Long-term effects of bariatric surgery.

Rationale:

Bariatric surgery is the only effective way to induce sustained weight loss and reversal of the obesity-induced changes in lipid and glucose metabolism. Insight into the mechanisms underlying these highly desirable effects is crucial in the development of future treatment modalities for metabolic syndrome that do not involve the risks associated with surgery. Furthermore, gaining insight into the association between obesity and reduced striatal dopamine D2/3 receptor availability may provide valuable insight into the development of obesity and the metabolic syndrome and aid in the development of future treatment modalities.



Objective:

To determine whether the reduced striatal dopamine D2/3 receptor availability in morbidly obese women is reversed by long term weight loss after bariatric surgery. In addition, behavioral parameters and regulating factors involved in appetite regulation and glucose homeostasis will be studied and compared to data obtained prior to surgery and 6 weeks after surgery in an earlier study with the same participants. These regulatory factors will be correlated to changes in striatal D2/3R availability.



Study design:

Observational (follow-up) study.



Study population:

19 pre-menopausal Caucasian women that previously participated in our study "The pleiotropic metabolic effects of bariatric surgery" and underwent Roux-en-Y gastric bypass surgery at least 1 year ago.



Main study parameters/endpoints:

1. Changes in striatal D2/D3 receptor availability more than 1 year after bariatric surgery in a weight stable phase as compared to pre-operative measurements;

2. Comparison of glucoregulatory hormones as well as regulating hormones and metabolites involved in appetite regulation, before versus 1 year after surgery, and in relation to changes in striatal D2/3 R availability;

3. Behavioral changes, before versus at least 1 year after bariatric surgery in a weight stable phase.



Nature and extent of the burden and risks associated with participation, benefit and group relatedness:

Subjects will visit the research centre once. The amount of blood withdrawn does not expose the participant to any medical risk. The exposure to radiation during SPECT scans is considered to be intermediate. The same questionnaires and behavioural tasks were performed by the subjects in the previous study and are not expected to cause any psychological discomfort.

N/A

This follow-up study will take place at one time point. The acquired data will be compared to the data acquired in the same patients in our previous study 'The pleiotropic effects of bariatric surgery’ (MEC 08/161).

N/A