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

Gestational Diabetes Mellitus Clinical Trial

— GIinGDM  

Official title:

The Effect of a Low GI Diet on Maternal and Neonatal Markers of Glycaemic Control and Postpartum Diabetes Risk SUBSTUDY The Effect of a Low GI Diet on Postpartum Markers of Oxidation in Breast Milk of Women With Gestational Hyperglycaemia

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01589757
• Other study ID #: UofTORE26937
• Status: Completed
• Phase: Phase 2/Phase 3
• First received: April 19, 2012
• Last updated: May 19, 2016
• Start date: October 2011
• Est. completion date: September 2015

Study information

• Verified date: May 2016
• Source: University of Toronto
• Contact: n/a
• Is FDA regulated: No
• Health authority: Canada: Health Canada
• Study type: Interventional

Clinical Trial 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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 99
• Est. completion date: September 2015
• Est. primary completion date: September 2015
• Accepts healthy volunteers: No
• Gender: Female
• Age group: 18 Years and older

Eligibility

MAIN STUDY

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

Study Design

Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Treatment

Related Conditions & MeSH terms

• Diabetes Mellitus
• Diabetes, Gestational
• Gestational Diabetes Mellitus

Intervention

Other:
• 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.
• 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.

Locations

Country	Name	City	State
Canada	MAIN STUDY ONLY: St Joseph's Heathcare Hamilton, 50 Charlton Avenue East	Hamilton	Ontario
Canada	Mt Sinai Hospital	Toronto	Ontario
Canada	St. Michael's Hospital	Toronto	Ontario
Canada	Sunnybrook Health Sciences Centre	Toronto	Ontario

Sponsors (4)

Lead Sponsor	Collaborator
University of Toronto	Canadian Diabetes Association, Canadian Foundation for Dietetic Research (CFDR), Canadian Institutes of Health Research (CIHR)

Country where clinical trial is conducted

Canada, 

References & Publications (7)

Ceriello A. Acute hyperglycaemia and oxidative stress generation. Diabet Med. 1997 Aug;14 Suppl 3:S45-9. Review. — View Citation

Ceriello A. The emerging role of post-prandial hyperglycaemic spikes in the pathogenesis of diabetic complications. Diabet Med. 1998 Mar;15(3):188-93. Review. — View Citation

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. — View Citation

Grant SM, Wolever TM. Perceived barriers to application of glycaemic index: valid concerns or lost in translation? Nutrients. 2011 Mar;3(3):330-40. doi: 10.3390/nu3030330. Epub 2011 Feb 28. Review. — View Citation

Huang D, Ou B, Prior RL. The chemistry behind antioxidant capacity assays. J Agric Food Chem. 2005 Mar 23;53(6):1841-56. Review. — View Citation

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

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

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	MAIN STUDY: Percentage of postprandial self monitored blood glucose (SMBG) values within the target range	SMBG values are obtained 4 times daily (1 fasting and 3 postprandial) throughout the study from the randomization to delivery. The endpoint is a single value for each participant - namely the percentage of all the postprandial SMBG values within the target range recommended by the Canadian Diabetes Association (5.0 to 6.6 mmol/L)	From randomization to delivery	No
Primary	SUB-STUDY (n=75): Oxygen Radical Absorbance Capacity (ORAC) (Antioxidant Capacity) of transitional and mature breast milk.	Breast milk samples (25 mL) will be collected 1 week and 8 weeks after birth from a complete breast milk collection. Measures will be compared between and within groups.	1 week and 8 weeks postpartum	No
Secondary	MAIN STUDY: Infant birth weight	Weight of the baby at delivery in grams.	At delivery	No
Secondary	MAIN STUDY: Percentage of self-monitored fasting glucose values within the target range	SMBG values are obtained 4 times daily (1 fasting and 3 postprandial) throughout the study from the start of the intervention to delivery. The endpoint is a single value for each participant - namely the percentage of all the fasting SMBG values within the target range recommended by the Canadian Diabetes Association (3.8 to 5.2 mmol/L)	From randomization to delivery	No
Secondary	MAIN STUDY: Glucose variability	SMBG values are obtained 4 times daily (1 fasting and 3 postprandial) throughout the study from the randomization to delivery. This endpoint is the coefficient of variation of all the SMBG values obtained (CV = 100*SD/mean), where SD is standard deviation; a single value for each participant.	From randomization to delivery	No
Secondary	MAIN STUDY: Insulin prescription incidence	Proportion of women prescribed insulin during the intervention	From randomization to delivery	No
Secondary	MAIN STUDY: Mean fasting glucose	SMBG values are obtained 4 times daily (1 fasting and 3 postprandial) throughout the study from the randomization to delivery. The endpoint is the mean of all fasting SMBG values obtained - a single value for each participant.	From randomization to delivery	No
Secondary	MAIN STUDY: Mean postprandial glucose	SMBG values are obtained 4 times daily (1 fasting and 3 postprandial) throughout the study from the randomization to delivery. This endpoint is the mean of all postprandial SMBG values obtained; a single value for each participant.	From randomization to delivery	No
Secondary	MAIN STUDY: Mean post-breakfast glucose	SMBG values are obtained 4 times daily (1 fasting and 3 postprandial) throughout the study from the randomization to delivery. This endpoint is the mean of all SMBG values 2 hours after breakfast; a single value in each participant.	From randomization to delivery	No
Secondary	MAIN STUDY: Mean post-lunch blood glucose	SMBG values are obtained 4 times daily (1 fasting and 3 postprandial) throughout the study from the randomization to delivery. This endpoint is the mean of all SMBG values 2 hours after lunch; a single value in each participant.	From randomization to delivery	No
Secondary	MAIN STUDY: Mean post-dinner blood glucose	SMBG values are obtained 4 times daily (1 fasting and 3 postprandial) throughout the study from the randomization to delivery. This endpoint is the mean of all SMBG values 2 hours after dinner; a single value in each participant.	From randomization to delivery	No
Secondary	MAIN STUDY: Change in LDL oxidation at 4 weeks	Difference between LDL oxidation measured in fasting venous blood at randomization and 4 weeks.	Change from randomization in LDL oxidation at 4 weeks.	No
Secondary	MAIN STUDY: LDL oxidation 6-8 weeks after delivery	LDL oxidation measured in fasting venous blood 6-8 weeks after delivery.	6-8 weeks after delivery	No
Secondary	MAIN STUDY: Change in Oxygen Radical Absorbance Capacity (ORAC) of plasma at 4 weeks	Difference in Oxygen Radical Absorbance Capacity (ORAC) of plasma measured in venous serum at randomization and 4 weeks.	Change from randomization to 4 weeks	No
Secondary	MAIN STUDY: Change in c-reactive protein (CRP) at 4 weeks	Difference in c-reactive protein concentration in venous serum from baseline at 4 weeks.	Change in CRP from randomization at 4 weeks	No
Secondary	MAIN STUDY: Post-partum CRP	Concentration of venous serum c-reactive protein 6-8 weeks after delivery.	6-8 weeks after delivery	No
Secondary	MAIN STUDY: Post-partum fasting serum glucose	Venous fasting serum glucose 6-8 weeks after delivery	6-8 weeks after delivery	No
Secondary	MAIN STUDY: Post-partum serum glucose concentration 2 hours after consumption of 75g oral glucose (2hrPC serum glucose).	Venous serum glucose concentration 2 hours after consumption of 75g oral glucose (oral glucose tolerance test).	6-8 weeks after delivery	No
Secondary	MAIN STUDY: Incidence of post-partum impaired glucose tolerance	Proportion of women with venous serum glucose concentration 2 hours after a 75g oral glucose tolerance test between 7.8 and 11.0 mmol/L, inclusive.	6-8 weeks after delivery	No
Secondary	MAIN STUDY: Incidence of post-partum diabetes mellitus	Proportion of women with diabetes 6-8 weeks after delivery. Diabetes is defined as fasting serum glucose greater than or equal to 7.0 mmol/L and/or serum glucose 2 hours after 75g oral glucose tolerance test greater than or equal to 11.1mmol/L.	6-8 weeks after delivery	No
Secondary	MAIN STUDY: Maternal weight gain	Difference between reported pre-pregnancy body weight and last body weight measured before delivery.	From pre-pregnancy to delivery: up to 9 months	No
Secondary	MAIN STUDY: Rate of maternal weight gain	Difference between maternal body weight at randomization and last body weight measured before delivery divided by the number of weeks between the measurements.	From randomization to delivery	No
Secondary	MAIN STUDY: Change in infant weight	Difference between infant birthweight and weight 6-8 weeks after delivery.	Change in infant body weight from birth to 6- 8 weeks	No
Secondary	MAIN STUDY & SUB-STUDY (n=75): Maternal dietary intake	Dietary analysis will be conducted using software containing the Canadian Nutrient File, supplemented with data that used standardized GI testing methodology. Comparison will be made between and within groups.	From randomization to 6- 8 weeks post-partum	No
Secondary	SUB-STUDY (n=75): Concentration of vitamin C, E, and Beta-carotene in transitional breast milk	Concentration of vitamin C, vitamin E and beta-carotene in breast milk collected 1 week after delivery. Comparison will be made between and within study groups.	1 week after delivery	No
Secondary	SUB-STUDY (n=75): Concentration of vitamin C, E, and Beta-carotene in mature breast milk	Concentration of vitamin C, vitamin E and beta-carotene in breast milk collected 6-8 weeks after delivery. Comparison will be made between and within study groups.	6-8 weeks after delivery	No
Secondary	MAIN STUDY: Infant demographics	Collection of infant demographics, such as gestational age at birth, sex, incidence and type of complications as noted in maternal or infant chart, mode of delivery, length of stay in hospital	Delivery to 6-8 weeks postpartum	No
Secondary	MAIN STUDY: Change in infant body measurements from birth to 6-8 weeks post-partum	Weight, head circumference, and height/length	Change in infant body measurements from delivery to 6-8 weeks post-partum	No
Secondary	MAIN STUDY: Infant APGAR score at delivery	Infant APGAR score at delivery as recorded in maternal medical chart.	Delivery	No
Secondary	MAIN STUDY: Change in maternal blood pressure and resting pulse from randomization to 4 weeks	Difference between maternal blood pressure and resting pulse from randomization at4 weeks.	Change from randomization to 4 weeks.	No
Secondary	MAIN STUDY: Maternal blood pressure and resting pulse at 6-8 weeks post-partum	Maternal blood pressure and resting pulse at 6-8 weeks post-partum.	6-8 weeks after delivery	No
Secondary	MAIN STUDY: Infant waist circumference at 6-8 weeks	Infant waist circumference at 6-8 weeks.	6-8 weeks after delivery	No
Secondary	MAIN STUDY: Change in ultrasound measurements from randomization to delivery.	Difference between infant ultrasound measurements (Bi-parietal diameter, head circumference, abdominal circumference, and femur length) from baseline to delivery.	Change from randomization to delivery	No
Secondary	MAIN STUDY: Maternal height at baseline	Maternal height at baseline	Baseline	No
Secondary	MAIN STUDY: Maternal medical history	Maternal medical history	Baseline	No
Secondary	MAIN STUDY: Maternal medical complications from baseline to 6-8 weeks post-partum	Incidence and type of maternal medical complications from baseline to 6-8 weeks post-partum	Baseline to 6-8 weeks after delivery	No
Secondary	MAIN STUDY: Change in maternal weight from delivery at 6-8 weeks post-partum	Difference in maternal weight from delivery at 6-8 weeks postpartum.	Difference between delivery and 6-8 weeks post-partum	No
Secondary	MAIN STUDY: Maternal pre-natal demographic information	Maternal pre-natal demographic information (e.g. ethnicity, language used at home, household food preparation and purchasing, education obtained, employment status, treatment of diabetes, prior exposure to a registered dietitian, cigarette, recreational drug, and alcohol use before and during pregnancy, and physical activity) using a pre-tested, face-validated questionnaire.	Baseline	No
Secondary	MAIN STUDY: Maternal post-partum socio-demographic data related to infant feeding practices	Socio-demographic factors previously identified in the literature as affecting infant feeding practices; including access to breastfeeding education while in hospital.	6-8 weeks after delivery	No
Secondary	MAIN STUDY: Length of time between delivery and maternal breast fullness	Length of time between delivery and maternal breast fullness.	Time after delivery	No
Secondary	MAIN STUDY: Change in conjugated dienes at 4 weeks	Difference between conjugated dienes of plasma measured in venous serum at baseline and 4 weeks.	change from baseline to 4 weeks.	No
Secondary	MAIN STUDY: Conjugated dienes post-partum	Conjugated dienes in fasting venous blood 6-8 weeks after delivery	6-8 weeks after delivery	No
Secondary	MAIN STUDY: Oxygen Radical Absorbance Capacity (ORAC) of venous plasma post-partum	ORAC measured in fasting venous blood 6-8 weeks after delivery	6-8 weeks after delivery	No
Secondary	MAIN STUDY: Change in full lipid profile at 4 weeks	Difference in full lipid profile of fasting venous blood at baseline and 4 weeks.	Change in full lipid profile of plasma from baseline at 4 weeks	No
Secondary	MAIN STUDY: Full lipid profile post-partum	Full lipid profile of fasting venous blood at 6-8 weeks post-partum	6-8 weeks after delivery	No
Secondary	MAIN STUDY: Change in incidence and severity of symptoms from baseline to 6-8 weeks postpartum	Difference in the incidence and severity of maternal symptoms present from baseline to 6-8 weeks postpartum using a standardised questionnaire.	Change from baseline to 6-8 weeks postpartum	No
Secondary	MAIN STUDY: Infant feeding practices	Maternal infant feeding practices from delivery to 6-8 weeks postpartum	6-8 weeks after delivery	No
Secondary	MAIN STUDY: Participant satisfaction of baseline education class	Participant reactions and opinions on baseline education class using a face-validated, pre-tested questionnaire.	Baseline	No
Secondary	MAIN STUDY: Change in participant knowledge of GI from baseline to 6-8 weeks after delivery	Difference in participant knowledge of GI from randomization pre-education class) to 6-8 weeks after delivery using a face-validated, pre-tested questionnaire.	Change in GI knowledge from randomization to 6-8 weeks after delivery	No
Secondary	MAIN STUDY: Participant knowledge of GI at baseline	Participant knowledge of GI at baseline (pre-education class)using a validated questionnaire.	Baseline	No
Secondary	MAIN STUDY: Change in participant opinion on availability and acceptability of study diet foods	Difference in participant opinion on availability and acceptability of study diet foods from 2 weeks to 6-8 weeks after delivery using a validated questionnaire.	Change in opinion from 2 weeks to 6-8 weeks after delivery	No
Secondary	MAIN STUDY: Difference in dietary GI between study groups.	Difference in dietary GI between study groups from baseline to 6-8 weeks post delivery using a short-form semi-quantitative food frequency questionnaire (FFQ). The FFQ collects dietary intake data on the 3 months preceding administration. The FFQ has been standardised and evaluated for readability by nutrition professionals, clinicians and/or researchers with experience in surveying, and has been face-validated and pre-tested.	From baseline to 6-8 weeks after delivery	No
Secondary	MAIN STUDY: Change in behaviour from baseline (pre-class) to 6-8 weeks after delivery.	Difference in behaviour within and between groups from baseline (pre-class) to 6-8 weeks after delivery using face-validated, pre-tested questionnaires, including a short-form semi-quantitative food frequency questionnaire (FFQ). The FFQ collects dietary intake data on the 3 months preceding administration. The FFQ has been standardised and evaluated for readability by nutrition professionals, clinicians and/or researchers with experience in surveying.	Change in behaviour from baseline (pre-class) to 6-8 weeks after delivery	No