Condition category
Nervous System Diseases
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting
Publication status

Plain English Summary

Not provided at time of registration

Trial website

Contact information



Primary contact

Prof Stephan Rössner


Contact details

Obesity Unit
Karolinska University Hospital (Huddinge)

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Effects of a very low calorie diet (VLCD) induced weight loss on obstructive sleep apnoea syndrome (OSAS): a randomised controlled trial


Study hypothesis

Lifestyle modification, particularly weight loss, has been advocated as a treatment modality for obstructive sleep apnoea syndrome (OSAS). Surprisingly, there is a lack of well-conducted clinical trials; available studies have either been small and/or non-randomised. One reason could be that it has become popular to use devices such as continuous positive airway pressure (CPAP) or mandible retraction devices as mechanical tools rather than try to address the underlying problem, which generally is excess fatness in the throat area. In a report, from the International Diabetes Federation investigating the association between type 2 diabetes and sleep- disordered breathing, a number of recommendations were given. Apart from increased awareness and improved clinical practice the working party strongly suggested "appropriately powered randomised control trials of weight loss in patients with OSAS and diabetes, including the use of anti-obesity medication". The party also suggest the development of treatment programmes which are easier to use and cheaper than CPAP. In discussions with sleep apnoea experts in Sweden and the review of the literature have convinced us that there is a need for a well randomised executed study evaluating the effects of weight loss on sleep apnoea and associated sleep variables.

Ethics approval

The Regional Ethics Committee, Stockholm, approved on 28/11/2008 (ref: 2008/1634-31)

Study design

Randomised open placebo-controlled trial

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type


Patient information sheet

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


Obstructive sleep apnoea syndrome


Subjects will be randomly assigned to a VLCD treatment (intervention) or a control group (waiting list).

During 9 weeks the patients allocated to the intervention group will follow a VLCD-programme with 7 weeks of VLCD and 2 weeks of stabilisation. During the VLCD period the patients will receive 554 kcal per day consisting of 4 doses of commercial diet preparation (The Cambridge Diet, Cambridge Health & Weight Plan, UK). In the stabilisation phase the subjects will gradually supplement the Cambridge meals with selected foods. The patients will get an scheme from the dietician on how to reintroduce the conventional food in structured way. The allowed energy intake for each day will be specified. At the end of week 9 the patients should have reached an energy intake of 1800 kcal/day. The stabilisation phase will help to ensure long-term weight maintenance and to prevent short-term weight regain.

The control subjects will be placed on a waiting list and will be offered the same treatment as the intervention group at the end of the 9-week study period.

Both groups will after completing the VLCD period enter a weight maintenance programme in which they will receive conventional diet and exercise behaviour modification treatment at the Obesity Unit for 1 year duration. Sleep registrations will be conducted at baseline and after 9 weeks in the VLCD- and control group. The measurements will also be repeated after 1 year in the completers, i.e. the patients that completed the VLCD-period and the weight maintenance programme.

Intervention type



Not Applicable

Drug names

Primary outcome measure

Improvement of OSAS defined by AHI at 9 weeks (group-time interaction). Sleep registrations will be performed in duplicate with a seven channel home polygraphy equipment (WATCH_PAT 100, Itamar Medical Ldt, and Caesarea, Israel). Channels are for snoring, body position, peripheral arterial tone (PAT), pulse, oximetry, actigraphy and sleep staging. Respiratory Disturbance Index (RDI), AHI, sleep quality and quantity are derived from the PAT-signal, oximetry and actigraphy by a well defined and validated algorithm.

Secondary outcome measures

1. To evaluate the association between concentration of ketone bodies in the blood and euphoria during weight loss and to measure, anthropometry, metabolic markers, blood pressure, physical activity, quality of life and daytime sleepiness. Mean changes between groups (intervention and control group) between baseline and endpoint will be investigated for all variables. Clinical examinations will be conducted at screening, baseline, week 1, 3, 5, 7, 9 in the VLCD- and control group. In the control group measurements will also be performed at week 18, since these measurements are the "baseline data" of the one-year maintenance programme.
2. Improvement of OSAS defined by AHI and the other factors after 1 year maintenance programme (time interaction), for methods see primary outcome

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

Amended as of 09/06/2009:
The following points of the below inclusion criteria have been amended:
1. Patients with OSAS with an Apnoea-Hypopnea Index (AHI) greater than or equal to 15
3. Aged between 30 and 65 years
All other inclusion criteria remain unaffected.

Initial information at time of registration:
1. Patients with OSAS with an Apnoea-Hypopnea Index (AHI) between 15 and 60
2. Male patients
3. Age between 30 and 60 years
4. Abdominal obesity with a Body Mass Index (BMI) 30-40 kg/m^2 and waist circumference >102 cm
5. Signed informed consent to participate in the study

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Contraindications for VLCD:
1.1. Coronary thrombosis or myocardial infarct within the last three months
1.2. Cerebro-vascular accident within the last three months
1.3. Unstable ventricular arrhythmias
1.4. Major surgery or trauma within the last three months
1.5. Impaired renal or hepatic function
1.6. Severe depression
1.7. Use of mono-amine oxidase inhibitors (MAOIs)as anti-depressants
1.8. Anorexia nervosa or bulimia nervosa
1.9. Porphyria
1.10. Milk protein allergy (the diet is milk based)
1.11. Severe lactose intolerance (the diet is milk based)
1.12. (Pregnant and lactating women, children below the age of 14)
2. Drug treated diabetes
3. Currently on a weight loss drug (Acomplia®, Reductil® or Xenical®)
4. Bariatric surgery
5. Recent angina pectoris or atrial fibrillation

Recruitment start date


Recruitment end date



Countries of recruitment


Trial participating centre

Obesity Unit, m73

Sponsor information


Cambridge Manufacturing Company Limited (UK)

Sponsor details

Stafford House
10 Brakey Road
NN17 5LU
United Kingdom

Sponsor type




Funder type


Funder name

Cambridge Manufacturing Company Limited (UK) - main funder

Alternative name(s)

Funding Body Type

Funding Body Subtype


Funder name

Novo Nordisk (Denmark)

Alternative name(s)

Funding Body Type

private sector organisation

Funding Body Subtype

For-profit companies (industry)



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

2009 results in

Publication citations

  1. Results

    Johansson K, Neovius M, Lagerros YT, Harlid R, Rössner S, Granath F, Hemmingsson E, Effect of a very low energy diet on moderate and severe obstructive sleep apnoea in obese men: a randomised controlled trial., BMJ, 2009, 339, b4609.

Additional files

Editorial Notes