Zhao ZY, Wu PF, Sun NZ. Letter to the Editor: Leptin hypomethylation - an early epigenetic marker of lean-type diabetes. World J Diabetes 2026; 17(7): 117113 [DOI: 10.4239/wjd.117113]
Corresponding Author of This Article
Nian-Zhe Sun, MD, PhD, National Clinical Research Center of Geriatric Disorders, Xiangya Hospital, Central South University, No. 87 Xiangya Road, Kaifu District, Changsha 410008, Hunan Province, China. sunnzh201921@sina.com
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Endocrinology & Metabolism
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letter
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Zhao ZY, Wu PF, Sun NZ. Letter to the Editor: Leptin hypomethylation - an early epigenetic marker of lean-type diabetes. World J Diabetes 2026; 17(7): 117113 [DOI: 10.4239/wjd.117113]
World J Diabetes. Jul 15, 2026; 17(7): 117113 Published online Jul 15, 2026. doi: 10.4239/wjd.117113
Letter to the Editor: Leptin hypomethylation - an early epigenetic marker of lean-type diabetes
Zhong-Yi Zhao, Pan-Feng Wu, Nian-Zhe Sun
Zhong-Yi Zhao, Pan-Feng Wu, Nian-Zhe Sun, National Clinical Research Center of Geriatric Disorders, Xiangya Hospital, Central South University, Changsha 410008, Hunan Province, China
Co-first authors: Zhong-Yi Zhao and Pan-Feng Wu.
Author contributions: Zhao ZY wrote the first draft, developed the main ideas, and led the revisions; Zhao ZY and Wu PF contributed equally to this work and are the co-first authors of this manuscript; Wu PF and Sun NZ provided critical feedback, improved the structure, and added key examples. All authors thoroughly reviewed and approved the final manuscript.
AI contribution statement: Only DeepL was used to revise the language, grammar and sentence order of the manuscript. No AI tools such as ChatGPT and Grammarly were adopted in the whole research and writing process. No part of the main text, including the Abstract, Introduction, Materials and Methods, Results, Discussion, and Conclusion, was generated by AI or any AI tool. All content of the manuscript is independently completed by the authors. Only AI tools for language polishing and translation were used; no AI tools were used for data analysis or writing assistance throughout the preparation of this manuscript. No AI tools were involved in the study design, data analysis, or interpretation of the research results in this work. No AI tools were used in this study.
Conflict-of-interest statement: All authors declare no relevant conflicts of interest relevant to this article.
Corresponding author: Nian-Zhe Sun, MD, PhD, National Clinical Research Center of Geriatric Disorders, Xiangya Hospital, Central South University, No. 87 Xiangya Road, Kaifu District, Changsha 410008, Hunan Province, China. sunnzh201921@sina.com
Received: December 5, 2025 Revised: January 6, 2026 Accepted: February 5, 2026 Published online: July 15, 2026 Processing time: 223 Days and 3.3 Hours
Abstract
We read with interest study by Sun et al published in the World Journal of Diabetes. Type 2 diabetes mellitus (T2DM), a metabolic syndrome characterized by insulin resistance and hyperglycemia, has long been considered closely associated with obesity, which is commonly defined as a body mass index (BMI) ≥ 25 kg/m2. However, a large number of patients with T2DM in the Chinese population do not meet the BMI criteria for obesity. Leptin (LEP), a hormone secreted by the adipose tissue, is also closely linked to obesity. Interestingly, several studies have demonstrated that LEP resistance and hyperleptinemia can coexist in patients with T2DM. To date, little attention has been paid to the epigenetic regulation of the LEP gene in Chinese patients with T2DM and low BMI. Therefore, in the present cross-sectional study focusing on LEP disorders in lean diabetes, we explored the relationships between epigenetic regulation of the LEP gene, progression of T2DM, and serum LEP levels.
Core Tip: Epigenetic dysregulation of the leptin (LEP) gene in lean Chinese patients with diabetes remains understudied. Sun et al conducted a cross-sectional study to investigate the associations between LEP promoter methylation and serum leptin concentrations in relation to diabetes progression in non-obese individuals [body mass index (BMI) < 24 kg/m²]. The results showed that in lean adult Chinese patients, methylation of the LEP promoter gradually decreased with advancing diabetes, demonstrating a significant inverse correlation with serum leptin levels. These findings imply that LEP promoter methylation may act as a potential biomarker for early risk stratification of diabetes and prediction of its severity in non-obese patients with diabetes.
