, sucrose and maltodextrins, the use of diets containing low glycemic index foods still remains to be established. We will therefore provide otherwise healthy individuals with type 2 diabetes intensive counseling on food selection either to improve glucose control using high cereal fiber dietary strategies or low glycemic index foods. Studies will last 6 months with bloods taken for HbA1c, glucose and blood lipids. If the study shows a benefit for either or both diets then use of high fiber and/or low glycemic index foods in the diet may provide another potential way to improve glucose control and lower cholesterol levels in non-insulin dependent diabetes.

Condition Intervention
Type 2 Diabetes
Cardiovascular Disease
Other: Low Glycemic Index diet
Other: High Cereal Fibre Diets

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Single Blind (Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Effect of Low Glycemic Index Diets on Glucose Control in Non-Insulin Dependent Diabetics

Resource links provided by NLM:


Further study details as provided by University of Toronto:

Primary Outcome Measures:
  • Change in Hemoglobin A1c [ Time Frame: 6 months ] [ Designated as safety issue: Yes ]
  • Change in Fasting Glucose [ Time Frame: 6 months ] [ Designated as safety issue: Yes ]

Secondary Outcome Measures:
  • serum FFA [ Time Frame: 6 months ] [ Designated as safety issue: No ]
  • C-peptide [ Time Frame: 6 months ] [ Designated as safety issue: No ]
  • CRP [ Time Frame: 6 months ] [ Designated as safety issue: No ]
  • IGF-I [ Time Frame: 6 months ] [ Designated as safety issue: No ]
  • IGFBP-3 [ Time Frame: 6 months ] [ Designated as safety issue: No ]
  • Serum apo AI [ Time Frame: 6 months ] [ Designated as safety issue: No ]
  • apo B [ Time Frame: 6 months ] [ Designated as safety issue: No ]
  • apo Lp(a) [ Time Frame: 6 months ] [ Designated as safety issue: No ]
  • amino acids [ Time Frame: 6 months ] [ Designated as safety issue: No ]
  • Plasma lipids and lipoproteins (TG, LDL, HDL) [ Time Frame: 6 months ] [ Designated as safety issue: No ]
  • Oxidized LDL [ Time Frame: 6 months ] [ Designated as safety issue: No ]
  • Change in Urinary creatinine [ Time Frame: 6 months ] [ Designated as safety issue: No ]
  • urea [ Time Frame: 6 months ] [ Designated as safety issue: No ]
  • Urinary C-peptide [ Time Frame: 6 months ] [ Designated as safety issue: No ]

Enrollment: 210
Study Start Date: September 2004
Study Completion Date: June 2007
Primary Completion Date: June 2007 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Low Glycemic Index Diet
Diet with low glycemic index carbohydrates
Other: Low Glycemic Index diet
Diet to emphasize carbohydrate foods low in glycemic index
Active Comparator: High Fiber Diet
Diet with high cereal fibre choices
Other: High Cereal Fibre Diets
Diet to emphasize whole wheat carbohydrate cgoices

Detailed Description:

Recruitment: Subjects will be recruited by placing advertisements in local newspapers and by distributing similar advertisements to the diabetes clinic and diabetes education programs.

Information Sessions: Approximately 1000 volunteers in groups of 10-30 with or without spouses will attend one of a number of evening information sessions run from the Risk Factor Modification Center at St. Michael's Hospital. During the sessions the exact nature of the study will be described and volunteers will have the opportunity to ask specific questions about the study and taste the high fiber and low glycemic index foods.

Screening: Potential subjects will then fill in and return to the investigators a detailed questionnaire concerning their medical history, medications (including vitamin, mineral and nutritional supplements) smoking habits, alcohol intake and exercise pattern and whether they are currently on a specific diet. Details will also be obtained concerning planned vacations. Those subjects deemed potentially eligible will be asked to give a fasting blood sample at the Risk Factor Modification Center. Individuals who meet the study criteria, are invited to return again to the Center. The principles of the diabetic diet which they are already expected to be following will be reinforced, which incorporate the key elements of an NCEP Step 2 diet (total calories from fat <30%, saturated fat <7%, polyunsaturated fat <10%, dietary cholesterol <200 mg/day).

All subjects will then be randomized to one 24-week treatment in a two-treatment parallel design.

Treatments: 1) low glycemic index dietary advice (e.g. to eat intact grain cereals, pumpernickel bread, parboiled rice, cracked wheat, pasta, peas, beans and lentils) 2) high cereal fiber diet. Background diets will be the subjects' diabetic diets, modified as above, which will conform to CDA and NCEP Step 2 guidelines. Diet histories will be recorded at weeks 0, 2, 4, 8, 12, 16 and 24. These diets will be assessed for consistency by the dietitian in the subject's presence. Where necessary, modifications in diet will be made to ensure weight maintenance. Compliance will be assessed by 7 day food records.

Duration: the study will consist of four months recruitment and patient selection, during which time estimation of individual caloric requirements will be performed, and 6 months treatment period

Study Details: Fasting blood samples are obtained at day zero and weeks 2, 4, 8, 12, 16 and 24 of each study period. Twenty-four hour urine for urinary C-peptide analyses will be obtained immediately prior to the beginning of the study and at the end of each 24-week treatment phase.

Palatability and satiety: subjects will record their ratings using a 9-point bipolar semantic scale at weekly intervals during each study phase.

Anthropometric measures: height at recruitment, waist and hip circumference, and body composition will be taken immediately prior to and at the end of each study phase. Body weight and blood pressure will be measured at clinic visits.

This study will help to indicate whether dietary advice can make a significant difference to glycemic control as has been the case with drug therapy to reduce postprandial glycemia.

  Eligibility

Ages Eligible for Study:   21 Years to 100 Years   (Adult, Senior)
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Men and postmenopausal women with type 2 diabetes treated with diet plus oral hypoglycemic agents (Sulfonylureas, Biguanides, Thiazolidinediones , and new secretagogues (Repaglinide)) at a stable dose for at least 3 months prior to starting the study
  • HbA1c between 6.5 and 8.0% at recruitment
  • living within a 40 km radius of St. Michael's Hospital
  • Diabetes diagnosed > 6 months prior to randomization

Exclusion Criteria:

  • diabetic complications: clinically significant gastroparesis, retinopathy, nephropathy, neuropathy, hepatic disease, or CHD (current clinically significant CHD e.g. unstable angina)
  • taking insulin or acarbose
  • smoking or significant alcohol intake (> 1 drink/day)
  • serum triglycerides > 4.0 mmol/L
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00438698

Locations
Canada, Ontario
St. Michael's Hospital
Toronto, Ontario, Canada, M5C 2T2
Sponsors and Collaborators
University of Toronto
Investigators
Principal Investigator: David JA Jenkins, MD, PhD University of Toronto, St. Michael's Hospital
Study Director: Cyril WC Kendall, PhD University of Toronto, St. Michael's Hospital
  More Information

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: David Jenkins, Professor, University of Toronto
ClinicalTrials.gov Identifier: NCT00438698     History of Changes
Other Study ID Numbers: REB 04-021  CIHR RCT#: 67894 
Study First Received: February 21, 2007
Last Updated: December 15, 2015
Health Authority: Canada: Canadian Institutes of Health Research

Keywords provided by University of Toronto:
Nutrition
Type 2 Diabetes

Additional relevant MeSH terms:
Diabetes Mellitus, Type 2
Cardiovascular Diseases
Diabetes Mellitus
Glucose Metabolism Disorders
Metabolic Diseases
Endocrine System Diseases

ClinicalTrials.gov processed this record on September 30, 2016