Background
Semaglutide, a glucagon-like peptide-1 agonist, originally studied as a treatment for type 2 diabetes at doses of 0.5mg or 1.0mg, demonstrated a modest weight loss effect(1). At 2.4mg once weekly, a mean 16.9% weight reduction was achieved in adults with obesity(2). With semaglutide not on the PBS for treatment of obesity and the higher dose unavailable in Australia, lower diabetes doses have been used for weight management in Australia. This study uses real world data to assess the effectiveness of semaglutide in people with obesity managed in an outpatient obesity service.
Methods
In an observational study we reviewed our database for patients on semaglutide between June 2020-March 2022. Patients were excluded if they had no follow-up weights, no clear start date or missing data. The primary end point was percentage weight change from commencement of semaglutide.
Results
Of the 91 patients included, the majority (n=50) were taking a weekly maintenance dose of 1.0mg with 24 patients <1mg and 7 patients >1mg (average dose 0.91mg/wk). At baseline, mean body weight 134.8kg±33.4, mean BMI 48.6kg/m2±11.0. There was a mean weight change of −2.94% (95% confidence interval [CI], −1.74 to −0.92) at 3 months, −4.25% (CI −4.89 to −2.15) at 6 months, −4.63% (CI −11.51 to −2.28) at 12 months and −4.93% (CI −37.21 to −8.00) at 18 months. Weight loss at 18 months (n=13) was <5% in 23%, 5-10% in 23% and >10% in 31% of patients.
Conclusions
In this observational study of semaglutide in people with obesity attending an outpatient obesity service, average %weight loss was small and only significant at 3 months. This was not unexpected given the lower doses of semaglutide compared to that in the obesity trials. Further evaluation of higher dose semaglutide is required to assess efficacy for weight management in the real-world setting.