Rates of obesity in patients with schizophrenia-spectrum disorder (SSD)s have reached epidemic proportions, with established contributing effects of antipsychotic (AP) medications. Among agents approved for chronic weight management, glucagon-like peptide-1 receptor agonists (GLP-1RA) are associated with reductions in cardiovascular mortality, with recent FDA approval for once weekly semaglutide for this indication. This study will investigate whether semaglutide is effective in reducing body weight in overweight or obese individuals with SSDs who are on APs and do not demonstrate adequate weight loss on metformin (the first line treatment for weight loss in SSDs).
People with SSDs die early of iatrogenic cardiometabolic disease. Clinically, metformin remains the first line agent to mitigate this risk. In real-world clinical practice, metformin is likely to remain the first line treatment for AP-induced weight gain (given low cost, efficacy, and safety data). However, metformin is only effective in \~20% of patients. Hence, there is a need for interventions for AP-induced weight gain non-responsive to metformin. GLP-1RAs might represent the next rational step as they have a good safety profile, advantages of weekly administration, and early efficacy evidence to support their use in SSD and comorbid obesity, with benefits on dysglycemia, and visceral adiposity. Semaglutide, recently approved for chronic weight loss is an attractive option given a similar adverse effect profile but superior metabolic efficacy compared to other GLP-1 agents. The observations supporting an association between metabolic perturbations and cognition, along with preliminary evidence for neuroprotective effects of GLP-1RAs, suggest that by modifying metabolic risk factors, the investigators may be able to target difficult-to-treat domains of the illness such as cognitive dysfunction. This study will examine the effect of semaglutide on: 1. Percentage change in body weight 2. Measures of glucose metabolism and cardiovascular risk factors 3. Psychopathology 4. Cognition 5. Lifestyle-based assessments
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
SINGLE
Enrollment
92
The semaglutide dose will start with 0.25 mg/week, and slowly increased every four weeks as tolerated up to a maximal dose of 2 mg/week
Placebo will be provided to participants
Centre for Addiction and Mental Health
Toronto, Ontario, Canada
Weight change
Percentage change in body weight (kg)
Time frame: 32 weeks
Body Mass Index (BMI)
A person's weight in kilograms divided by height in metres squared
Time frame: 32 weeks
Waist circumference
Measured in centimetres
Time frame: 32 weeks
Oral glucose tolerance test
A standard glucose drink (75g) is given orally, and bloodwork containing insulin (pmol/L) and glucose (mmol/L) levels are obtained both at baseline and 2 hours after the glucose drink. These measures will help indicate B cell function and whole body insulin sensitivity, allowing for the proportion of individuals converting to impaired glucose tolerance, prediabetes, or type 2 diabetes to be determined.
Time frame: 32 weeks
Visceral and hepatic adiposity
An abdominal surface coil on the MRI will be used for this body composition measure
Time frame: 32 weeks
Fasting lipid profile
Cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL) and triglyceride levels will be collected through bloodwork in mmol/L
Time frame: 32 weeks
Psychopathology - Brief Psychiatric Rating Scale (BPRS)
Structured scale used to measure psychiatric symptoms
Time frame: 32 weeks
Psychopathology - Calgary Depression Scale for Schizophrenia (CDSS)
Structured scale used to measure depression in schizophrenia
Time frame: 32 weeks
Psychopathology - Global Assessment of Functioning (GAF)
Structured scale used to rate the global functioning of patient
Time frame: 32 weeks
Psychopathology - Clinical Global Impression scale (CGI)
Structured scale used to rate the global impression of patient
Time frame: 32 weeks
Change in cognitive performance
Evaluated through a standard scale called the MATRICS Consensus Cognitive Battery (MCCB)
Time frame: 32 weeks
Lifestyle assessment - Assessment of Quality of life (AQoL)
A structured scale used to measure health-related quality of life
Time frame: 32 weeks
Lifestyle assessment - WHO Disability Assessment Schedule 2.0 (WHODAS 2.0)
A structured measure of health and disability
Time frame: 32 weeks
Lifestyle assessment - International Physical Activity Questionnaire (IPAQ)
A structured measure of physical activity practices
Time frame: 32 weeks
Lifestyle assessment - The Fagerstrom Test of Nicotine Dependence (FTND)
A structured scale used to measure the intensity of nicotine dependence related to cigarette smoking
Time frame: 32 weeks
Lifestyle assessment - Penn State Nicotine Dependence Index-Cigarette/Electronic Cigarette
A structured measure used to quantify the intensity of physical dependence across various nicotine products
Time frame: 32 weeks
Lifestyle assessment - Canadian Diet History Questionnaire II (C-DHQ II)
A structured, comprehensive questionnaire used to measure food frequency
Time frame: 32 weeks
Lifestyle assessment - Food Cravings Questionnaire (FCQ)
A structured item used to measure frequency and intensity of food cravings
Time frame: 32 weeks
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