Association of altered fibrinogen indexes levels as a potential biomarker in determining the possible onset of diabetic retinopathy.

Research suggests that fibrinogen was related to diabetic retinopathy (DR). Then, the relationship between functional indices of fibrinogen and detailed staging of DR has not been explored. Type 2 diabetic and healthy control subjects (n = 960) were recruited in a cross-sectional study. Participants with type 2 diabetes mellitus were categorized into five stages according to their fundus lesions, and fibrinogen (Fib) and its functional indices (angle α and k value) were measured. The angle α levels increased in diabetic subjects with retinopathy compared with those without, and it was significantly elevated early in retinopathy. In contrast, the k value levels slightly decreased. Despite observing an increase in angle α levels and a decrease in k value levels during the later stages of retinopathy compared to the earlier stages, there was no statistically significant difference in the later stages. The association of the angle α and k value with DR was independent of the hyperglycaemic state and other potential confounders (OR = 1.672, 95% CI 1.489-1.876, P < 0.01; OR = 0.013, 95% CI 0.004-0.041, P < 0.01). The angle α levels and k value levels were closely correlated with retinopathy (r = 0.593, P < 0.00; r = - 0.646, P < 0.01). The ROC curve indicated that the diagnostic value of angle α and k value were (AUC = 0.897, P < 0.001; AUC = 0.859, P < 0.001). Fibrinogen function indexes, such as angle α and k value, may be valuable for the early diagnosis of DR but do not directly assess the severity of DR.