Cross-Sectional Analysis of the Involvement of Interleukin-17A in Diabetic Retinopathy in Elderly Individuals with Type 2 Diabetes Mellitus

BACKGROUND: To investigate the correlation between serum interleukin-17A (IL-17A) levels and diabetic retinopathy (DR) in elderly individuals with type 2 diabetes mellitus (T2DM). METHODS: The study included 194 elderly patients (94 males and 100 females) with T2DM. Digital retinal photography as well as fundus fluorescein angiography was employed to distinguish between nonproliferative diabetic retinopathy (NPDR) and proliferative diabetic retinopathy (PDR). In addition, multiple logistic regression analysis was conducted to determine the correlation between serum IL-17A levels and DR status. RESULTS: The average age of the study cohort was 69.14 ± 6.33 years, of which 52.08% were male. The study participants with the highest IL-17A (Q4) levels had higher TC, DBP, and low-density lipoprotein cholesterol (LDL-C) values than those the other groups. Analysis using unadjusted and adjusted linear regression revealed that the effect size of 1.09 for DR in the unadjusted model indicates that IL-17A is associated with an increase of 1.09 in DR (mmol/L) (β 1.09, 95% confidence interval (CI) 1.03, 1.16). Using the minimum-adjusted model (the model 2), as IL-17A increased, DR was higher by 1.11 (β 1.11, 95% CI 1.04, 1.18). With the fully adjusted model (the model 3), for each additional IL-17A increase, DR was higher by 1.15 (β 1.15, 95% CI 1.06, 1.24). CONCLUSION: Serum IL-17A levels are apparently positively correlated to DR in Chinese elderly individuals with T2DM.