Association between light at night and diabetic retinopathy is modified by residential greenness: A nationwide study in China
Zilin Wang, Zhihan Zhang, Yunxuan Wei, Guanran Zhang, Xiaodong Sun, Ying Hu, Yanlin Qu, Huixun JiaAbstract
Background:
Light at night (LAN), which has become an inevitable byproduct of rapid urbanization, may be associated with diabetic retinopathy (DR). We aimed to investigate the association between LAN exposure and the risk of DR, and explore the potential protective modifying effect of greenness on the LAN–DR association.
Methods:
In this nationwide cross-sectional study, 521,093 participants with diabetes across 27 provinces and 1010 centers were included. DR was diagnosed and graded based on fundus images. LAN and greenness were quantified using satellite-based models. Multivariable logistic regression models were used to assess the association between LAN and DR. Stratified analyses were conducted across different levels of greenness to explore the modifying effect on the LAN–DR association.
Results:
A total of 84,710 (16.3%) participants had DR. Excessive LAN exposure was associated with a higher prevalence of DR and its related retinal lesions. Compared with participants in the lowest quartile, those in the highest quartile had 74%, 34%, and 104% higher odds of overall, moderate, and severe DR, respectively. Regardless of the additive or multiplicative scale, a protective modification effect of greenness on LAN-DR association was observed. Stratified analyses showed that the detrimental effect of LAN on DR and its related retinal lesions was significantly lower in those with high greenness exposure, even to be non-significant for macular edema (OR: 1.02; 95% CI: 0.97–1.06;
Conclusions:
This study provides an epidemiological evidence of a positive association between LAN exposure and the prevalence of DR, and suggests that greenness may be a protective factor attenuating the LAN–DR association. Our findings highlight the potential relevance of residential environmental factors in DR and underscore the need for further investigation into the role of greenness in modifying environmental health risks.