Abstract
Purpose :
Previous epidemiological studies have reported significant geographical and gender disparities in the prevalence of Diabetic Retinopathy (DR) and vision-threatening diabetic retinopathy (VTDR). However, the drivers responsible for this heterogeneity are yet to conclusively determined. The two contiguous South Indian states, Tamil Nadu (TN) and Kerala (KL) possess similar geographical, genetic, and ethnolinguistic landscapes. Despite these similarities, the prevalence of several non-communicable diseases, including DR, has been reported to be significantly higher in KL compared to TN.
Methods :
Data were evaluated by accessing the electronic health records of individuals presenting to five tertiary eye care facilities across South India from 2015-2019. The primary outcome was the diagnosis of DR or VTDR. Plasma Interleukin-6 (IL-6) concentration was measured using a commercial immunoassay. The secondary data from the National Sample Survey Organization was analyzed to study the per capita consumption patterns. Multivariate regression, Propensity score matching, Inverse probability treatment weighting, and doubly robust estimation, were employed to study the factors influencing the prevalence of DR and VTDR.
Results :
A total of 922,158 patients were included in the analyses, among which there were 263,592 patients with Type II DM. After adjustment for individual confounders, Type II DM patients from KL were 2.05 times (adjusted hazard ratio, 2.056; 95% CI, 2.009 to 2.114; P < 0.01) and 2.27 times (adjusted hazard ratio, 2.272; 95% CI, 2.138 to 2.413; P < 0.01) more likely to be diagnosed with DR and VTDR respectively. Men were 1.6 (adjusted hazard ratio, 1.633; 95% CI, 1.508 to1.687; P < 0.01) and 1.84 (adjusted hazard ratio, 1.835; 95% CI, 1.752 to 1.922; P < 0.01) times more likely to be diagnosed with DR and VTDR respectively. Plasma IL-6 was significantly higher in patients with DR (2.44 vs 1.39 pg/ml), in men (2.27 vs 1.41 pg/ml), in patients from KL (2.23 vs 1.65 pg/ml), and in patients consuming a coconut oil-rich diet (4.05 vs 2.29 pg/ml).
Conclusions :
The results of this study ascertain the existence of gender and geographical disparities in the prevalence of DR and suggest that elevated circulating levels of IL-6 could be a potential driving factor for both the gender and spatial heterogeneity in the prevalence of DR.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.