MAIN STUDY: Low Glycaemic Index (GI) Diet in the Management of GDM SUB-STUDY: The Breast Milk Sub-Study

NCT ID: NCT01589757

Last Updated: 2016-05-20

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: PHASE2/PHASE3
• Total Enrollment: 99 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2011-10-31
• Study Completion Date: 2015-09-30

Brief Summary

MAIN STUDY: Low glycaemic index (GI) diets are recommended by the Canadian Diabetes Association for treating type 1 and 2 diabetes mellitus (DM), but the role of GI in the management of gestational diabetes(GDM)is not yet clear. The main purpose of this study is to determine the effect of a low GI diet on blood sugar control in women with GDM. The effect of a low GI diet on maternal oxidative stress, pregnancy and delivery outcomes and markers of risk for diabetes after birth in both the mother and baby will also be assessed. SUB-STUDY: The main purpose of the sub-study is to determine if the breast milk (BM) of women with GDM consuming a low GI diet will have a higher antioxidant capacity than the BM of women receiving a medium-high GI diet (control/standard care). The effect of a low glycaemic index diet on maternal dietary intake of specific nutrient-antioxidants (i.e. vitamin C, E, and beta-carotene) (prenatal and postpartum) and concentration of vitamin C, E, and beta-carotene in participants' transitional and mature BM will also be assessed. The ORAC (Oxygen radical absorbance capacity) assay will be used to assess overall antioxidant capacity. The antioxidant capacity of BM in women with GDM will also be compared with that of women without GDM.

Hypotheses:

MAIN: The use of low-GI foods in the management of GDM reduces postprandial BG and oxidative stress; thereby reducing maternal and infant perinatal complications.

SUB-STUDY: Breast milk (BM) of women with GDM consuming a low GI diet will have higher BM antioxidant than women receiving the medium to high GI diet. BM of women with GDM will have lower antioxidant capacity than that of women without GDM.

Detailed Description

MAIN STUDY: Use of low GI education is currently accepted by the Canadian Diabetes Association in treatment of type 1 and 2 DM, but is not included in the clinical practice guidelines(CPG) for management of GDM. Data collected to date support use of low GI in treatment of GDM, but more data are needed to influence CPG. In this study the effect of a low GI diet on maternal and neonatal markers of glycaemic control and postpartum diabetes risk in mother and baby will be determined. This study will also assess the role that maternal oxidative stress may play in this relationship.

Hypothesis: The use of low-GI foods in the management of GDM reduces postprandial BG and oxidative stress; thereby reducing maternal and infant perinatal complications.

SUB-STUDY: Breast milk (BM) is accepted as the optimal source of nutrition for infants. A wealth of literature on BM composition exists. This work includes measurement of antioxidants in BM. Women diagnosed with gestational hyperglycaemia have decreased antioxidant capacity in comparison to normoglycaemic pregnant women. A direct relationship exists between postprandial glycaemic response and oxidative stress. Low GI carbohydrate is converted to blood glucose (BG) more slowly than medium to high GI carbohydrate

Hypotheses: Breast milk (BM) of women with GDM consuming a low GI diet will have higher BM antioxidant than women receiving the medium to high GI diet. BM of women with GDM will have lower anti-oxidant capacity than that of women without GDM.

Conditions

Gestational Diabetes Mellitus

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: NONE

Study Groups

Standard Care

Standard care dietary advice to emphasize high fiber foods with a moderate to high GI

Group Type: PLACEBO_COMPARATOR

Low GI diet

Intervention Type: OTHER

Nutrition education according to standard care similar to the control group with supplementary GI-education. GI-education will be taught using the "Stop-Light-Method". This groups will be provided with food substitution lists (key-foods method) composed of low-GI carbohydrate-containing food. The GI-education tool(s) will build on standard care education where patients are taught which food groups contain carbohydrate.

Low GI Diet

Low GI dietary advice in addition to standard care

Group Type: EXPERIMENTAL

Standard Care

Intervention Type: OTHER

Standard dietary advice for women with GDM with special emphasis on use of high fiber or whole grain carbohydrate foods with a medium to high GI. What's on Your Plate? and 3-dimensional food models will be used to teach servings size and meal planning. This groups will be provided with food substitution lists (key-foods method) composed of medium to high GI foods.

Interventions

Standard Care

Standard dietary advice for women with GDM with special emphasis on use of high fiber or whole grain carbohydrate foods with a medium to high GI. What's on Your Plate? and 3-dimensional food models will be used to teach servings size and meal planning. This groups will be provided with food substitution lists (key-foods method) composed of medium to high GI foods.

Intervention Type: OTHER

Low GI diet

Nutrition education according to standard care similar to the control group with supplementary GI-education. GI-education will be taught using the "Stop-Light-Method". This groups will be provided with food substitution lists (key-foods method) composed of low-GI carbohydrate-containing food. The GI-education tool(s) will build on standard care education where patients are taught which food groups contain carbohydrate.

Intervention Type: OTHER

Other Intervention Names

medium to high Glycaemic Index; glycemic index; glycaemic index; low glycemic carbohydrates; low glycaemic carbohydrates

Eligibility Criteria

Inclusion Criteria

Women:

1. ≥ 18 years of age

2. diagnosed with gestational diabetes mellitus (GDM) or impaired glucose tolerance of pregnancy (IGTP) according to Canadian Diabetes Association (CDA) criteria

3. being followed within DIP (one of 4 sites)

4. willing and able to give informed consent

5. willing and able to comply with the study protocol

Exclusion Criteria

Women:

1. with acute or chronic illness other than GDM or IGTP or use of drug (other than insulin) which may affect carbohydrate metabolism, gastrointestinal function or carbohydrate digestion (i.e. crohn's disease, HIV/AIDS, liver disease, kidney disease etc.).

2. known to have type 1 or type 2 DM prior to pregnancy

3. known multi-fetal pregnancy at enrolment

4. ≥ 33 weeks' gestation

5. prescribed oral anti-hyperglycaemic medication

6. insurmountable language barriers

SUB-STUDY control group (women without GDM) Same as for Main study except absence of GDM

• Minimum Eligible Age: 18 Years
• Eligible Sex: FEMALE
• Accepts Healthy Volunteers: No

Sponsors

Canadian Diabetes Association

OTHER

Sponsor Role: collaborator

Canadian Institutes of Health Research (CIHR)

OTHER_GOV

Sponsor Role: collaborator

Canadian Foundation for Dietetic Research (CFDR)

OTHER

Sponsor Role: collaborator

University of Toronto

OTHER

Sponsor Role: lead

Responsible Party

Thomas Wolever

Professor

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Thomas MS Wolever, MD, PhD

Role: PRINCIPAL_INVESTIGATOR

University of Toronto/ St Michael's Hospital

Locations

MAIN STUDY ONLY: St Joseph's Heathcare Hamilton, 50 Charlton Avenue East

Hamilton, Ontario, Canada

St. Michael's Hospital

Toronto, Ontario, Canada

Mt Sinai Hospital

Toronto, Ontario, Canada

Sunnybrook Health Sciences Centre

Toronto, Ontario, Canada

Countries

Canada

References

Ceriello A. Acute hyperglycaemia and oxidative stress generation. Diabet Med. 1997 Aug;14 Suppl 3:S45-9. doi: 10.1002/(sici)1096-9136(199708)14:3+3.3.co;2-i.

Reference Type: BACKGROUND

PMID: 9272613 (View on PubMed)

Ceriello A. The emerging role of post-prandial hyperglycaemic spikes in the pathogenesis of diabetic complications. Diabet Med. 1998 Mar;15(3):188-93. doi: 10.1002/(SICI)1096-9136(199803)15:33.0.CO;2-V. No abstract available.

Reference Type: BACKGROUND

PMID: 9545118 (View on PubMed)

Huang D, Ou B, Prior RL. The chemistry behind antioxidant capacity assays. J Agric Food Chem. 2005 Mar 23;53(6):1841-56. doi: 10.1021/jf030723c.

Reference Type: BACKGROUND

PMID: 15769103 (View on PubMed)

Saenz AT, Elisia I, Innis SM, Friel JK, and Kitts DD. Use of ORAC to assess antioxidant capacity of human milk. Journal of Food Composition and Analysis 22:694-698, 2009

Reference Type: BACKGROUND

Elisia I, Kitts DD. Quantification of hexanal as an index of lipid oxidation in human milk and association with antioxidant components. J Clin Biochem Nutr. 2011 Nov;49(3):147-52. doi: 10.3164/jcbn.10-142. Epub 2011 Sep 3.

Reference Type: BACKGROUND

PMID: 22128211 (View on PubMed)

Wolever, TMS. The Glycaemic Index: A Physiological Classification of Dietary Carbohydrate. Ontario, Canada: CABI, 2006.

Reference Type: BACKGROUND

Grant SM, Wolever TMS. Perceived barriers to application of glycaemic index: valid concerns or lost in translation? Nutrients. 2011 Mar;3(3):330-340. doi: 10.3390/nu3030330. Epub 2011 Feb 28.

Reference Type: BACKGROUND

PMID: 22254100 (View on PubMed)

Other Identifiers

UofTORE26937

Identifier Type: -

Identifier Source: org_study_id