Obesity
Conditions
Brief summary
Adiposity is associated with prediabetes and type 2 diabetes. In very severe cases of adiposity in combination with type 2 diabetes, bariatric surgery has proven to be a successful therapy option. So far the molecular mechanisms that lead to an improvement of type 2 diabetes after bariatric surgery are not fully understood. It is planned to characterize the metabolic and neuroendocrine changes in subjects before and after bariatric surgery. One special focus of the study is brain insulin resistance, a condition known to be associated with obesity with impact on the brain and whole body metabolism.
Interventions
PROCEDUREBariatric surgery
laparoscopic Roux-en-Y gastric bypass or laparoscopic sleeve gastrectomy
Sponsors
University Hospital Tuebingen
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 75 Years
Healthy volunteers
No
Inclusion criteria
* age between 18 and 75 years * planned bariatric surgery (laparoscopic Roux-en-Y gastric bypass or laparoscopic sleeve gastrectomy) * stable medication 10 weeks before begin of the study
Exclusion criteria
* persons who wear non-removable metal parts in or on the body. * persons with reduced temperature sensitivity and / or increased sensitivity to heating of the body * cardiovascular disease can not be ruled out, e.g. manifest coronary heart disease, heart failure greater than NYHA 2, previous heart attack, stroke condition * persons with hearing impairment or increased sensitivity to loud noises * people with claustrophobia * minors or non-consenting subjects are also excluded * subjects with an operation less than 3 months * neurological and psychiatric disorders * subjects with hemoglobin Hb \<11 g / dl * hypersensitivity to any of the substances used
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Peripheral insulin sensitivity | Peripheral insulin sensitivity will be assessed by oral glucose tolerance as change before bariatric surgery and 6 months afterwards. | Peripheral insulin sensitivity will be assessed by oral glucose tolerance test. |
| Central insulin sensitivity | Central insulin sensitivity will be assessed as change before bariatric surgery and 6 months afterwards. | Central insulin sensitivity will be assessed by fMRI after application of nasal insulin or placebo. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Liver fat content | Liver fat content will be assessed by MRS prior bariatric surgery and 6 months afterwards. | Liver fat content will be assessed by MRS |
| Metabolic rate | Metabolic rate will be assessed by indirect calorimetry prior bariatric surgery and 6 months afterwards. | Metabolic rate will be assessed by indirect calorimetry |
| Response to food cues | Change in response to food cues will be assessed before bariatric surgery and 6 months afterwards. | Food cues will be rated for palatability on a visual analogue scale |
| Trail-making test | Change in trail-making test will be assessed before bariatric surgery and 6 months afterwards. | Trail-making test will be performed |
| Glucose tolerance | Glucose tolerance will be assessed by 75g oral glucose tolerance test prior to bariatric surgery and 6 months afterwards. | Glucose tolerance will be assessed by 75g oral glucose tolerance test. |
| Insulin secretion | Insulin secretion will be assessed by insulin measurements during 75g oral glucose tolerance test prior to bariatric surgery and 6 months afterwards. | Insulin secretion will be assessed by insulin measurements during 75g oral glucose tolerance test. |
| Weight loss | Weight loss before and 6 months after surgery. | Body weight will be measured before and 6 months after surgery. |
| Hopkins-verbal learning test | Change in Hopkins-verbal learning test will be assessed before bariatric surgery and 6 months afterwards. | Hopkins-verbal learning test will be performed |
| Whole body fat distribution | Body fat distribution will be assessed by MRI prior bariatric surgery and 6 months afterwards. | Body fat distribution will be assessed by MRI |
Other
| Measure | Time frame | Description |
|---|---|---|
| Liver, adipose tissue and muscle specimens | At surgery | During surgery liver, subcutaneous and visceral adipose tissue and skeletal muscle will be collected. |
Countries
Germany
Outcome results
None listed