Clinical trial NCT01589757: MAIN STUDY: Low Glycaemic Index (GI) Diet in the Management of GDM SUB-STUDY: The Breast Milk Sub-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
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE2
PHASE3
Conditions: Gestational Diabetes Mellitus
Keywords: "glycaemic index"
"glycemic index"
hyperglycaemia
hyperglycemia
pregnancy
"dietary intervention"
"education evaluation"
antioxidant
"Impaired Glucose Tolerance of Pregnancy"
"Gestational Diabetes Mellitus"
"Breast Milk"
Lead sponsor: University of Toronto
Sponsor class: OTHER
Collaborators: name: Canadian Diabetes Association
name: Canadian Institutes of Health Research (CIHR)
name: Canadian Foundation for Dietetic Research (CFDR)
First posted: 2012-05-02
Enrollment: 99
Sex: FEMALE
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

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.

Eligibility criteria: 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

Primary outcomes:
measure: MAIN STUDY: Percentage of postprandial self monitored blood glucose (SMBG) values within the target range
timeFrame: From randomization to delivery
measure: SUB-STUDY (n=75): Oxygen Radical Absorbance Capacity (ORAC) (Antioxidant Capacity) of transitional and mature breast milk.
timeFrame: 1 week and 8 weeks postpartum
Secondary outcomes:
measure: MAIN STUDY: Infant birth weight
timeFrame: At delivery
measure: MAIN STUDY: Percentage of self-monitored fasting glucose values within the target range
timeFrame: From randomization to delivery
measure: MAIN STUDY: Glucose variability
timeFrame: From randomization to delivery
measure: MAIN STUDY: Insulin prescription incidence
timeFrame: From randomization to delivery
measure: MAIN STUDY: Mean fasting glucose
timeFrame: From randomization to delivery
measure: MAIN STUDY: Mean postprandial glucose
timeFrame: From randomization to delivery
measure: MAIN STUDY: Mean post-breakfast glucose
timeFrame: From randomization to delivery
measure: MAIN STUDY: Mean post-lunch blood glucose
timeFrame: From randomization to delivery
measure: MAIN STUDY: Mean post-dinner blood glucose
timeFrame: From randomization to delivery
measure: MAIN STUDY: Change in LDL oxidation at 4 weeks
timeFrame: Change from randomization in LDL oxidation at 4 weeks.
measure: MAIN STUDY: LDL oxidation 6-8 weeks after delivery
timeFrame: 6-8 weeks after delivery
measure: MAIN STUDY: Change in Oxygen Radical Absorbance Capacity (ORAC) of plasma at 4 weeks
timeFrame: Change from randomization to 4 weeks
measure: MAIN STUDY: Change in c-reactive protein (CRP) at 4 weeks
timeFrame: Change in CRP from randomization at 4 weeks
measure: MAIN STUDY: Post-partum CRP
timeFrame: 6-8 weeks after delivery
measure: MAIN STUDY: Post-partum fasting serum glucose
timeFrame: 6-8 weeks after delivery
measure: MAIN STUDY: Post-partum serum glucose concentration 2 hours after consumption of 75g oral glucose (2hrPC serum glucose).
timeFrame: 6-8 weeks after delivery
measure: MAIN STUDY: Incidence of post-partum impaired glucose tolerance
timeFrame: 6-8 weeks after delivery
measure: MAIN STUDY: Incidence of post-partum diabetes mellitus
timeFrame: 6-8 weeks after delivery
measure: MAIN STUDY: Maternal weight gain
timeFrame: From pre-pregnancy to delivery: up to 9 months
measure: MAIN STUDY: Rate of maternal weight gain
timeFrame: From randomization to delivery
measure: MAIN STUDY: Change in infant weight
timeFrame: Change in infant body weight from birth to 6- 8 weeks
measure: MAIN STUDY & SUB-STUDY (n=75): Maternal dietary intake
timeFrame: From randomization to 6- 8 weeks post-partum
measure: SUB-STUDY (n=75): Concentration of vitamin C, E, and Beta-carotene in transitional breast milk
timeFrame: 1 week after delivery
measure: SUB-STUDY (n=75): Concentration of vitamin C, E, and Beta-carotene in mature breast milk
timeFrame: 6-8 weeks after delivery
measure: MAIN STUDY: Infant demographics
timeFrame: Delivery to 6-8 weeks postpartum
measure: MAIN STUDY: Change in infant body measurements from birth to 6-8 weeks post-partum
timeFrame: Change in infant body measurements from delivery to 6-8 weeks post-partum
measure: MAIN STUDY: Infant APGAR score at delivery
timeFrame: Delivery
measure: MAIN STUDY: Change in maternal blood pressure and resting pulse from randomization to 4 weeks
timeFrame: Change from randomization to 4 weeks.
measure: MAIN STUDY: Maternal blood pressure and resting pulse at 6-8 weeks post-partum
timeFrame: 6-8 weeks after delivery
measure: MAIN STUDY: Infant waist circumference at 6-8 weeks
timeFrame: 6-8 weeks after delivery
measure: MAIN STUDY: Change in ultrasound measurements from randomization to delivery.
timeFrame: Change from randomization to delivery
measure: MAIN STUDY: Maternal height at baseline
timeFrame: Baseline
measure: MAIN STUDY: Maternal medical history
timeFrame: Baseline
measure: MAIN STUDY: Maternal medical complications from baseline to 6-8 weeks post-partum
timeFrame: Baseline to 6-8 weeks after delivery
measure: MAIN STUDY: Change in maternal weight from delivery at 6-8 weeks post-partum
timeFrame: Difference between delivery and 6-8 weeks post-partum
measure: MAIN STUDY: Maternal pre-natal demographic information
timeFrame: Baseline
measure: MAIN STUDY: Maternal post-partum socio-demographic data related to infant feeding practices
timeFrame: 6-8 weeks after delivery
measure: MAIN STUDY: Length of time between delivery and maternal breast fullness
timeFrame: Time after delivery
measure: MAIN STUDY: Change in conjugated dienes at 4 weeks
timeFrame: change from baseline to 4 weeks.
measure: MAIN STUDY: Conjugated dienes post-partum
timeFrame: 6-8 weeks after delivery
measure: MAIN STUDY: Oxygen Radical Absorbance Capacity (ORAC) of venous plasma post-partum
timeFrame: 6-8 weeks after delivery
measure: MAIN STUDY: Change in full lipid profile at 4 weeks
timeFrame: Change in full lipid profile of plasma from baseline at 4 weeks
measure: MAIN STUDY: Full lipid profile post-partum
timeFrame: 6-8 weeks after delivery
measure: MAIN STUDY: Change in incidence and severity of symptoms from baseline to 6-8 weeks postpartum
timeFrame: Change from baseline to 6-8 weeks postpartum
measure: MAIN STUDY: Infant feeding practices
timeFrame: 6-8 weeks after delivery
measure: MAIN STUDY: Participant satisfaction of baseline education class
timeFrame: Baseline
measure: MAIN STUDY: Change in participant knowledge of GI from baseline to 6-8 weeks after delivery
timeFrame: Change in GI knowledge from randomization to 6-8 weeks after delivery
measure: MAIN STUDY: Participant knowledge of GI at baseline
timeFrame: Baseline
measure: MAIN STUDY: Change in participant opinion on availability and acceptability of study diet foods
timeFrame: Change in opinion from 2 weeks to 6-8 weeks after delivery
measure: MAIN STUDY: Difference in dietary GI between study groups.
timeFrame: From baseline to 6-8 weeks after delivery
measure: MAIN STUDY: Change in behaviour from baseline (pre-class) to 6-8 weeks after delivery.
timeFrame: Change in behaviour from baseline (pre-class) to 6-8 weeks after delivery
Other outcomes:
Locations:
city: Hamilton
country: Canada
facility: MAIN STUDY ONLY: St Joseph's Heathcare Hamilton, 50 Charlton Avenue East
state: Ontario
city: Toronto
country: Canada
facility: St. Michael's Hospital
state: Ontario
city: Toronto
country: Canada
facility: Mt Sinai Hospital
state: Ontario
city: Toronto
country: Canada
facility: Sunnybrook Health Sciences Centre
state: Ontario
Study officials:
affiliation: University of Toronto/ St Michael's Hospital
name: Thomas MS Wolever, MD, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: 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.
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. doi: 10.1002/(SICI)1096-9136(199803)15:33.0.CO;2-V. No abstract available.
citation: 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.
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
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.
citation: Wolever, TMS. The Glycaemic Index: A Physiological Classification of Dietary Carbohydrate. Ontario, Canada: CABI, 2006.
citation: 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.