Condition category
Nutritional, Metabolic, Endocrine
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims:
Childhood obesity has increased globally over the last two decades and it is linked to an increase in the diagnosis of type 2 diabetes (T2D) in childhood and adolescence. T2D is a condition that was previously only diagnosed in adults and was very rare in children. T2D is associated with high blood glucose levels and with other significant health problems, such as increased risk of heart problems, eye problems, kidney problems, nerve problems and premature death. It is therefore important to try to prevent the onset of T2D in obese children and adolescents.
Metformin is a drug that reduces the risk for T2D in obese adults, but the evidence in obese children and young people is inconclusive. The aims of the MOCA trial were to find out how well metformin works in obese children and adolescents.

Who can participate?
One hundred and fifty-one obese children and young people took part in the trial with 74 in the metformin group and 77 in the dummy (placebo) group. 67.5% were female, and 23.8% were British Asian or Afro-Caribbean. The age range was 8-18 years, with an average age of 13.7 years.

What does the study involve?
The MOCA trial was a prospective clinical trial over six months, where the participants were put into two groups randomly by chance. One group was given treatment with metformin and one group was given a dummy pill (placebo). Neither the participant or study investigator knew whether the participant was taking the metformin or placebo. All the participants were obese and they visited the trial centre at the start of the trial, after 3 months treatment and after 6 months treatment (the end). At each visit they had blood tests done and their weight and height was measured so that their body mass index (BMI) could be calculated (weight in kg/height in m2). The BMI was then adjusted for age and sex to give the body mass index standard deviation score (BMI-SDS).

What are the possible benefits and risks of participating?
Benefits of participating include a potential reduction in long-term risk of T2D and associated health problems. The risks associated with participating were small as metformin is safe and well tolerated with minimal side-effects in obese children and adolescents.

Where is the study run from?
The trial took place in six UK paediatric endocrine centres.

When is the study starting and how long is it expected to run for?
The study began in January 2005 and ended in June 2009.

Who is funding the study?
Central Manchester University Hospitals NHS Foundation Trust and the Child Growth Foundation UK.

Who is the main contact?
Peter E Clayton MD MRCP FRCPCH

Trial website

Contact information



Primary contact

Dr Peter Clayton


Contact details

Manchester Academic Health Sciences Centre
Paediatric Endocrinology
5th Floor (Research)
Royal Manchester Children's Hospital
Oxford Road
M13 9WL
United Kingdom
+ 44 (0)161 701 6949

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title



Study hypothesis

To study the effects of metformin in children and adolescents with fasting hyperinsuliaemia and/or impaired glucose tolerance.

Ethics approval

Added 16 December 2008: Salford and Trafford Research Ethics Committee, 13/09/2004, REC reference no: 04/Q1404/65.

Study design

Multicentre prospective randomised placebo controlled

Primary study design


Secondary study design

Randomised controlled trial

Trial setting

Not specified

Trial type


Patient information sheet

'Not available in web format, please use the contact details below to request a patient information sheet


Nutritional, Metabolic, Endocrine: Obesity


Previous interventions:
1. Metformin (500mg)
2. Placebo

Current interventions as of 15/12/2008:
1. Metformin 1g mane, 500mg nocte
2. Placebo

Intervention type



Not Specified

Drug names


Primary outcome measure

Reduction in BMI SDS.

Secondary outcome measures

Added 16 December 2008: fasting and 2 hr insulin and glucose levels on OGTT, measures of insulin resistance, fasting lipids, CRP, adiponectin, leptin, resistin, blood pressure.

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

Prior to 16 December 2008:
80 patients aged between 9-18 years old

As of 16 December 2008:
1. Pubertal and post-pubertal children : Fasting insulin > 26 mIU/l
2. Pre-pubertal children : Fasting insulin > 15 mIU/l
3. 120 minute insulin > 89 mIu/l
Impaired glucose tolerance ie: OGTT 2hr plasma glucose value > or = 7.8 to <11.1 (+/- impaired fasting glucose > or = 6.1 to < 7)

Participant type


Age group



Not Specified

Target number of participants

40 in each group, 80 in total.

Participant exclusion criteria

Added 16 December 2008:

1. Glycosuria
2. Ketonuria
3. Other chronic illness or chromosomal abnormality or syndrome eg. Prader-Willi, Turner’s syndrome, hypothyroidism
4. Renal insufficiency
5. Hepatic dysfunction (raised ALT >2 SDS above mean)
6. Chronic diarrhoea
7. Previous episode lactic acidosis

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

Manchester Academic Health Sciences Centre
M13 9WL
United Kingdom

Sponsor information


Record Provided by the NHSTCT Register - 2006 Update - Department of Health

Sponsor details

The Department of Health
Richmond House
79 Whitehall
United Kingdom
+44 (0)20 7307 2622

Sponsor type




Funder type


Funder name

Central Manchester and Manchester Children's University Hospitals NHS Trust (UK) - NHS R&D Support Funding

Alternative name(s)

Funding Body Type

Funding Body Subtype


Funder name

Child Growth Foundation

Alternative name(s)

Funding Body Type

Funding Body Subtype


Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

1. 2012 results in

Publication citations

  1. Results

    Kendall D, Vail A, Amin R, Barrett T, Dimitri P, Ivison F, Kibirige M, Mathew V, Matyka K, McGovern A, Stirling H, Tetlow L, Wales J, Wright N, Clayton P, Hall C, Metformin in obese children and adolescents: the MOCA trial., J. Clin. Endocrinol. Metab., 2013, 98, 1, 322-329, doi: 10.1210/jc.2012-2710.

Additional files

Editorial Notes