In recent years, few medical developments have drawn as much public attention as GLP-1 medicines for obesity, moving quickly from specialist clinical conversations to everyday discussion. The evidence is evolving rapidly in response to demand from people living with obesity and decision-makers, who urgently need reliable information on which to base public health policy.
I’m a Consultant Systematic Reviewer at Covidence and part of my job is to help researchers configure Covidence to the needs of their review. To find out more about the current evidence on GLP-1 and to learn how Covidence is being used by teams around the world to produce this important information, I spoke with two Covidence users who are leading work in this area.
What are GLP-1 medicines?
Glucagon-like peptide-1 (GLP-1) receptor agonists were initially created to treat diabetes. They work by imitating the GLP-1 hormone, which helps regulate appetite and promotes a feeling of fullness. More recently they have also been used to manage obesity, a growing global health challenge and chronic complex disease impacting more than 1 billion people and contributing to millions of preventable deaths every year according to the World Health Organization.
What is the evidence on GLP-1 medicines?
Emerging evidence shows that GLP-1 medicines can help people with obesity lose a meaningful amount of weight, but important uncertainties remain. Three new Cochrane reviews, commissioned by the World Health Organization to inform guidance on the use of GLP-1 treatments in adults, found clear benefits for weight loss. The reviews also highlight the need for independent, long-term research to better understand how these medicines should be used in long-term weight management and policy decisions.
“We hope these Cochrane reviews will support high-quality, trustworthy decision-making on the use of GLP-1 interventions for people living with obesity,” said Dr Javier Bracchiglione, one of the lead reviewers on the three Cochrane reviews.
“The reviews were conducted with a very meticulous and rigorous approach, fully adhering to Cochrane methodological standards and explicitly incorporating the perspectives of the guideline panel—for example, when prioritizing outcomes and defining minimally important differences. This work directly informed the development of the WHO guideline, and we also undertook a detailed assessment of conflicts of interest in the included primary studies.”
Javier anticipates this work will have broader impact: “We expect these reviews to be useful for a wide range of decision-making processes, including clinical guideline development and health technology assessments at local, regional, national, and international levels.”
What about long-term efficacy?
While GLP-1 medicines can lead to significant weight loss, many people regain weight once they stop taking them. Another recent review and meta-analysis by a team of researchers from the University of Oxford looked at GLP-1 medicines and found that stopping use is often followed by rapid weight regain and a reversal of improvements in cardiometabolic health. These findings highlight the need for ongoing support, long-term treatment plans, and a strong focus on prevention in addition to short-term medicines in supporting people with obesity who are pursuing weight reduction.
Use of Covidence by the review teams
Covidence helps teams to build efficiency and transparency into their workflows and was used in this research at multiple stages in the review process. Sam West, lead author of the University of Oxford study, explained:
“My team used Covidence to screen titles and abstracts, review full texts and help inform our data extraction process. It helped us to keep track of the workflow. One of the challenges when you have so many papers to screen is keeping a track of who in the team has screened each paper, so that work is completed efficiently and conflicts can be resolved with ease. This was easy to manage in Covidence and the conflicts could be resolved with clear communication.”
Future research priorities
So, what should GLP-1 research focus on next?
Sam highlighted maintaining weight loss: “There are lots of questions to address going forward in this field, but one thing that is clear from our review is that we need to establish how we can best support people to maintain the weight loss either with continued treatment or post-treatment support.”
Javier called for research into adverse events: “There is still uncertainty about the long-term effects of GLP-1 analogues, particularly regarding adverse events and potential weight regain after discontinuation. This remains a critical issue that should be investigated in the near future.”
Accurate analyses
At Covidence we are committed to continuously enhancing our product tools to improve accuracy, efficiency, and usability for review teams. Through dedicated support and training services, Covidence helps researchers produce reliable, high-quality analyses.
To learn more about Covidence, visit www.covidence.org, where you can start your review journey for free and invite collaborators to join you. Covidence enables teams to collaborate seamlessly and produce high-quality evidence faster.
