COVID-19 studies are our top priority. For all other trials, there is a 4-week delay in processing a trial submitted/resubmitted to the ANZCTR and additional delays for updates of registered trials. We appreciate your patience.

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial registered on ANZCTR


Registration number
ACTRN12620000387921
Ethics application status
Approved
Date submitted
9/03/2020
Date registered
20/03/2020
Date last updated
20/03/2020
Date data sharing statement initially provided
20/03/2020
Type of registration
Prospectively registered

Titles & IDs
Public title
Should an evening snack be recommended in the management of gestational diabetes mellitus?
Scientific title
Bedtime snacks for gestational diabetes mellitus (GDM): Should an evening snack be recommended in the management of GDM?
Secondary ID [1] 300695 0
Nil known
Universal Trial Number (UTN)
U1111-1249-0970
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Gestational Diabetes Mellitus 316508 0
Condition category
Condition code
Metabolic and Endocrine 314752 314752 0 0
Diabetes
Reproductive Health and Childbirth 314901 314901 0 0
Fetal medicine and complications of pregnancy

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
ARM 1: a snack (i.e. greek yoghurt) consumed 30 minutes before bedtime every night for 6 weeks. The snack consists of 1 CHO exchange (15g of carbohydrate or ~60 calories of carbohydrate). The total calories of the snack is ~180 calories. Total carbohydrate exchange distribution throughout the day of 2,2,2,2,3,1 for breakfast, morning tea, lunch, afternoon tea, dinner and supper respectively.
ARM 2: a snack (i.e. flavoured yoghurt) consumed 30 minutes before bedtime every night for 6 weeks. The snack consists of 2 CHO exchange (30g of carbohydrate or ~120 calories of carbohydrate). The total calories of the snack is ~180 calories. Total carbohydrate exchange distribution throughout the day of 2,2,2,2,2,2 for breakfast, morning tea, lunch, afternoon tea, dinner and supper respectively.
The intervention will be delivered by a dietitian. Both groups will receive standard care which is the advice to consume 12 CHO exchanges per day, however the distribution of exchanges will vary depending on the treatment group.
Consumption of the bedtime snack will be recorded by participants using a check sheet.
Intervention code [1] 317020 0
Treatment: Other
Comparator / control treatment
The control group will not be advised to have a snack before bedtime. The control group will receive standard care which is the advice to consume 12 carbohydrate exchanges per day (as will arm 1 and arm 2). The 12 carbohydrate exchanges will be distributed as 2,2,3,2,3,0 for breakfast, morning tea, lunch, afternoon tea, dinner and supper respectively.
Control group
Active

Outcomes
Primary outcome [1] 323128 0
Change in fasting glucose determined by finger prick blood glucose monitor.
Timepoint [1] 323128 0
Daily throughout intervention including baseline and 6 weeks after intervention commencement.
Primary outcome [2] 323130 0
Change in the proportion of women prescribed insulin.
Timepoint [2] 323130 0
Baseline and 6 weeks after intervention commencement.
Primary outcome [3] 323279 0
Change in the dose of insulin prescribed to the participating women.
Timepoint [3] 323279 0
Baseline and 6 weeks after intervention commencement.
Secondary outcome [1] 380871 0
Change in postprandial breakfast glucose levels determined by a finger prick blood glucose monitor.
Timepoint [1] 380871 0
Baseline and 6 weeks after intervention commencement.
Secondary outcome [2] 380872 0
Change in total cholesterol determined by a plasma assay.
Timepoint [2] 380872 0
Baseline and 6 weeks after intervention commencement,
Secondary outcome [3] 380873 0
Change in triglycerides determined by a plasma assay.
Timepoint [3] 380873 0
Baseline and 6 weeks after intervention commencement.
Secondary outcome [4] 380874 0
Change in appetite determined by 100mm visual analogue scale.
Timepoint [4] 380874 0
Baseline and 6 weeks after intervention commencement.
Secondary outcome [5] 380875 0
Change in LDL-cholesterol determined by plasma assay.
Timepoint [5] 380875 0
Baseline and 6 weeks after intervention commencement.
Secondary outcome [6] 380876 0
Change in sleep behaviour determined by ActiGraph (advanced sleep features) accelerometer.
Timepoint [6] 380876 0
Baseline and 6 weeks after intervention commencement.
Secondary outcome [7] 380877 0
Change in body composition determined by bioelectrical impedance analysis.
Timepoint [7] 380877 0
Baseline and 6 weeks after intervention commencement.
Secondary outcome [8] 380880 0
Change in insulin levels determined by plasma assay.
Timepoint [8] 380880 0
Baseline and 6 weeks after intervention commencement.
Secondary outcome [9] 380882 0
Change in glucagon levels determined by plasma assay.
Timepoint [9] 380882 0
Baseline and 6 weeks after intervention commencement.
Secondary outcome [10] 380884 0
Change in leptin levels determined by plasma assay.
Timepoint [10] 380884 0
Baseline and 6 weeks after intervention commencement.
Secondary outcome [11] 380886 0
Change in ghrelin levels determined by plasma assay.
Timepoint [11] 380886 0
Baseline and 6 weeks after intervention commencement.
Secondary outcome [12] 380890 0
Gestational age of birth determined by hospital health records.
Timepoint [12] 380890 0
Assessed during hospital stay after birth (~48hr after birth)
Secondary outcome [13] 380891 0
Gender of baby, determined by hospital health records.
Timepoint [13] 380891 0
Assessed during hospital stay after birth (~48hr after birth)
Secondary outcome [14] 380892 0
Birth weight determined by hospital health records.
Timepoint [14] 380892 0
Assessed during hospital stay after birth (~48hr after birth)
Secondary outcome [15] 380893 0
Birth length determined by hospital health records.
Timepoint [15] 380893 0
Assessed during hospital stay after birth (~48hr after birth)
Secondary outcome [16] 380894 0
Method of delivery of the birth determined by hospital health records.
Timepoint [16] 380894 0
Assessed during hospital stay after birth (~48hr after birth)
Secondary outcome [17] 380895 0
Number of visits with dietitian determined by hospital health records.
Timepoint [17] 380895 0
Assessed during hospital stay after birth (~48hr after birth)
Secondary outcome [18] 381210 0
Number of visits with obstetrician determined by hospital health records.
Timepoint [18] 381210 0
Assessed during hospital stay after birth (~48hr after birth)
Secondary outcome [19] 381414 0
Change in fasting glucose determined by continuous glucose monitoring.
Timepoint [19] 381414 0
Baseline and 6 weeks after intervention commencement
Secondary outcome [20] 381415 0
Change in overnight glucose determined by continuous glucose monitoring.
Timepoint [20] 381415 0
Baseline and 6 weeks after intervention commencement.

Eligibility
Key inclusion criteria
Referral to the Illawarra Diabetes Service for GDM management.
Diagnosed with GDM (physician, antenatal clinic or blood test).
Singleton pregnancy.
Able to start intervention between 28-30 weeks gestation.
Minimum age
18 Years
Maximum age
No limit
Gender
Females
Can healthy volunteers participate?
No
Key exclusion criteria
Allergies or intolerance to components in dairy (i.e. lactose).
High-risk pregnancy (i.e. twins, drug or alcohol abuse, chronic health problems, or pregnancy complications).

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation is not concealed
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
A computerised sequence generator will be used to randomise participants into the 3 groups. Randomisation will be stratified by insulin use.
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?



The people analysing the results/data
Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint(s)
Efficacy
Statistical methods / analysis
Based on pilot data, a sample size calculation performed using G*Power software estimated that 34 participants are needed per group (n=102) to achieve 80% power required to detect a clinically meaningful 0.4mmol/L2 difference in fasting glucose (d=0.05) between snack and no snack conditions (a<0.05). Accounting for a dropout rate of 15% a total of 117 participants will be recruited.
Data will first be assessed for normality using histograms and Q-Q plots of residuals. One-way repeated measures ANOVA will be used to analyse all outcome variables, and post-hoc tests will be performed using Tukey's HSD. All analysis will be conducted with SPSS software.

Recruitment
Recruitment status
Not yet recruiting
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
NSW
Recruitment postcode(s) [1] 29612 0
2500 - Wollongong

Funding & Sponsors
Funding source category [1] 305138 0
University
Name [1] 305138 0
Illawarra Health and Medical Research Institute
Address [1] 305138 0
Building 32, University of Wollongong, Northfields Ave, NSW 2522
Country [1] 305138 0
Australia
Primary sponsor type
University
Name
University of Wollongong
Address
University of Wollongong
Northfields Ave, Wollongong NSW 2522
Country
Australia
Secondary sponsor category [1] 305497 0
Government body
Name [1] 305497 0
Illawarra and Shoalhaven Local Health District
Address [1] 305497 0
Illawarra Diabetes Service, 304 Crown St, Wollongong NSW 2500
Country [1] 305497 0
Australia

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 305507 0
Joint University of Wollongong and Illawarra Shoalhaven Local Health District Health and Medical Human Research Ethics Committee
Ethics committee address [1] 305507 0
University or Wollongong
Northfields Ave, Wollongong NSW 2522
Ethics committee country [1] 305507 0
Australia
Date submitted for ethics approval [1] 305507 0
11/11/2019
Approval date [1] 305507 0
25/02/2020
Ethics approval number [1] 305507 0
2019/ETH13557

Summary
Brief summary
GDM is the fastest growing type of diabetes in Australia, affecting approximately 1 in every 7 pregnancies. In the Illawarra Shoalhaven Local Health District (ISLHD) ~840 women per year attend the diabetes clinic for treatment/management of GDM. Here, there has been a significant increase in the number of GDM women requiring treatment for fasting hyperglycaemia. This is both because of an increased prevalence (overweight/obesity, gestational age of mother) and because of a lowering of the diagnostic criteria following results from the Hyperglycaemia and Adverse Pregnancy Outcomes (HAPO) study. Despite this, there is no clear treatment approach for fasting hyperglycaemia.
Elevated nocturnal (overnight) glucose levels, manifesting as elevated fasting hyperglycaemia, are due to a combination of insulin resistance and insufficiency. Consuming a meal/snack prior to bed can help maintain insulin levels across the night. However, despite popular advice from health care practitioners to consume a bedtime snack to help control fasting (and overnight) glucose, few studies exist to support this recommendation. Pilot data from a recent study conducted in our lab showed that 3-days of consuming a high-protein, low-carbohydrate snack consumed 30 minutes prior to bed significantly improves fasting glucose, insulin sensitivity and nocturnal hyperglycaemia compared to a moderate-carbohydrate snack or no bedtime snack in 15 patients with type 2 diabetes. The amount and glycemic index of carbohydrates in the last meal before bedtime has the largest impact on fasting and nocturnal hyperglycaemia. Therefore, if a snack should be consumed, minimising the carbohydrate appears to be of importance.
Given the increasing prevalence of GDM and the complications of fasting hyperglycaemia for mother and baby (including risk for future diabetes), a safe, easily implemented and cost-effective intervention is urgently needed.
The main objective of this research is to test whether consuming a snack 30 minutes prior to bed is a viable treatment option for fasting hyperglycaemia in women with GDM.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 100606 0
Dr Monique Francois
Address 100606 0
School of Medicine, University of Wollongong
NSW 2522, Australia
Ph 4221 5136, RM 41.330
Country 100606 0
Australia
Phone 100606 0
+61 2 42215136
Fax 100606 0
Email 100606 0
francois@uow.edu.au
Contact person for public queries
Name 100607 0
Dr Monique Francois
Address 100607 0
School of Medicine, University of Wollongong
NSW 2522, Australia
Ph 4221 5136, RM 41.330
Country 100607 0
Australia
Phone 100607 0
+61 2 42215136
Fax 100607 0
Email 100607 0
francois@uow.edu.au
Contact person for scientific queries
Name 100608 0
Dr Monique Francois
Address 100608 0
School of Medicine, University of Wollongong
NSW 2522, Australia
Ph 4221 5136, RM 41.330
Country 100608 0
Australia
Phone 100608 0
+61 2 42215136
Fax 100608 0
Email 100608 0
francois@uow.edu.au

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
What supporting documents are/will be available?
No other documents available
Summary results
No Results