Obesity
Conditions
Keywords
obesity, adipose tissue lipolysis, lipolysis, microdialysis, atrial natriuretic peptide
Brief summary
In the developing countries, obesity prevalence is on a dramatic rise. Obesity is related to co-morbidities and as a result, obesity significantly shortens life expectancy and lowers quality of life. To prevent this, participation in exercise or training programs is absolutely necessary, in order to generate adipose tissue mass loss. The amount of adipose tissue mass loss is, amongst others, dependent on lipolysis which is under endocrine regulation by, mainly, catecholamines, insulin and atrial natriuretic peptide. However, large variations in adipose tissue mass loss and gain are likely in obese subjects, possibly due to a decreased lipolytic effect of these hormones (as was shown for catecholamines in the subcutaneous adipose tissue of obese subjects). However, the relative contribution of atrial natriuretic peptide in the lipolytic process remains elusive, particularly in subjects with obesity, which show an increased plasma expression of atrial natriuretic peptide. The aim of the present study is to observe the contribution of atrial natriuretic peptide in the subcutaneous adipose tissue of obese subjects. This will be tested by measurements of extracellular glycerol levels (by microdialysis) in the subcutaneous adipose tissue in situ at rest and during endurance exercise under local beta- and alpha-blockade. Eventually, the knowledge gained from this research will contribute to the optimization of exercise programs for people with obesity.
Interventions
OTHERsubcutaneous adipose tissue microdialysis under local beta/alpha blockade
adipose tissue lipolysis under local beta/alpha blockade in abdominal subcutaneous adipose tissue, using microdialysis
Sponsors
Jessa Hospital
Maastricht University
Hasselt University
Study design
Observational model
COHORT
Time perspective
RETROSPECTIVE
Eligibility
Sex/Gender
MALE
Age
35 Years to 60 Years
Healthy volunteers
Yes
Inclusion criteria
* Obese group: BMI \> 30 kg/m², sedentary (no regular physical activity last 6 months), insulin sensitive or insulin resistant * Lean controls: BMI \> 18.5 kg/m² and \< 25 kg/m², regular physical activity, insulin sensitive
Exclusion criteria
* Regular glucose lowering medication or beta blockade medication * Presence of chronical diseases * Orthopedic or neurological problems
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Atrial natriuretic peptide (ANP) Response | week 1 | measurement systemic ANP response (venous blood sampling) |
| Subcutaneous adipose tissue microdialysis | week 1 | abdominal subcutaneous adipose tissue microdialysis during rest and exercise; basal + under local alpha- and beta-blockade. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Maximal oxygen uptake (ml/O2/kg/min) | Day 1 | measured using indirect calorimetry and an incremental bicycle protocol |
| Central insulin sensitivity | screening | Fasting serum insulin, homeostasis model assessment insulin resistance and measures of central insulin sensitivity derived from an oral glucose tolerance test (75g) |
| Abdominal subcutaneous adipose tissue biopsy | week 1 | biochemical, proteomics and morphological analyses |
| Anthropometry | screening | body composition, measured using dual x-ray absorptiometry, height, weight, waist and hip circumference |
| Echocardiography | Day 1 | heart function by means of standard echocardiography |
Countries
Belgium
Outcome results
None listed