Low-Intermediate-Glycemic Index Caribbean Foods Versus High Glycemic Index Foods in Type 2 Diabetes
Condition: Type 2 Diabetes; Inflammation; Cardiovascular Disease
MeSH terms: Cardiovascular Diseases; Diabetes Mellitus; Diabetes Mellitus, Type 2; Inflammation
Study type: Interventional

Summary: 
      The purpose of this study is to determine whether low and intermediate GI Caribbean foods are
      effective in the management of type 2 diabetes.
    

Detailed description: 
      Recruitment: Subjects for the study were sourced primarily from the University Hospital of
      the West Indices (Diabetic Clinic) and from the Diabetes Association of Jamaica Outreach
      Centers in Kingston and St. Catherine. Volunteers were also recruited through clinical visits
      and by opportunistic population screenings and by placing advertisements in local newspapers
      and by distributing similar advertisements to the diabetes clinic and diabetes education
      programs.

      Information Sessions: Approximately 112 volunteers in groups of 10-30 with or without spouses
      will attend one of a number of evening information sessions at run from the Department of
      Basic Medical Sciences (Biochemistry Section), University of the West Indies. 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.

      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 Biotechnology Center, University of the West Indies. Individuals who meet the study
      criteria, are invited to return again to the Department. The principles of the diabetic diet
      which they are already expected to be following will be reinforced by the study nutritionist
      whereby consuming a diet with more than 50% of daily calories from carbohydrate; less than
      10% from saturated fat and 20% from mono- and polyunsaturated fat, or up to 25% if the
      surplus is from monounsaturated fat; cholesterol less than 300 mg/day; and approximately 1.0
      g protein per kg ideal weight per day. An increase in the intake of dietary fiber to 15 g per
      1000 kcal was encouraged. All subjects were then 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, boiled
      green banana, boiled sweet potato, boiled round leaf yellow yams and boiled breadfruit) 2)
      high cereal fiber diet. Background diets will be the subjects' diabetic diets, modified as
      above, which will conform. Diet histories will be recorded at weekly for 24 weeks. These
      diets will be assessed for consistency by the dietitian in the subject's presence through
      dietary recall and semi-quantitative assessment of food portion sizes consumed. 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 were 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 a low-intermediate-GI indigenous Caribbean foods
      dietary advice can reduce the postprandial glycemia, inflammation and cardiovascular risks in
      person with type 2 diabetes.
    

Intervention name(s): Low-Intermediate-Glycemic Index diets; High GI diet
Intervention type(s): Dietary Supplement; Dietary Supplement
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Investigator)
Primary purpose: Treatment