The objective of the study is to investigate the change in β2-AR-stimulated lipolysis with weight loss and its association with changes in adipose tissue hypoxia and/or oxidative stress.
ID
Source
Brief title
Condition
- Other condition
Synonym
Health condition
vetweefseldisfunctie bij obesitas
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
For the pre- and post-measurement a subcutaneous adipose tissue biopsy of about
1 gram will be taken. one part will be used to measure sensitivity to β2-AR
stimulation of lipolysis with salbutamol in adipocytes isolated from the
biopsy.
Secondary outcome
Another part of the adipose tissue biopsy will be used to measure markers of
local adipose tissue hypoxia and oxidative stress with western blot and PCR
techniques.
In addition a 5 ml venous blood sample and a small urine sample will be
collected at both occasions. Markers of systemic oxidative stress will be
measured in plasma and urine samples.
Background summary
Obesity is associated with impaired sensitivity of β2-adrenergic receptor (β2-
AR)-stimulated lipolysis. Impaired lipolysis may be one factor contributing to
maintenance of the obese state. Several studies have investigated the effects
of weight loss on β2-AR-stimulated lipolysis after weight stabilization. These
studies suggest that in vitro lipolytic sensitivity to β2-AR stimulation of
adipocytes increases after weight loss. Two possible mechanisms involved in β2-
AR-stimulated lipolysis in obesity are adipose tissue hypoxia and oxidative
stress. These factors have already been shown to be associated with obesity and
with β-adrenergic sensitivity, but it is not clear yet whether these factors
impair β2-AR-stimulated lipolysis in obese subjects. Our hypotheses are that
weight loss increases sensitivity to β2-AR-stimulated lipolysis and that this
goes together with decreases in adipose tissue hypoxia and/or oxidative stress.
Study objective
The objective of the study is to investigate the change in β2-AR-stimulated
lipolysis with weight loss and its association with changes in adipose tissue
hypoxia and/or oxidative stress.
Study design
This is a longitudinal study with one pre- and post-measurement. Subjects
participating in an obesity treatment programme will be measured before the
start of the programme and after 9 months participation. After 9 months in the
treatment programme, subjects have reached relatively stable body weight and
have on average lost 8.2% of their body weight .
Study burden and risks
This study has no direct benefits for the subjects but it sheds light on
whether weight loss is able to improve β2-AR-sensitivity and possible
mechanisms involved in decreased β2-AR-sensitivity in obesity. Two subcutaneous
abdominal adipose tissue biopsies, two blood samples and two urine samples will
be needed. The burdens from these procedures will be kept to a minimum.
universiteitssingel 50
6229 ER
NL
universiteitssingel 50
6229 ER
NL
Listed location countries
Age
Inclusion criteria
- All subjects entering the CO-Eur programme (life style intervention at the obesity treatment centre
CO-Eur in Heerlen). Co-Eur only includes subjects with age>18 years and BMI>30kg/m2
- No more than 3 kg weight change in the past 3 months
- age>18 years
Exclusion criteria
- Smoking
* Diabetes
* (Medicinal) use of β-blockers or β-agonists
* Pregnant women
- (medicinal) use of anticoagulantia or blood clotting problems
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL35932.068.11 |