Association of C-reactive Protein with Diabetic Retinopathy in Young People with Type-I Diabetes Mellitus

Author(s): Rahman RJ, Zabeen B, Khaled MZ, Hassan SN, Rahman AKMS

Background: Diabetic retinopathy (DR) is a chronic, progressive sight threatening disease of the retinal microvasculature and is a significant complication of diabetes mellitus (DM). Type l diabetes mellitus (T1DM) is one of the most common metabolic conditions in childhood and adolescence. C-reactive protein (CRP) plays a major role in the human innate immune response and serves as a stable plasma biomarker indicating the presence of low-grade systemic inflammation.

Objective: This study aimed to assess the association of C-reactive protein (CRP) with diabetic retinopathy in young people with T1DM.

Methods: A total of 60 T1DM patients were included; of them 30 T1DM patients with retinopathy (cases- Group I) and 30 patients of T1DM without retinopathy (controls- Group II), aged between 10 to 24 years. Complete clinical evaluation including history, physical examination, relevant ocular examinations like visual acuity test, slit lamp examination, fundus examination both direct and indirect ophthalmoscopy and color fundus photography were done accordingly. Serum high sensitivity CRP (hs-CRP) level was measured following standard procedure.

Results: It was observed that, mean hs-CRP was significantly increased in retinopathy group compare to without retinopathy group (5.08±1.29 mg/L versus 3.43±0.69 mg/L, p<0.001). Mean hs-CRP level had significant difference among National Screening Committee (NSC) grading of retinopathy (p<0.001). Mean hs-CRP level was gradually increased with NSC grades. An age-adjusted and sex-adjusted model revealed that patients with highest hs-CRP (>4 mg/L) were 13.1 times more likely to have DR. Serum hs-CRP had a significant strong positive correlation with HbA1c in Group I (r=+.831, p<0.001) and Group II (r=.666, p<0.001). Patients with retinopathy group had significantly higher duration of DM and HbA1c compare to without retinopathy group (p<0.05), but this relation was lost in multivariate logistic regression model.

Conclusion: C-reactive protein (CRP) is strongly associated with diabetic retinopathy. Serum CRP also significantly related to different grades of retinopathy.