I read with great interest the article by Wong et al. (1) that was recently published in Diabetes Care. While the study provides valuable insights into the effectiveness of glucagon-like peptide 1 receptor agonists (GLP-1 RAs) for weight management, two critical issues warrant further attention.
First, publication bias is a significant threat to the validity of any meta-analysis. It is concerning that the authors did not describe any methods to assess publication bias in the statistical analysis section, and they did not address this issue in the discussion section. Given the high heterogeneity observed in the overall meta-analyses and most subgroup analyses presented in Tables 1–3, assessing publication bias would have provided valuable context for interpreting these results. Furthermore, the omission of a publication bias analysis is at odds with the authors’ claim that the meta-analysis adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, as outlined in the section on search strategy and selection criteria. This oversight undermines the transparency of the analysis and potentially influences the study’s conclusions.
Second, the study did not evaluate or discuss the potential effect of GLP-1 RAs on thyroid function. Animal studies have indicated that GLP-1 RAs may trigger abnormal transformations in thyroid C cells, eventually resulting in the formation of hyperplasia and adenomas (2). Furthermore, some clinical studies have shown that the administration of GLP-1 RAs can be associated with alterations in thyroid hormone levels or changes in thyroid function parameters, including thyroid-stimulating hormone levels (3). These findings raise significant concerns regarding the possible thyroid-related adverse effects associated with the use of GLP-1 RAs in patients with obesity or overweight. The authors included 47 randomized controlled trials, a considerable number, in their meta-analyses. It would be helpful if the authors could address this issue or provide a more in-depth discussion in this area.
In conclusion, addressing these two important issues would enhance the robustness and comprehensiveness of the study. Future research should incorporate an assessment of publication bias and investigate the potential impact of GLP-1 RAs on thyroid function to provide a more comprehensive understanding of their clinical implications.
Article Information
Acknowledgments. During the course of preparing this work, the author used ChatGPT for the purpose of spelling and grammar checking. Following the use of this tool, the author formally reviewed the content for its accuracy and edited it as necessary. The author takes full responsibility for all the content of this publication.
Duality of Interest. No potential conflicts of interest relevant to this article were reported.
Handling Editors. The journal editor responsible for overseeing the review of the manuscript was Frank B. Hu.
