Study wrapper · #182
Benefits and Harms of Pharmacologic Treatments in Adults With Overweight or Obesity: A Living Systematic Review and Network Meta-analysis for the American College of Physicians.
Editor's note
A living systematic review and network meta-analysis for the American College of Physicians, and one of the strongest evidence syntheses in this batch: 69 randomised controlled trials, 112,511 participants, with 37 trials at low risk of bias. Network meta-analysis lets researchers rank treatments partly through indirect comparison, useful when head-to-head trials are scarce, but indirect estimates carry more uncertainty than direct ones. Researchers reported that nearly all drugs beat placebo or lifestyle intervention for weight loss while causing more adverse-event discontinuations; that semaglutide probably reduced mortality and major cardiovascular events; and that semaglutide and tirzepatide produced the greatest weight loss in both pairwise and network analyses. Crucially, the authors flagged that evidence for mortality, cardiovascular events and serious adverse events was limited and direct head-to-head data sparse, so the weight-loss ranking is far more certain than the hard-outcome claims. Weight this as high-quality comparative evidence for weight change, and more cautiously for survival and cardiovascular benefit.
Plain-language abstract
This was a large, continuously updated review that pooled results from many trials to compare weight-loss drugs. Researchers gathered 69 randomised controlled trials involving 112,511 people with overweight or obesity, and used a technique (network meta-analysis) that compares treatments both directly and indirectly through their shared comparison with placebo or lifestyle changes. Thirty-seven of the trials were judged to have a low risk of bias. Almost every drug produced more weight loss than placebo or lifestyle changes alone, but also caused more people to stop treatment because of side effects. Semaglutide probably lowered the risk of death and of major heart events such as heart attack and stroke. Both semaglutide and tirzepatide produced the largest amounts of weight loss. The authors cautioned that the evidence for death, heart events and serious side effects was limited, and that few trials directly compared one drug against another. Their overall conclusion was that semaglutide and tirzepatide showed the most favourable results across the outcomes studied, with the weight-loss findings more certain than the survival and heart findings.