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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Date data sharing statement initially provided
Type of registration
Prospectively registered

Titles & IDs
Public title
Adolescent Weight Loss Surgery study
Scientific title
A pilot study to evaluate the benefit of intensive lifestyle intervention (low calorie diet and exercise) with or without bariatric (weight-reduction) surgery in high-risk adolescents with morbid obesity.
Secondary ID [1] 300770 0
Nil Known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Morbid obesity 316619 0
pre-diabetes type 2 diabetes 316620 0
type 2 diabetes 316621 0
Condition category
Condition code
Metabolic and Endocrine 314854 314854 0 0
Diet and Nutrition 314946 314946 0 0

Study type
Description of intervention(s) / exposure
The purpose of this pilot study is to investigate the effect of intensive lifestyle intervention with or without bariatric (weight-reduction) surgery on the incidence of pre-diabetes and diabetes in a cohort of high-risk morbidly obese adolescent subjects.

After the screening and baseline assessments and confirmed diagnosis of diabetes/pre-diabetes, consented participants will receive a 12 week weight-loss regimen comprising Very Low Calorie Diet (VLCD) based on the Optifast weight loss Programme, psychological assessment and psychiatric evaluation if required, family counselling, cultural support, and dietetic assessment/counselling. This will be followed by a weight maintenance programme which has been tailored for the study. These programmes will be provided by the Diabetes Foundation Aotearoa team comprising diabetes nurse, dietician, health psychologist and support staff.

12 week weight-loss regimen comprises:
Frequency: Optifast™programme group sessions conducted over a 12 week period, every 2 weeks for 1 hour in the evenings at the Manukau Super Clinic.
Mode: These group sessions are face-to-face and include the participant and a support person(s). A private facebook group will be set up and the sessions recorded for those participants unable to attend.
The programme is as follows:
Weeks 1-2, 4 and 6 are – INTENSIVE
Weeks 8, 10, and 12 are TRANSITION
Note: the Koha (reimbursement to say thank you) will be in the form of a supermarket or petrol voucher and provided at every session.

Curriculum for Optifast™ Program:
- Overview of what to expect from the /program
- How to start.
- Tips, tricks and surviving (including not self-sabotaging/pantry audit)
- Drinking, vegetables, what’s allowed
- Gentle activity session
- What to do to stay on track, what to do when fall off track
- Side effects, how to manage them
- Contact details, motivation and advice between meetings
- Provision of Initial Optifast™ supplies for 21-28 days.
- Opportunity to meet one- on- one with one of the nutritionist/dietitian/health psychologist.
- Questions and answers
- Facebook page introduction
- Program details

Weeks 4 to 6 – INTENSIVE
- Programme as for week 1-2 and including:
- Where we are in the program
- How are people going
- Share tips/hints/success stories
- Gentle activity session
- Weigh in (private)
- Mini consult with dietician/nutritionist/health psychologist
- Role model/success story (if suitable individual can be available)
At this second group meeting, individuals will be provided with
- Optifast™ Supplies for 14 days (if not self-ordering through some system yet to be set up)
- Other supplies as, Psyllium
- Questions and answers
- Next steps

Week 8, 10 and 12 TRANSITION
- Introduction of 1 meal back into the day. This session will provide further information, motivation, and support.
The core content of teaching will be the same as previous sessions and also include :
- Where we are in the program
- Time to start transitioning back towards healthy eating
- What a healthy meal looks like (starter healthy eating information, relevant to program but setting the stage for general living later)

After 12 weeks, those participants who meet criteria for surgery will be offered a laparoscopic gastric sleeve or gastric bypass procedure, which will be done by Dr Richard Babor (General Surgeon) at the Manukau Surgical Centre in Auckland. An estimated time for the procedure would be up to an hour.
Health Psychologist assessment at week 12.
Format: 1-hour individual session with Health Psychologist for all participants at Manukau Superclinic outpatient clinic. Health Psychologist will formally assess mental state and participant’s readiness to have bariatric surgery for those participants who qualify (e.g. age equal to 16 years)

Medical assessments will be carried out by the study investigator at baseline and weeks 24-36.and psychological support provided by Health Psychologists associated with the Adolescent Diabetes Clinic.

Weight maintenance programme will begin for those participants who do not fulfil the criteria for surgery and will begin at week 12, through weeks 24, 36 and 48.

Curriculum of Weight Maintenance Program:
Months 1, 3 and 6 Programme Overview
Outcome: This session consolidates new habits and skills
Format: 1-hour evening group session at Manukau Superclinic
The core content of teaching will include:
- Overview of what to expect/program
- How are people doing with their new life
- More on healthy diet for normal living
- Benefits of Physical activity and what does it mean to different people
- Physical activity session
- Weight
- Other to be determined
- At this group meeting, individuals will be provided with
- Voucher for petrol or groceries to thank participants for attending
- Opportunity to meet one-on-one with one of the nutritionist, dietitian, sports specialist.
- Questions and answers

Outcome: This session evaluates health status & identifies any new health issues
Format: 20-minute session with Diabetes Specialist for all participants at Manukau Superclinic outpatient clinic. Diabetes Specialist will review clinical condition and management of diabetes
Intervention code [1] 317095 0
Intervention code [2] 317096 0
Treatment: Surgery
Comparator / control treatment
Controls will be those participants who do not meet selection criteria for a bariatric procedure after the 12 week VLCD regimen. Control participants will continue with intensive lifestyle intervention/weight loss maintenance programme until the end of the study.
Control group

Primary outcome [1] 323199 0
Composite primary outcome:
Incidence of diabetes and pre-diabetes as determined by a fasting oral glucose tolerance test.
Timepoint [1] 323199 0
After baseline (pre-surgery) and at week 52 (end of study)
Secondary outcome [1] 381156 0
Weight change measured by digital scales
Timepoint [1] 381156 0
Weight change will be measured at each study visit.
Secondary outcome [2] 381157 0
Glycaemic control as measured by glycated haemoglobin level (HbA1c) using a DCA machine
Timepoint [2] 381157 0
Screening (pre-surgery), and weeks 24, 52 (post surgery)
Secondary outcome [3] 381158 0
Mean blood pressure as measured by the mean of sitting systolic & diastolic BP levels using a digital machine (Dynamap).
Timepoint [3] 381158 0
Baseline, weeks 1,12, pre- surgery and then post-surgery during follow-up at weeks1,12,36,52
Secondary outcome [4] 381159 0
Dyslipidaemia measured using blood test and laboratory evaluation to determine fasting cholesterol, HDL-c, and triglyceride levels
Timepoint [4] 381159 0
Baseline, day of surgery for those having surgery, weeks 24 and 52
Secondary outcome [5] 381160 0
Quality of life as measured by the IWQOL-Lite (Impact of Weight Reduction Questionnaire) and SF-36.
Timepoint [5] 381160 0
baseline, the post surgery weeks 1,12,24,36,52

Key inclusion criteria
1. Be aged between 15 years 9 months and 18 years inclusive
2. Have been diagnosed with morbid obesity defined as a body mass index (BMI) >35 kg/m2 at the baseline visit.
3. Have pre-diabetes or type 2 diabetes mellitus as confirmed by oral glucose tolerance test at the baseline visit.
4. Provide written informed consent to participate in the study
Minimum age
189 Months
Maximum age
18 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
1. History of type 1 diabetes defined as age of onset <20 years and/or history of continuous treatment with insulin since diagnosis and/or positive antibodies to glutamic acid decarboxylase [GAD] or islet tyrosine phosphatase 2 [IA2] at baseline.
2. History of drug or alcohol abuse
3. Pregnancy
4. Serious co-morbid conditions that are likely to affect survival
5. Any other disease or condition which in the opinion of the investigator could make them unsuitable for entry.

Study design
Purpose of the study
Allocation to intervention
Non-randomised 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)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?

Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
Inferential and simple descriptive statistics, graphs, and subject listings will be used to summarise the data.

Recruitment status
Not yet recruiting
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment outside Australia
Country [1] 22434 0
New Zealand
State/province [1] 22434 0

Funding & Sponsors
Funding source category [1] 305229 0
Name [1] 305229 0
Freemasons Foundation Potter Trust
Address [1] 305229 0
Unit 2 – 22 Tacy Street
Kilbirnie, Wellington 6022
Country [1] 305229 0
New Zealand
Primary sponsor type
Commercial sector/Industry
Middlemore Clinical Trials
100 Hospital Rd
Auckland 2025
New Zealand
Secondary sponsor category [1] 305587 0
Name [1] 305587 0
Freemasons Foundation Potter Trust
Address [1] 305587 0
Unit 2 – 22 Tacy Street
Kilbirnie, Wellington 6022
Country [1] 305587 0
New Zealand
Secondary sponsor category [2] 306096 0
Name [2] 306096 0
Perpetual Guardian Trust
Address [2] 306096 0
343 Remuera Rd
Auckland 1050
Country [2] 306096 0
New Zealand

Ethics approval
Ethics application status
Ethics committee name [1] 305575 0
Northern B HDEC
Ethics committee address [1] 305575 0
Health and Disability Ethics Committees
Ministry of Health
133 Molesworth Street
PO Box 5013
Ethics committee country [1] 305575 0
New Zealand
Date submitted for ethics approval [1] 305575 0
Approval date [1] 305575 0
Ethics approval number [1] 305575 0

Brief summary
The aim of this pilot study is to investigate the effect of bariatric (weight-reduction) surgery (laparoscopic sleevegastrectomy or gastric bypass)on weight loss and health status in a cohort of morbidly obese adolescent diabetic subjects. This study will run for a maximum of 1.5 years consisting of: 6-months pre-assessment / rehabilitation support; and follow up at one year. Each rehabilitation plan will be developed on a case-by-case basis utilising a “pool” of resources / providers as required. This pool of services will include:
• Psychological assessment / support
• Health literacy
• Cultural support
• Dietetic / nutritional support
• Peer support / focus group meetings
The aim is to recruit ten participants into the surgery group and ten into the control group.

The control group will be formed by those participants who do not meet selection criteria for a bariatric procedure after the 12 week VLCD regimen. Control participants will continue with intensive lifestyle intervention/weight loss maintenance programme until the end of the study.

Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 100826 0
Dr Brandon Orr Walker
Address 100826 0
Middlemore Hospital
100 Hospital Rd
Auckland 2025
Country 100826 0
New Zealand
Phone 100826 0
+64 9 2760000
Fax 100826 0
+64 9 2503838
Email 100826 0
Contact person for public queries
Name 100827 0
Dr Brandon Orr Walker
Address 100827 0
Middlemore Hospital
100 Hospital Rd
Auckland 2025
Country 100827 0
New Zealand
Phone 100827 0
+64 9 2760000
Fax 100827 0
+64 9 2503838
Email 100827 0
Contact person for scientific queries
Name 100828 0
Dr Brandon Orr Walker
Address 100828 0
Middlemore Hospital
100 Hospital Rd
Auckland 2025
Country 100828 0
New Zealand
Phone 100828 0
+64 9 2760000
Fax 100828 0
+64 9 2503838
Email 100828 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
What data in particular will be shared?
individual data of published results
When will data be available (start and end dates)?
data available from 2022 with no end date.
Available to whom?
only researchers who provide a methodologically sound proposal, case-by-case basis at the discretion of the study investigators
Available for what types of analyses?
only to achieve the aims in the approved proposal
How or where can data be obtained?
Access will subject to approvals by Principal Investigator (
What supporting documents are/will be available?
No other documents available
Summary results
No Results