Liraglutide and the management of overweight and obesity in people with schizophrenia, schizoaffective disorder and first-episode psychosis: protocol for a pilot trial

Background People with severe mental illness (SMI) are two to three times more likely to be overweight and obese than the general population and this is associated with significant morbidity and premature mortality. Although lifestyle interventions can support people with SMI to lose weight, some are unable to make the necessary lifestyle changes or, despite making the changes, continue to gain weight. Objective To assess the feasibility and acceptability of delivering a full-scale trial evaluating whether liraglutide 3.0 mg, a once-daily injectable therapy, may be an effective treatment of overweight and obesity in people with schizophrenia, schizoaffective disorder and first-episode psychosis. Methods Design: a single-centre, double-blind, randomised, placebo-controlled trial. Setting: mental health facilities within Southern Health NHS Trust. Participants: 60 adults with schizophrenia, schizoaffective or first-episode psychosis prescribed antipsychotic medication will be recruited. Participants will be overweight or obese, defined by their baseline BMI which will be: • BMI ≥ 30 kg/m2 or • BMI ≥ 27 kg/m2 to < 30 kg/m2 in the presence of at least one weight-related consequence. This is in concordance with the current EU licence for liraglutide (maximum dosage 3.0 mg). Intervention: participants will be allocated in a 1:1 ratio using a computer-based randomisation programme to either once-daily subcutaneously administered liraglutide or placebo, titrated to 3.0 mg daily, for 6 months. All participants will receive standardised written information about healthy eating and exercise at their randomisation visit. Outcomes: the main aim of the study is to gather data on recruitment, consent, retention and adherence. Qualitative interviews with a purposive sub-sample of participants and healthcare workers will provide data on intervention feasibility and acceptability. Secondary clinical outcome measurements will be assessed at 3 and 6 months and will include: weight, fasting plasma glucose, lipid profile, HbA1c level; and the Brief Psychiatric Rating Scale. Discussion This study should provide evidence of the potential benefits of liraglutide (maximum dosage 3.0 mg daily) on body weight and metabolic variables in people with schizophrenia, schizoaffective disorder and first-episode psychosis. It will also address the feasibility and acceptability of the use of liraglutide in mental health settings. This will inform the design of a longer outcome study that will be needed to determine whether any weight loss can be maintained in the long term.