The Association and Clinical Implication of Hematological Inflammation Biomarkers and CRP in Diabetic Retinopathy Patients

Objective: Diabetic retinopathy (DR) is a major complication of diabetes, arising from chronic hyperglycemia that damages retinal blood vessels and can lead to blindness. While inflammation is implicated, its role remains unclear. This study aimed to investigate the relationship between haematological inflammation markers and C-reactive protein (CRP) in DR patients. Methods: A total of 175 participants (aged 25–75 years; 82 males, 93 females) were enrolled. Group I included DR patients (n = 75; mean age 59.33 ± 6.35 years), Group II comprised diabetic patients without retinopathy (n = 50; mean age 53.92 ± 11.79 years), and Group III consisted of age- and sex-matched controls (n = 50; mean age 50.28 ± 11.96 years). Hematological parameters and CRP were measured and compared across groups. Findings: DR patients exhibited significantly higher neutrophil-to-lymphocyte ratio (NLR: 2.724 ± 0.93; p < 0.0001) compared with controls. Absolute neutrophil count (ANC), red cell distribution width (RDW-SD), mean platelet volume (MPV), platelet large cell ratio (P-LCR), and CRP levels were also elevated in DR patients. A positive correlation was observed between NLR and CRP. Novelty: Complete blood count (CBC) tests, which measure red blood cell, white blood cell, and platelet parameters, are routinely performed in all healthcare settings. NLR reflects an imbalance between pro-inflammatory neutrophils and protective lymphocytes, while elevated CRP indicates vascular inflammation, both contributing to retinal damage DR. This study investigates associations of CBC-derived inflammatory markers (RDW, ANC, ALC, NLR, MPV, PDW, P-LCR) and CRP with DR, and further explores their relationships with HbA1c and diabetes duration to support early detection and monitoring of inflammation in DR. Keywords: ANC; C-reactive protein; Diabetic Retinopathy; NLR; Type 2 Diabetes mellitus