Gestational Diabetes MellitusPhase 2/3GIinGDMNCT01589757
MAIN STUDY: Low Glycaemic Index (GI) Diet in the Management of GDM SUB-STUDY: The Breast Milk Sub-Study
A Phase 2/3 study testing Low GI diet in people with Gestational Diabetes Mellitus, run by University of Toronto at 4 sites in Canada.
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. Read more about this study
- Who is it for?
- Ages 18 years and older, women only
- Conditions the study is for
- Gestational Diabetes Mellitus
- What is being tested?
- Low GI diet
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 99 participants
- Where
- 4 sitesCanada
- Study dates
- Oct 2011to Sep 2015
- Phase
- Phase 2/3
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- Women only
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Women:
- ≥ 18 years of age
- diagnosed with gestational diabetes mellitus (GDM) or impaired glucose tolerance of pregnancy (IGTP) according to Canadian Diabetes Association (CDA) criteria
- being followed within DIP (one of 4 sites)
- willing and able to give informed consent
- willing and able to comply with the study protocol
Who cannot join
- Women:
- 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.).
- known to have type 1 or type 2 DM prior to pregnancy
- known multi-fetal pregnancy at enrolment
- ≥ 33 weeks' gestation
- prescribed oral anti-hyperglycaemic medication
- insurmountable language barriers
- SUB-STUDY control group (women without GDM) Same as for Main study except absence of GDM
Trial locations and contacts
4 sites in 1 country.
Canada4 sites
MAIN STUDY ONLY: St Joseph's Heathcare Hamilton, 50 Charlton Avenue East
Hamilton, Ontario, L8N 4A6
St. Michael's Hospital
Toronto, Ontario, M5B 1W8
Mt Sinai Hospital
Toronto, Ontario, M5G 1X5
Sunnybrook Health Sciences Centre
Toronto, Ontario, Room H145, 2075 Bayview Avenue
About this study
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
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:
Read more
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.
Read the 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
- Being tested
- Standard Care, Low GI diet
- Keywords
- "glycaemic index", "glycemic index", hyperglycaemia, hyperglycemia, pregnancy, "dietary intervention", "education evaluation", antioxidant, "Impaired Glucose Tolerance of Pregnancy", "Gestational Diabetes Mellitus", "Breast Milk"
- Medical subject headings
- Diabetes, Gestational, Hyperglycemia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Standard CareOther
Also called medium to high Glycaemic Index
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 dietOther
Also called glycemic index, glycaemic index, low glycemic carbohydrates, low glycaemic carbohydrates
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.
| Study group | Role | What they receive |
|---|---|---|
| Standard Care | Placebo comparator | Standard care dietary advice to emphasize high fiber foods with a moderate to high GI Receives: Other: Low GI diet |
| Low GI Diet | Experimental | Low GI dietary advice in addition to standard care Receives: Other: Standard Care |
What is being measured
The primary outcome is the main question the study is designed to answer.
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)
Measured: From randomization to delivery
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.
Measured: 1 week and 8 weeks postpartum
Secondary outcomes (51)
MAIN STUDY: Infant birth weight
Weight of the baby at delivery in grams.
Measured: At delivery
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)
Measured: From randomization to delivery
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.
Measured: From randomization to delivery
MAIN STUDY: Insulin prescription incidence
Proportion of women prescribed insulin during the intervention
Measured: From randomization to delivery
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.
Measured: From randomization to delivery
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.
Measured: From randomization to delivery
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.
Measured: From randomization to delivery
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.
Measured: From randomization to delivery
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.
Measured: From randomization to delivery
MAIN STUDY: Change in LDL oxidation at 4 weeks
Difference between LDL oxidation measured in fasting venous blood at randomization and 4 weeks.
Measured: Change from randomization in LDL oxidation at 4 weeks.
MAIN STUDY: LDL oxidation 6-8 weeks after delivery
LDL oxidation measured in fasting venous blood 6-8 weeks after delivery.
Measured: 6-8 weeks after delivery
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.
Measured: Change from randomization to 4 weeks
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.
Measured: Change in CRP from randomization at 4 weeks
MAIN STUDY: Post-partum CRP
Concentration of venous serum c-reactive protein 6-8 weeks after delivery.
Measured: 6-8 weeks after delivery
MAIN STUDY: Post-partum fasting serum glucose
Venous fasting serum glucose 6-8 weeks after delivery
Measured: 6-8 weeks after delivery
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).
Measured: 6-8 weeks after delivery
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.
Measured: 6-8 weeks after delivery
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.
Measured: 6-8 weeks after delivery
MAIN STUDY: Maternal weight gain
Difference between reported pre-pregnancy body weight and last body weight measured before delivery.
Measured: From pre-pregnancy to delivery: up to 9 months
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.
Measured: From randomization to delivery
MAIN STUDY: Change in infant weight
Difference between infant birthweight and weight 6-8 weeks after delivery.
Measured: Change in infant body weight from birth to 6- 8 weeks
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.
Measured: From randomization to 6- 8 weeks post-partum
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.
Measured: 1 week after delivery
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.
Measured: 6-8 weeks after delivery
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
Measured: Delivery to 6-8 weeks postpartum
MAIN STUDY: Change in infant body measurements from birth to 6-8 weeks post-partum
Weight, head circumference, and height/length
Measured: Change in infant body measurements from delivery to 6-8 weeks post-partum
MAIN STUDY: Infant APGAR score at delivery
Infant APGAR score at delivery as recorded in maternal medical chart.
Measured: Delivery
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.
Measured: Change from randomization to 4 weeks.
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.
Measured: 6-8 weeks after delivery
MAIN STUDY: Infant waist circumference at 6-8 weeks
Infant waist circumference at 6-8 weeks.
Measured: 6-8 weeks after delivery
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.
Measured: Change from randomization to delivery
MAIN STUDY: Maternal height at baseline
Maternal height at baseline
Measured: Baseline
MAIN STUDY: Maternal medical history
Maternal medical history
Measured: Baseline
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
Measured: Baseline to 6-8 weeks after delivery
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.
Measured: Difference between delivery and 6-8 weeks post-partum
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.
Measured: Baseline
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.
Measured: 6-8 weeks after delivery
MAIN STUDY: Length of time between delivery and maternal breast fullness
Length of time between delivery and maternal breast fullness.
Measured: Time after delivery
MAIN STUDY: Change in conjugated dienes at 4 weeks
Difference between conjugated dienes of plasma measured in venous serum at baseline and 4 weeks.
Measured: change from baseline to 4 weeks.
MAIN STUDY: Conjugated dienes post-partum
Conjugated dienes in fasting venous blood 6-8 weeks after delivery
Measured: 6-8 weeks after delivery
MAIN STUDY: Oxygen Radical Absorbance Capacity (ORAC) of venous plasma post-partum
ORAC measured in fasting venous blood 6-8 weeks after delivery
Measured: 6-8 weeks after delivery
MAIN STUDY: Change in full lipid profile at 4 weeks
Difference in full lipid profile of fasting venous blood at baseline and 4 weeks.
Measured: Change in full lipid profile of plasma from baseline at 4 weeks
MAIN STUDY: Full lipid profile post-partum
Full lipid profile of fasting venous blood at 6-8 weeks post-partum
Measured: 6-8 weeks after delivery
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.
Measured: Change from baseline to 6-8 weeks postpartum
MAIN STUDY: Infant feeding practices
Maternal infant feeding practices from delivery to 6-8 weeks postpartum
Measured: 6-8 weeks after delivery
MAIN STUDY: Participant satisfaction of baseline education class
Participant reactions and opinions on baseline education class using a face-validated, pre-tested questionnaire.
Measured: Baseline
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.
Measured: Change in GI knowledge from randomization to 6-8 weeks after delivery
MAIN STUDY: Participant knowledge of GI at baseline
Participant knowledge of GI at baseline (pre-education class)using a validated questionnaire.
Measured: Baseline
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.
Measured: Change in opinion from 2 weeks to 6-8 weeks after delivery
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.
Measured: From baseline to 6-8 weeks after delivery
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.
Measured: Change in behaviour from baseline (pre-class) to 6-8 weeks after delivery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 May 2012 (estimated)
- Study startOct 2011
- Primary completionSep 2015
- Study completionSep 2015
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (7)Papers the sponsor has linked to this study.
- Other trials for Gestational Diabetes MellitusStudies of the same condition, open and under way.
- More trials run by University of TorontoThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 2/3
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 99 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Toronto
- Sponsor type
- University, hospital or other
- Collaborators
- Canadian Diabetes Association, Canadian Institutes of Health Research (CIHR), Canadian Foundation for Dietetic Research (CFDR)
- Responsible party
- Principal investigator, Thomas Wolever, University of Toronto
- Investigators
- Thomas MS Wolever, MD, PhD, Principal investigator, University of Toronto/ St Michael's Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01589757
- Sponsor's protocol ID
- UofTORE26937
- Acronym
- GIinGDM
- Status last verified
- May 2016
- First submitted
- 19 Apr 2012
- Last updated
- 20 May 2016
- Results posted
- No
- Data monitoring committee
- No
Publications
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.
PubMed 9272613Ceriello 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.
PubMed 9545118Huang 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.
PubMed 15769103Saenz 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
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.
PubMed 22128211Wolever, TMS. The Glycaemic Index: A Physiological Classification of Dietary Carbohydrate. Ontario, Canada: CABI, 2006.
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.
PubMed 22254100
Study at a glance
From the registry record, last updated by the sponsor on 20 May 2016. Recruitment status is as the sponsor reported it: confirm with the study team.
- 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
- ClinicalTrials.gov ID
- NCT01589757
- Acronym / sponsor ID
- GIinGDM / UofTORE26937
- Conditions
- Gestational Diabetes Mellitus
- Keywords
- "glycaemic index", "glycemic index", hyperglycaemia, hyperglycemia, pregnancy, "dietary intervention", "education evaluation", antioxidant
- Phase
- Phase 2/3
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 99 participants (actual)
- Lead sponsor
- University of TorontoUniversity, hospital or other
- Collaborators
- Canadian Diabetes Association, Canadian Institutes of Health Research (CIHR), Canadian Foundation for Dietetic Research (CFDR)
- Study start
- Oct 2011
- Primary completion
- Sep 2015 (actual)
- Study completion
- Sep 2015 (actual)
- First posted
- 2 May 2012 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Standard Care | Placebo comparator | Other: Low GI dietStandard care dietary advice to emphasize high fiber foods with a moderate to high GI |
| Low GI Diet | Experimental | Other: Standard CareLow GI dietary advice in addition to standard care |
Who may qualify
- Ages
- 18 years and older
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- ≥ 18 years of age
- diagnosed with gestational diabetes mellitus (GDM) or impaired glucose tolerance of pregnancy (IGTP) according to Canadian Diabetes Association (CDA) criteria
- being followed within DIP (one of 4 sites)
- willing and able to give informed consent
- willing and able to comply with the study protocol
Key exclusion criteria (8 listed)
- 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.).
- known to have type 1 or type 2 DM prior to pregnancy
- known multi-fetal pregnancy at enrolment
- ≥ 33 weeks' gestation
- prescribed oral anti-hyperglycaemic medication
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Standard CareAlso: medium to high Glycaemic IndexStandard 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. | Other | Low GI Diet |
| Low GI dietAlso: glycemic index, glycaemic index, low glycemic carbohydrates, low glycaemic carbohydratesNutrition 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. | Other | Standard Care |
Primary outcome
MAIN STUDY: Percentage of postprandial self monitored blood glucose (SMBG) values within the target range
Time frame: From randomization to delivery
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)
SUB-STUDY (n=75): Oxygen Radical Absorbance Capacity (ORAC) (Antioxidant Capacity) of transitional and mature breast milk.
Time frame: 1 week and 8 weeks postpartum
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.
51 secondary outcomes
MAIN STUDY: Infant birth weight
Time frame: At delivery
MAIN STUDY: Percentage of self-monitored fasting glucose values within the target range
Time frame: From randomization to delivery
MAIN STUDY: Glucose variability
Time frame: From randomization to delivery
MAIN STUDY: Insulin prescription incidence
Time frame: From randomization to delivery
MAIN STUDY: Mean fasting glucose
Time frame: From randomization to delivery
MAIN STUDY: Mean postprandial glucose
Time frame: From randomization to delivery
MAIN STUDY: Mean post-breakfast glucose
Time frame: From randomization to delivery
MAIN STUDY: Mean post-lunch blood glucose
Time frame: From randomization to delivery
MAIN STUDY: Mean post-dinner blood glucose
Time frame: From randomization to delivery
MAIN STUDY: Change in LDL oxidation at 4 weeks
Time frame: Change from randomization in LDL oxidation at 4 weeks.
MAIN STUDY: LDL oxidation 6-8 weeks after delivery
Time frame: 6-8 weeks after delivery
MAIN STUDY: Change in Oxygen Radical Absorbance Capacity (ORAC) of plasma at 4 weeks
Time frame: Change from randomization to 4 weeks
MAIN STUDY: Change in c-reactive protein (CRP) at 4 weeks
Time frame: Change in CRP from randomization at 4 weeks
MAIN STUDY: Post-partum CRP
Time frame: 6-8 weeks after delivery
MAIN STUDY: Post-partum fasting serum glucose
Time frame: 6-8 weeks after delivery
MAIN STUDY: Post-partum serum glucose concentration 2 hours after consumption of 75g oral glucose (2hrPC serum glucose).
Time frame: 6-8 weeks after delivery
MAIN STUDY: Incidence of post-partum impaired glucose tolerance
Time frame: 6-8 weeks after delivery
MAIN STUDY: Incidence of post-partum diabetes mellitus
Time frame: 6-8 weeks after delivery
MAIN STUDY: Maternal weight gain
Time frame: From pre-pregnancy to delivery: up to 9 months
MAIN STUDY: Rate of maternal weight gain
Time frame: From randomization to delivery
MAIN STUDY: Change in infant weight
Time frame: Change in infant body weight from birth to 6- 8 weeks
MAIN STUDY & SUB-STUDY (n=75): Maternal dietary intake
Time frame: From randomization to 6- 8 weeks post-partum
SUB-STUDY (n=75): Concentration of vitamin C, E, and Beta-carotene in transitional breast milk
Time frame: 1 week after delivery
SUB-STUDY (n=75): Concentration of vitamin C, E, and Beta-carotene in mature breast milk
Time frame: 6-8 weeks after delivery
MAIN STUDY: Infant demographics
Time frame: Delivery to 6-8 weeks postpartum
MAIN STUDY: Change in infant body measurements from birth to 6-8 weeks post-partum
Time frame: Change in infant body measurements from delivery to 6-8 weeks post-partum
MAIN STUDY: Infant APGAR score at delivery
Time frame: Delivery
MAIN STUDY: Change in maternal blood pressure and resting pulse from randomization to 4 weeks
Time frame: Change from randomization to 4 weeks.
MAIN STUDY: Maternal blood pressure and resting pulse at 6-8 weeks post-partum
Time frame: 6-8 weeks after delivery
MAIN STUDY: Infant waist circumference at 6-8 weeks
Time frame: 6-8 weeks after delivery
MAIN STUDY: Change in ultrasound measurements from randomization to delivery.
Time frame: Change from randomization to delivery
MAIN STUDY: Maternal height at baseline
Time frame: Baseline
MAIN STUDY: Maternal medical history
Time frame: Baseline
MAIN STUDY: Maternal medical complications from baseline to 6-8 weeks post-partum
Time frame: Baseline to 6-8 weeks after delivery
MAIN STUDY: Change in maternal weight from delivery at 6-8 weeks post-partum
Time frame: Difference between delivery and 6-8 weeks post-partum
MAIN STUDY: Maternal pre-natal demographic information
Time frame: Baseline
MAIN STUDY: Maternal post-partum socio-demographic data related to infant feeding practices
Time frame: 6-8 weeks after delivery
MAIN STUDY: Length of time between delivery and maternal breast fullness
Time frame: Time after delivery
MAIN STUDY: Change in conjugated dienes at 4 weeks
Time frame: change from baseline to 4 weeks.
MAIN STUDY: Conjugated dienes post-partum
Time frame: 6-8 weeks after delivery
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 May 2016.
- Background: PubMed 9272613Ceriello 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.
- Background: PubMed 9545118Ceriello 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.
- Background: PubMed 15769103Huang 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.
- BackgroundSaenz 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
- Background: PubMed 22128211Elisia 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.
- BackgroundWolever, TMS. The Glycaemic Index: A Physiological Classification of Dietary Carbohydrate. Ontario, Canada: CABI, 2006.
- Background: PubMed 22254100Grant 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.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Thomas MS Wolever, MD, PhD principal investigator
University of Toronto/ St Michael's Hospital
4 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 2/3 study testing Low GI diet in people with Gestational Diabetes Mellitus, run by University of Toronto at 4 sites in Canada.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 20 May 2016. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 4 sites in Canada. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this combined phase mean?
Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.
Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
MAIN STUDY: Percentage of postprandial self monitored blood glucose (SMBG) values within the target range (time frame: From randomization to delivery). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT01589757, which also lists 7 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 20 May 2016.