Asian Spine J Search

CLOSE


Asian Spine J > Volume 20(1); 2026 > Article
Abudayeh and Fishchenko: Letter to the editor: Inconsistencies in obesity criteria: implications for systematic reviews on endoscopic spine surgery
To the Editor,
We read with great interest the article by Liawrungrueang et al. [1], “Endoscopic spine surgery for obesity-related surgical challenges: a systematic review and meta-analysis of current evidence.” The author addressed an important and timely topic; however, we wish to raise a methodological concern regarding the definition of obesity applied in the included studies. In the eligibility criteria, the review restricted inclusion to studies enrolling patients with a body mass index (BMI) ≥30 kg/m2. This threshold follows the World Health Organization (WHO) global standard, where obesity is defined as BMI ≥30 kg/m2 and overweight as BMI ≥25 kg/m2 [2]. However, closer examination of the included literature reveals that not all primary studies adhered to this definition. Specifically, Wu et al. [3] classified obesity as BMI >28 kg/m2, while Yao et al. [4] used BMI >25 kg/m2 as the obesity threshold. These criteria reflect alternative population-specific definitions, particularly those used in Asian cohorts, where metabolic and cardiovascular risks are elevated at comparatively lower BMI values. The WHO Expert Consultation [5] recommended lower BMI cutoffs for Asian populations: overweight defined as BMI ≥23 kg/m2 and obesity as BMI ≥25 kg/m2. Likewise, the Japan Society for the Study of Obesity defines obesity as BMI ≥25 kg/m2 [6]. This discrepancy in operational definitions of obesity is not trivial. Meta-analytic conclusions may be influenced by heterogeneity in exposure classification, potentially conflating overweight and obese categories across populations. For spine surgery research, where body habitus significantly impacts perioperative risk, surgical difficulty, and recovery, clarity in the applied obesity definition is essential to ensure accurate pooling of data and valid interpretation of results. We commend the author for this valuable contribution and respectfully suggest that future systematic reviews in this domain explicitly address regional variations in obesity criteria. Doing so will enhance the methodological rigor and global applicability of conclusions regarding endoscopic spine surgery in patients with elevated BMI.

Notes

Conflict of Interest

No potential conflict of interest relevant to this article was reported.

Author Contributions

All the work for the preparation of this letter was done by all authors.

References

1. Liawrungrueang W, Cholamjiak W, Sarasombath P, et al. Endoscopic spine surgery for obesity-related surgical challenges: a systematic review and meta-analysis of current evidence. Asian Spine J 2025;19:292–310. https://doi.org/10.31616/asj.2024.0376
crossref pmid pmc
2. World Health Organization. Obesity and overweight [Internet]. Geneva: World Health Organization; 2020 [cited 2025 Sep 2]. Available from: https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight

3. Wu J, Zhang C, Lu K, Li C, Zhou Y. Percutaneous endoscopic lumbar reoperation for recurrent sciatica symptoms: a retrospective analysis of outcomes and prognostic factors in 94 patients. World Neurosurg 2018;109:e761–9. https://doi.org/10.1016/j.wneu.2017.10.077
crossref pmid
4. Yao Y, Liu H, Zhang H, et al. Risk factors for recurrent herniation after percutaneous endoscopic lumbar discectomy. World Neurosurg 2017;100:1–6. https://doi.org/10.1016/j.wneu.2016.12.089
crossref pmid
5. WHO Expert Consultation. Appropriate body-mass index for Asian populations and its implications for policy and intervention strategies. Lancet 2004;363:157–63. https://doi.org/10.1016/S0140-6736(03)15268-3
crossref pmid pmc
6. Kanazawa M, Yoshiike N, Osaka T, Numba Y, Zimmet P, Inoue S. Criteria and classification of obesity in Japan and Asia-Oceania. World Rev Nutr Diet 2005;94:1–12. https://doi.org/10.1159/000088200
crossref pmid pmc


ABOUT
ARTICLE CATEGORY

Browse all articles >

BROWSE ARTICLES
EDITORIAL POLICY
FOR CONTRIBUTORS
Editorial Office
Department of Orthopedic Surgery, Asan Medical Center, University of Ulsan College of Medicine
88, Olympic-ro 43-gil, Songpa-gu, Seoul 05505, Korea
Tel: +82-2-3010-3530    Fax: +82-2-3010-8555    E-mail: asianspinejournal@gmail.com                
Korean Society of Spine Surgery
82, Gumi-ro 173beon-gil, Bundang-gu, Seongnam-si, Gyeonggi-do, 13620, Korea
Tel: +82-31-966-3413    Fax: +82-2-831-3414    E-mail: office@spine.or.kr                

Copyright © 2026 by Korean Society of Spine Surgery.

Developed in M2PI

Close layer
prev next