The Effects of Oxytocin in Obese Adults

A Randomized, Double-blind, Placebo-controlled Study to Evaluate the Effects of Repeat Doses of Intranasal Oxytocin in Obese Adults

This is a randomized, double blind, placebo-controlled study of the effects of intranasal oxytocin in obese adults, ages 18-45 years old. Subjects will be randomized to receive of intranasal oxytocin or placebo (3 sprays per nostril, 4 times per day) for 8 weeks. Study visits include screening to determine eligibility, a 2-part baseline visit, and visits every 2 weeks thereafter until week 14, with a safety follow-up visit 6 weeks after the last dose of study drug. Study procedures include behavioral, metabolic, neuroimaging, and endocrine assessments.

Study Overview

• Status: Completed
• Conditions: Obesity
• Intervention / Treatment: Drug: Placebo; Drug: oxytocin nasal spray

• Study Type: Interventional
• Enrollment (Actual): 61
• Phase: Phase 2

Contacts and Locations

Study Locations

• United States
  • Massachusetts
    • Boston, Massachusetts, United States, 02114
      • Massachusetts General Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years to 43 years (Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• 18-45 years old;
• BMI greater than or equal to 30 kg/m2

Exclusion Criteria:

• Use of drug affecting metabolism, glucose, or appetite (Metformin is allowed if dose and weight are stable for at least 3 months);
• history of medication changes within 4 weeks of enrollment;
• active substance use;
• history of cardiovascular disease, gastrointestinal disorders, bariatric surgery, epilepsy, untreated thyroid disease;
• hematocrit >2% below normal;
• fasting glucose > 125 mg/dL or hemoglobin A1c ≥ 7% ;
• ALT or AST >2.5 times upper limit of normal;
• Cr >1.5 mg/dL; hyponatremia;
• pregnancy or breastfeeding;
• unwilling to use medically acceptable form of contraception (females only)
• follows a nonstandard diet (e.g., gluten free, pescatarian, vegetarian, vegan, Paleo, Atkins, raw diet, macrobiotic diet)
• current smoking or tobacco use

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: oxytocin; oxytocin nasal spray (24 IU nasal spray, 4 times per day for 8 weeks)	Drug: oxytocin nasal spray; oxytocin intranasal spray; Other Names: Syntocinon
Placebo Comparator: placebo; placebo nasal spray (4 times per day for 8 weeks)	Drug: Placebo; Placebo nasal spray

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean Difference in Weight Loss Between Oxytocin and Placebo 8 Weeks After Baseline	The mean difference in weight loss between oxytocin- and placebo-treated groups from baseline to 8 weeks. All participants of the modified intention-to-treat cohort were aggregated into a single linear mixed effects model with the factors Time (Baseline, Week 2, Week 4, Week 6, and Week 8) and Group (oxytocin/placebo) and the interaction Time*Group controlled for sex (male/female) and obesity class (class I, II, and III) to produce a single value (estimated mean difference) and 95% confidence interval for the difference between groups and a single value (estimated mean change) within each group.	Baseline to 8 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Resting Energy Expenditure After 8 Weeks of Oxytocin Versus Placebo	The mean difference in resting energy expenditure between oxytocin- and placebo-treated groups from baseline to 8 weeks. All participants of the modified intention-to-treat cohort were aggregated into a single linear mixed effects model with the factors Time (Baseline and Week 8) and Group (oxytocin/placebo) and the interaction Time*Group controlled for sex (male/female), obesity class (class I, II, and III), and lean mass to produce a single value (estimated mean difference) and 95% confidence interval for the difference between groups and a single value (estimated mean change) within each group. Reported are model estimates rounded to one decimal.	Baseline to 8 weeks
Change in Fat Depots After 8 Weeks of Oxytocin Versus Placebo	The mean difference in total fat mass between oxytocin- and placebo-treated groups from baseline to 8 weeks. All participants of the modified intention-to-treat cohort were aggregated into a single linear mixed effects model with the factors Time (Baseline and Week 8) and Group (oxytocin/placebo) and the interaction Time*Group controlled for sex (male/female) and obesity class (class I, II, and III) to produce a single value (estimated mean difference) and 95% confidence interval for the difference between groups and a single value (estimated mean change) within each group.	Baseline to 8 weeks
Difference in Caloric Intake After 6 Weeks of Oxytocin Versus Placebo	The mean difference in caloric intake between oxytocin- and placebo-treated groups from baseline to 6 weeks. All participants of the modified intention-to-treat cohort were aggregated into a single linear mixed effects model with the factors Time (Baseline and Week 6) and Group (oxytocin/placebo) and the interaction Time*Group controlled for sex (male/female) and obesity class (class I, II, and III) to produce a single value (estimated mean difference) and 95% confidence interval for the difference between groups and a single value (estimated mean change) within each group.	Baseline to 6 weeks

Collaborators and Investigators

• Sponsor: Massachusetts General Hospital
• Investigators: Principal Investigator: Elizabeth A Lawson, MD, Massachusetts General Hospital

Study record dates

Study Major Dates

• Study Start (Actual): July 1, 2017
• Primary Completion (Actual): May 20, 2022
• Study Completion (Actual): July 7, 2022

Study Registration Dates

• First Submitted: February 1, 2017
• First Submitted That Met QC Criteria: February 2, 2017
• First Posted (Estimated): February 3, 2017

Study Record Updates

• Last Update Posted (Actual): February 7, 2024
• Last Update Submitted That Met QC Criteria: January 12, 2024
• Last Verified: January 1, 2024

More Information

Terms related to this study

• Keywords: magnetic resonance imaging; body mass index; oxytocin; weight loss
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Reproductive Control Agents; Oxytocics; Oxytocin
• Other Study ID Numbers: 2016P002810

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No