A meta-analysis has revealed how GLP1 agonists provide a similar degree of glycaemic control to that achieved following bariatric surgery
Glucagon-like peptide-1 (GLP1) receptor agonists provide the same degree of glycaemic control as that achieved following bariatric surgery but the latter still confers the highest reductions in weight according to a systematic review and meta-analysis by researchers from Ontario, Canada.
According to the World Health Organisation, more than 1 billion people worldwide are obese and the organisation has estimated that by 2025, approximately 167 million people – adults and children – will become less healthy because they are overweight or obese. One particular disease linked to obesity is type 2 diabetes.
Moreover, lifestyle interventions such as a decreased caloric intake and increased physical activity in patients with type 2 diabetes, has been shown to result in a weight loss of 8.6%. An alternative approach to lifestyle modification, in those with type 2 diabetes is bariatric surgery, with 5-year outcome data showing that when combined with medical therapy, surgery was more effective than intensive medical therapy alone at decreasing, or in some cases resolving, hyperglycaemia. GLP1 agonists such as semaglutide have been shown to provide a sustained and clinically relevant reduction in body weight.
Nevertheless, there is a lack of evidence directly comparing GLP1 agonists with bariatric surgery in terms of weight loss and glycaemic control. Consequently, for the present study, the Canadian researchers undertook a systematic review and meta-analysis to directly compare the weight-lowering and glycaemic effect of GLP1 agonists and bariatric surgery in adults with obesity, defined as body mass index (BMI) > 25 kg/m2 in both randomised trial and observational cohort studies.
The primary outcome was the absolute change in weight from baseline to the end of the study period, whereas secondary outcomes were absolute change in body mass index and glycated haemoglobin (HbA1c) in patients with concurrent type 2 diabetes.
GLP1 agonists weight loss and glycaemic control outcomes
A total of 6 studies, both randomised trials and observational studies, with 332 participants were included in the final analysis.
The pooled treatment effect for the change in weight from baseline between bariatric surgery and GLP1 agonists was −22.68 kg (95% CI −31.41 to −13.96) in randomised trials and −25.11 kg (95% CI −40.61 to −9.60) among the observational studies and in both types of study, these results favoured bariatric surgery.
In terms of body mass index, as with overall weight, there was a higher effect from bariatric surgery compared with the GLP1 agonists across all studies. However, the change in glycaemic control (based on HbA1c) levels, based only on randomise trial evidence (due to missing data with the observational studies), was a nonsignificant difference of −1.28% (95% CI −1.94% to −0.61%).
This finding, the authors suggested, indicated that the improvement in glycaemic control achieved from GLP1 agonists may be comparable with metabolic surgery for patients with type 2 diabetes and obesity.
They concluded that among adults with obesity, bariatric surgery, while still providing the greatest level of weight loss conferred similar effects on glycaemic control to GLP1 agonists.
Sarma S et al. Weight loss between glucagon-like peptide-1 receptor agonists and bariatric surgery in adults with obesity: A systematic review and meta-analysis. Obesity (Silver Spring) 2022.