Low Glycemic Index Diets vs. High Cereal Fibre Diets in Type 2 Diabetes
|Type 2 Diabetes Cardiovascular Disease||Other: Low Glycemic Index diet Other: High Cereal Fibre Diets|
|Study Design:||Allocation: Randomized
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|
- Change in Hemoglobin A1c [ Time Frame: 6 months ]
- Change in Fasting Glucose [ Time Frame: 6 months ]
- serum FFA [ Time Frame: 6 months ]
- C-peptide [ Time Frame: 6 months ]
- CRP [ Time Frame: 6 months ]
- IGF-I [ Time Frame: 6 months ]
- IGFBP-3 [ Time Frame: 6 months ]
- Serum apo AI [ Time Frame: 6 months ]
- apo B [ Time Frame: 6 months ]
- apo Lp(a) [ Time Frame: 6 months ]
- amino acids [ Time Frame: 6 months ]
- Plasma lipids and lipoproteins (TG, LDL, HDL) [ Time Frame: 6 months ]
- Oxidized LDL [ Time Frame: 6 months ]
- Change in Urinary creatinine [ Time Frame: 6 months ]
- urea [ Time Frame: 6 months ]
- Urinary C-peptide [ Time Frame: 6 months ]
|Study Start Date:||September 2004|
|Study Completion Date:||June 2007|
|Primary Completion Date:||June 2007 (Final data collection date for primary outcome measure)|
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
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.
Please refer to this study by its ClinicalTrials.gov identifier: NCT00438698
|St. Michael's Hospital|
|Toronto, Ontario, Canada, M5C 2T2|
|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|