Plain English Summary
Background and study aims
Obesity is a term used to describe somebody who is very overweight, with a lot of body fat. It's a common problem, estimated to affect around one in every four adults and around one in every five children aged 10 to 11 in the UK. People who are obese are at risk of a number of serious and potentially life-threatening conditions, such as high blood pressure. High blood pressure is dangerous because it can have no symptoms, and increases the risk of a heart attack or stroke. It can also cause permanent damage to vital organs, such as the kidney, eye, brain and heart. Normally, high blood pressure can be treated with medications but these medications don’t work very well in obese patients and we’re not sure why. Most information on blood vessel structure comes from blood vessels studied in a laboratory. Here, we are using a technique which allows us to view blood vessels in the patient directly. Eye (retinal) blood vessel analysis is a non-invasive way to measure the structure of small blood vessels in a patient. The aim of this study is to get a better understanding of the differences in small blood vessel structure between obese patients and lean patients.
Who can participate?
Adults with a BMI over 30 or lower than 25.
What does the study involve?
Participants have non-invasive tests to check how well their blood vessels are functioning. Two of these tests are eye tests. There is also a blood test.
What are the possible benefits and risks of participating?
There are no risks or benefits to participating in this study.
Where is the study run from?
Wellcome Trust Clinical Trials Facility, Central Manchester University Hospitals Trust (UK)
When is the study starting and how long is it expected to run for?
June 2015 to January 2017
Who is funding the study?
British Heart Foundation (UK)
Who is the main contact?
Dr A Greenstein (scientific)
Trial website
Additional identifiers
EudraCT number
ClinicalTrials.gov number
Protocol/serial number
V1; 13/4/14
Study information
Scientific title
Identification of cardiovascular changes in obesity using dynamic and static retinal vessel analysis
Acronym
Study hypothesis
Changes in retinal vessel function can be correlated with obesity, blood pressure, pulse wave velocity and blood metabolic markers.
Ethics approval
North West - Greater Manchester South Research Ethics Committee, 29/07/2015 ref: 15/NW/0548
Study design
Single site cohort observation
Primary study design
Observational
Secondary study design
Cohort study
Trial setting
Hospitals
Trial type
Screening
Patient information sheet
Not available in web format, please use contact details to request a participant information sheet.
Condition
Cardiovascular disease associated with obesity
Intervention
1. Blood sampling for measurement of glycated haemoglobin (HbA1C) and cholesterol
2. Imaging of the retinal vessels using a fundal camera to measure response to hypertension
3. Pulse wave velocity to measure perfusion and blood flow in the peripheral circulation
Intervention type
Other
Phase
Drug names
Primary outcome measures
Vascular function measured by degree of response to flicker stimulation, retinal arteriolar-venular ratio (AVR) and blood oxygen saturation.
Secondary outcome measures
Peripheral measurements: blood pressure, pulse wave velocity and blood levels of HbA1c and blood lipids (triglycerides, LDL and HDL cholesterol).
Overall trial start date
01/06/2015
Overall trial end date
31/01/2017
Reason abandoned
Eligibility
Participant inclusion criteria
Patient-participants:
1. Willing and capable to provide consent to participation
2. BMI greater than 30
3. No known ocular diseases
4. No known concurrent clinical problem likely to interfere with participation or completion of the study
Healthy controls:
1. BMI lower that 25
2. No known diabetes
3. No known ocular diseases
4. No known concurrent clinical problem likely to interfere with participation or completion of the study
Participant type
Mixed
Age group
Adult
Gender
Both
Target number of participants
30 healthy lean controls and 30 obese patient-participants
Participant exclusion criteria
1. Under 18 years old
2. Intubated/ventilated patients
3. Unwilling to give consent to participation OR advised by consultee that this would be against the patient’s wishes
4. Smoker
5. If eaten with in an hour of the examination
6. If drank alcohol within an hour of the examination
7. If drank coffee within an hour of the examination
8. If overly hungry
9. Recently treated infection
10. Known ocular diseases
11. Known concurrent clinical problem likely to interfere with participation or completion of the study
Additional exclusion for healthy controls:
1. Diabetes
2. BMI above 25
Recruitment start date
01/06/2015
Recruitment end date
31/01/2017
Locations
Countries of recruitment
United Kingdom
Trial participating centre
Wellcome Trust Clinical Trials Facility, Central Manchester University Hospitals Trust
Oxford Road
Manchester
M13 9WL
United Kingdom
Funders
Funder type
Charity
Funder name
British Heart Foundation
Alternative name(s)
Funding Body Type
Funding Body Subtype
Location
Results and Publications
Publication and dissemination plan
We hope to publish a paper in a peer reviewed journal by January 2017.
Intention to publish date
01/01/2017
Participant level data
Not provided at time of registration
Results - basic reporting
Publication summary