The Role of Oxytocin-receptor Signalling in Physiological Regulation of Eating Behaviour in Individuals with Obesity

The Role of Oxytocin-receptor Signalling in Physiological Regulation of Eating Behaviour in Individuals with Obesity

The present study evaluates appetite, glucose metabolism, gastrointestinal motility and energy expenditure in men and women with obesity (BMI 30-40 kg/m2) under oxytocin exposure compared to placebo.

In a randomised, double-blind, placebo-controlled, crossover fashion, 24 participants will complete two experimental days (A and B) including a mixed meal test and an ad libitum meal test. The procedures during the two experimental days are similar except for intravenous infusion of oxytocin on experimental day A and placebo (saline) on experimental day B, respectively. On experimental days, oxytocin or placebo infusion will be started at timepoint -60 minutes. At timepoint 0 minutes, participants will ingest a liquid mixed meal. After 190 minutes, participants are served an ad libitum meal followed by ad libitum snacks.

Inclusion Criteria:

• Age 18-65 years
• BMI between 30 and 40 kg/m2 (both included)
• Percentage body fat (BF%) ≥25 for men and ≥32 for women (assessed by bioelectrical impedance analysis)
• Informed oral and written consent

Exclusion Criteria:

• Anaemia (haemoglobin below normal range)
• Alanine aminotransferase (ALT) >2 times normal values
• History of hepatobiliary and/or gastrointestinal disorder(s)
• Kidney disease (serum creatinine above normal range and/or urine albumin-creatinine ratio (uACR) >30 mg/g confirmed by two measures)
• Previous gastric or intestinal resection, cholecystectomy and/or any major intra-abdominal surgery (including bariatric surgery)
• Previous pancreatic disease and/or neoplasia
• Regular tobacco smoking and/or use of other nicotine products
• Glycated haemoglobin (HbA1c) ≥48 and/or type 1 diabetes or type 2 diabetes requiring medical treatment
• Pituitary gland disorders
• Initiation of special diets, lifestyle changes and/or weight loss >5% of total body weight within three months prior to or during study period
• Pregnancy or breastfeeding
• Long QTc on electrocardiogram (ECG) at screening (≥0.45 seconds for men and ≥0.46 seconds for women)
• Any physical or psychological condition or ongoing medication the investigator group suspect would interfere with trial participation