Background/aims Obesity is a well-known risk factor for diabetes, but its association with diabetic retinopathy (DR) is inconclusive, in particular in Asians. We aimed to assess whether body mass index (BMI) is associated with the presence and severity of DR in Asian populations with diabetes.
Methods Pooled analysis of individual-level cross-sectional data from 10 010 adults with diabetes who participated in 12 population-based studies conducted in China, India, Japan, Russia (Asian), Singapore and South Korea that were part of the Asian Eye Epidemiology Consortium (AEEC). BMI was calculated as weight in kilograms divided by height in square metres and categorised into normal (<25 kg/m2, reference), overweight (25–29.9 kg/m2) and obese (≥30 kg/m2). Any-DR (n=1669) and vision-threatening DR (VTDR, n=489) were assessed from digital retinal photographs and graded according to standard protocols. Each study was analysed separately using multivariable logistic regression models adjusted for age, sex, haemoglobin A1c%, systolic blood pressure and diabetes duration, and the estimated odds ratios (ORs) and 95% confidence interval (CIs) from all studies were then combined using random-effects models.
Results In multivariable models, obesity showed a significant inverse association with any-DR (pooled OR (95% CI) =0.74 (0.59 to 0.91)) and VTDR (0.75 (0.60 to 0.93)). Similarly, in continuous analysis, BMI showed a significant inverse association with both any-DR (0.93 (0.87 to 0.99)) and VTDR (0.79 (0.68 to 0.92) per SD increase). Overweight did not show a significant association with any-DR.
Conclusions Among Asian adults with diabetes, both BMI and obesity showed an inverse association with DR. These findings warrant confirmation in further longitudinal studies.
Statistics from Altmetric.com
Collaborators Se Woong Kang (Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Republic of Korea), Kyu Hyung Park (Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Republic of Korea), Govindasamy Kumaramanickavel (Aditya Jyot Foundation for Twinkling Little Eyes, Mumbai, India), Sundaram Natarajan (Aditya Jyot Foundation for Twinkling Little Eyes, Mumbai, India), Koh-Hei Sonoda (Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan), Gyulli M Kazakbaeva (Ufa Eye Research Institute, Ufa, Russia) and Janani Surya (Shri Bhagwan Mahavir Vitreoretinal Services, Sankara Nethralaya, Chennai, India).
Contributors All authors contributed to the intellectual development of this paper. CS and JBJ had the original idea for the study. CS designed the study, supervised data analysis and wrote the first draft. RS performed the analysis, assisted by MLC. RB performed the literature review. CS, RS, RB, TR, YCT, SM, MLC, YXW, VN, KF, EST, SJS, MMB, RR, CYC, TYW and JBJ assisted in interpretation of the analysed data and provided critical corrections of the manuscript. CS is the guarantor of this work and as such had full access to all the data in the study and takes responsibility for the integrity of the data and accuracy of the data analysis. Final version of the paper has been seen and approved by all the authors.
Funding This study was supported by the National Medical Research Council, NMRC/STaR/003/2008, NMRC/0796/2003 and NMRC/1249/2010.
Disclaimer The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests None declared.
Patient consent for publication Not required.
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement Data are available upon reasonable request. As the study involves human participants, the data cannot be made freely available in the manuscript, the supplemental files or a public repository due to ethical restrictions. Nevertheless, the data are available from the Singapore Eye Research Institutional Ethics Committee for researchers who meet the criteria for access to confidential data. Interested researchers can send data access requests to the Singapore Eye Research Institute using the following email address: email@example.com.
Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.