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Copyright ©The Author(s) 2025. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Diabetes. Sep 15, 2025; 16(9): 108480
Published online Sep 15, 2025. doi: 10.4239/wjd.v16.i9.108480
Income and wealth inequality is associated with young-onset type 2 diabetes
Fu-Shun Yen, James Cheng-Chung Wei, Yao-Min Hung, Jia-Sin Liu, Chii-Min Hwu, Chih-Cheng Hsu
Fu-Shun Yen, Dr. Yen’s Clinic, Taoyuan 330, Taiwan
James Cheng-Chung Wei, Department of Allergy, Immunology and Rheumatology, Chung Shan Medical University Hospital, Taichung 40201, Taiwan
James Cheng-Chung Wei, Graduate Institute of Integrated Medicine, China Medical University, Taichung 40201, Taiwan
James Cheng-Chung Wei, Institute of Medicine, Department of Nursing, Chung Shan Medical University, Taichung 40201, Taiwan
Yao-Min Hung, Department of Internal Medicine, Taitung Hospital, Taitung 95043, Taiwan
Jia-Sin Liu, National Health Research Institutes, Miaoli 35053, Taiwan
Chii-Min Hwu, Section of Endocrinology and Metabolism, Department of Medicine, Taipei Veterans General Hospital, Taipei 112, Taiwan
Chii-Min Hwu, Faculty of Medicine, National Yang Ming Chiao Tung University School of Medicine, Taipei 112, Taiwan
Chih-Cheng Hsu, National Center for Geriatrics and Welfare Research, Institute of Population Health Sciences, National Health Research Institutes, Miaoli 35053, Taiwan
Chih-Cheng Hsu, Department of Health Services Administration, China Medical University, Taichung 40201, Taiwan
Chih-Cheng Hsu, Department of Family Medicine, Min-Sheng General Hospital, Taoyuan 330, Taiwan
Co-corresponding authors: Chii-Min Hwu and Chih-Cheng Hsu.
Author contributions: Yen FS and Hsu CC conceived and designed the study, interpreted the data, discussed and interpreted the results, and wrote and revised the manuscript; Wei JCC, Hung YM, and Liu JS conceived and coordinated the study, collected and analyzed the data, discussed the results, and critically reviewed the manuscript; Hwu CM conceived the study, coordinated and supervised data collection, interpreted data, discussed and interpreted results, and revised and critically reviewed the manuscript; Hwu CM and Hsu CC played important and indispensable roles in the experimental design, data interpretation, and manuscript preparation as the co-corresponding authors; All authors approved the final manuscript as submitted and agreed to be accountable for all aspects of the work.
Supported by Taipei Veterans General Hospital, No. V113C-166 and No. V114C-177; and National Science and Technology Council, R.O.C, No. NSTC113-2314-B-075-007-.
Institutional review board statement: The National Health Research Institutes Institutional Review Board approved this study.
Informed consent statement: Informed consent was waived by the Institutional Review Board.
Conflict-of-interest statement: The authors have no conflicts of interest to declare.
STROBE statement: The authors have read the STROBE Statement—checklist of items, and the manuscript was prepared and revised according to the STROBE Statement—checklist of items.
Data sharing statement: Data of this study are available from the National Health Insurance Research Database (NHIRD) published by Taiwan National Health Insurance Administration. The data utilized in this study cannot be made available in the paper, the supplemental files, or in a public repository due to the ‘‘Personal Information Protection Act’’ executed by Taiwan government starting from 2012. Requests for data can be sent as a formal proposal to the NHIRD Office or by email to stsung@mohw.gov.tw.
Open Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Chii-Min Hwu, MD, Professor, Section of Endocrinology and Metabolism, Department of Medicine, Taipei Veterans General Hospital, No. 201 Shi-Pai Road, Section 2, Chung-Cheng Build, Taipei 112, Taiwan. chhwu@vghtpe.gov.tw
Received: April 17, 2025
Revised: June 3, 2025
Accepted: August 1, 2025
Published online: September 15, 2025
Processing time: 148 Days and 1 Hours
Abstract
BACKGROUND

There are only a few studies on the influence of economic inequalities on young-onset type 2 diabetes (T2D).

AIM

To examine the impact of different family incomes on the development of young-onset T2D.

METHODS

We identified 7505336 young adults aged 20-39 years from the 2008 Taiwan National Health Insurance Research Database. The young adults were divided into low-income, middle-income, and high-income groups. Cox proportional hazards models were used to determine the risks of young-onset T2D and all-cause mortality in low-income and middle-income groups compared with the high-income group.

RESULTS

With a mean follow-up of 8.0 years, the incidence rates of young-onset T2D were 3.39, 3.10, and 2.88 per 1000 person-years in the low-income, middle-income, and high-income groups, respectively. Compared with the high-income group, the risk of young-onset T2D was significantly higher in the low-income [adjusted hazard ratio (aHR) (95%CI): 1.46 (1.44–1.48)] and middle-income [aHR (95%CI): 1.29 (1.27–1.31)] groups. All-cause mortality was also higher in the low-income [aHR (95%CI): 2.79 (2.70–2.88)] and middle-income [aHR (95%CI): 1.59 (1.53–1.65)] groups. Older age, male sex, obesity, smoking, alcohol-related disorders, hypertension, dyslipidemia, gout, and psychotic disorders were significantly associated with increased risks of both young-onset T2D and mortality.

CONCLUSION

This nationwide cohort study demonstrated that young people from low-income and middle-income groups had a higher risk of youth-onset T2D and mortality than those from the high-income group.

Keywords: All-cause mortality; Family income; Young-onset type 2 diabetes; Young-onset diabetes; Low-income; Middle-income; High-income

Core Tip: This nationwide cohort study analyzed data from over 7.5 million Taiwanese adults aged 20-39 years to evaluate the impact of socioeconomic status on young-onset type 2 diabetes. Using Cox proportional hazards models, we found that individuals from low-income and middle-income families had a significantly higher risk of developing young-onset diabetes and all-cause mortality compared with those from high-income families. These findings highlight the critical role of poverty in early-onset type 2 diabetes development and mortality risk, emphasizing the need for targeted public health interventions in socioeconomically disadvantaged populations.