Obesity
Conditions
Brief summary
Metformin is known to increase 18F-FDG uptake in subjects using metformin in retrospective trials. In this study the researchers aim to investigate the influence of metformin (500 mg 1/day) on temperature in the colon, glucose uptake in the colon and energy expenditure in healthy lean (BMI \< 24kg/m2) or obese subjects (BMI\>28kg/m2). The investigators will measure 18F-FDG uptake in the colon, temperature in the colon, insulin sensitivity and energy expenditure before after using metformin.
Detailed description
Obesity and diabetes mellitus type 2 (DM2) are health problems with a tremendous impact. Many attempts have been made to combat obesity and DM2, however, a breakthrough therapy is still lacking. Obesity is the result of an imbalance between energy intake and energy expenditure. 18F-fluorodeoxy-d-glucose (18F-FDG) positron emission tomography computed tomography (PET-CT) pinpoint areas with high glucose turnover. Physiological 18F-FDG accumulation is frequently observed in the colon. Therefore, the colon might play an important role in increasing energy expenditure by consuming calories. However, the possibility of the colon as an energy dissipating tissue has not yet been explored. The colon could become an interesting new target of research to find a method to combat obesity. Metformin is one of the few drugs in the treatment of DM2 that is associated with moderate weight loss. Interestingly, patients using metformin show an increased 18F-FDG-uptake in the colon. Whether this higher uptake of glucose also cause an increase in core temperature and/or an increase in energy expenditure is not known. The cause for this increase in glucose uptake in the colon by metformin use is unknown. Also, it is unknown whether this increase in glucose uptake results in an increased energy expenditure and/or an increase in core body temperature. Objective: In this study the researchers aim to investigate the influence of metformin (500 mg 1/day) on temperature in the colon, glucose uptake in the colon and energy expenditure in healthy lean (BMI \< 24kg/m2) or obese subjects (BMI\>28kg/m2). The investigators will measure 18F-FDG uptake in the colon, temperature in the colon, insulin sensitivity and energy expenditure before after using metformin.
Interventions
DRUGMetformin
Metformin vs no metformin
Sponsors
Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA)
Study design
Allocation
NON_RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
DIAGNOSTIC
Masking
NONE
Eligibility
Sex/Gender
MALE
Age
50 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* Male * Caucasian origin * Subjects should be able and willing to give informed consent * \> 50 years old * BMI\< 24 kg/m2 or \> 28 kg/m2
Exclusion criteria
* Renal failure (GFR\< 60ml/min) * Liver insufficiency (AST or alanine aminotransferase 3 times upper value) * Chronic use of drugs or medication * Diabetes mellitus * Lactate acidosis or precoma diabeticum in medical history * Acute or chronic diseases such as: dehydration, severe infection, shock, heartfailure, pulmonary insufficiency, recent heart attack * Alcoholism
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 18F-FDG uptake | 1 week | Difference in 18F-FDG uptake as registered by 18F-FDG PET-CT before and after 7 days of daily metformin use. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Core temperature using a temperature pill | 48 hours | \- Difference in core body temperature before and after metformin |
| Correlation core temperature and 18F-FDG uptake | 1 week | \- Correlation between 18F-FDG uptake in the colon and core temperature |
| Energy expenditure (kcal/day) using ventilated hood | 30 minutes | \- Difference in energy expenditure before and after metformin use |
| Correlation between 18F-FDG uptake and energy expenditure | 1 week | \- Correlation between difference inenergy expenditure and 18F-FDG uptake in the colon |
Countries
Netherlands
Outcome results
None listed