Associations of serum uric acid to eGFR ratio with diabetic retinopathy in individuals with type 2 diabetes.

Serum uric acid (SUA) is closely associated with diabetes and its complications. The relationship between SUA and diabetic retinopathy (DR) remains unclear, with conflicting results from current studies on SUA in DR Patients. Since uric acid is primarily excreted by the kidneys, the ratio of SUA to eGFR (SUA/eGFR) serves as a renal function-corrected indicator of SUA levels. We tested whether SUA/eGFR might be involved in the pathogenesis and progression of DR. We collected data from 1,399 patients with type 2 diabetes mellitus (T2DM) who were hospitalized between January 2023 and April 2024. They were divided into diabetes without DR (nondiabetic retinopathy, NDR) group (N = 438), non-proliferative diabetic retinopathy (NPDR) group (N = 902) and proliferative diabetic retinopathy (PDR) group (N = 59). Univariate and multivariate logistic regression analyses were used to analyze the relationship between SUA/eGFR and DR and its severity. The SUA/eGFR levels increased with the severity of DR (P<0.05). In the multinomial logistic regression model using patients without DR as the reference, SUA/eGFR was significantly linked with PDR (OR = 1.07, 95%CI 1.00-1.14; P = 0.036), while NPDR group showed no significant difference (P>0.05). In T2DM patients younger than 60 years, SUA/eGFR was positively associated with an increased risk of DR (OR = 1.20, 95%CI 1.05-1.38, P = 0.01). Among T2DM patients with HbA1c > 7%, higher SUA/eGFR levels were linked to a greater risk of DR(OR = 1.10, 95%CI 1.00-1.20, P = 0.045). Stratified analysis by age showed that in T2DM patients younger than 60 years, SUA/eGFR was positively correlated with the severity of DR (NPDR:OR = 1.20, 95%CI 1.04-1.38, P = 0.01; PDR: OR = 1.20, 95%CI 1.04-1.38, P = 0.012). Additionally, stratified analysis by HbA1c levels indicated that among T2DM patients with HbA1c > 7%, those with higher SUA/eGFR levels had an increased risk of DR severity (NPDR:OR = 1.09, 95%CI 1.00-1.19, P = 0.049; PDR: OR = 1.10, 95%CI 1.01-1.20, P = 0.037). Our study reported a positive association between SUA/eGFR and DR and its severity in younger T2DM patients with poorly controlled blood glucose levels. T2DM patients with higher SUA levels had an increased risk of more severe DR (progressing from NPDR to PDR). However, more prospective and high-quality clinical evidence is needed to confirm these current findings.