Serum uric acid concentration is associated with worsening in severity of diabetic retinopathy among type 2 diabetic patients in Taiwan--a 3-year prospective study.

Aims: To explore the role of serum uric acid (SUA) concentration in diabetic retinopathy (DR) for patients with type 2 diabetes mellitus (T2DM).

Methods: A 3-year prospective study in 749 patients with T2DM and without proliferative diabetic retinopathy (PDR) was conducted at a medical center. Baseline SUA concentration and parameters of glycemic control, blood pressure, kidney disease, and lipid profiles were analyzed to determine their contribution to DR.

Results: Fundus examination showed that 184 patients (24.6%) had non-proliferative retinopathy and 565 (75.4%) without DR at baseline. After 3 years, increase in the severity of DR was recognized in 103 patients (13.8%), including 81 patients with newly developed DR. Patients with increase in severity of DR positively associated with duration of DM (11.9 vs. 9.4 years, p = 0.001), HbA1c (7.6 vs. 7.2%, p = 0.001), albuminuria (45.5 vs. 31.0%, p = 0.006), and SUA (6.47 vs. 5.87 mg/dl, p<0.001) than did those without change in DR stage. Cox regression showed that patients with SUA in the 3rd (5.9-6.9 mg/dl) and 4th (≥ 7.0mg/dl) quartiles had hazard ratios for DR worsening of 2.57 and 3.66 (95% C.I. 1.30-5.08 and 1.92-7.00) when compared with patients with SUA in the 1st quartile (<4.9 mg/dl).

Conclusions: SUA concentration is associated with the increase in severity of DR over a 3-year period in patients with T2DM. Further study is required to define the exact role of SUA in DR.