Incidence of diabetic retinopathy in Bangladesh: a 15-year follow-up study

Abstract

Background: The aim of the present study was to estimate the incidence of diabetic retinopathy (DR) among type 2 diabetic (T2D) subjects in Bangladesh.

Methods: A random sample of 977 patients with T2D was recruited retrospectively in 2008 from newly diagnosed T2D patients who had attended the Bangladesh Institute of Research and Rehabilitation in Diabetes, Endocrine and Metabolic Disorder (BIRDEM) in 1993. Baseline information for the cohort was collected for 1993 from hospital records. The mean time until development of DR in newly diagnosed T2D patients was calculated using survival analysis. Cox's proportional hazards model was used to assess factors affecting the time until development of DR.

Results: The cumulative incidence of DR over the 15-year period was 50.6% (95% confidence interval [CI] 47.5%-53.8%). The incidence density (per 100 person-years) of DR was similar in the overall cohort (4.1; 95% CI 3.7-4.5) and in men (4.2; 95% CI 3.7-4.7) and women (4.1; 95% CI 3.6-4.6) separately. The mean time (in years) until development of DR in the cohort was 9.72 (95% CI 9.38-10.06), with similar times in men (9.8; 95% CI 9.3-10.3) and women (9.6; 95% CI 9.5-10.1) analyzed separately. Age, sex, hypertension, lipid profile, HbA1c, and serum creatinine were entered into the hazards model simultaneously. However, only age (hazard ratio [HR] 0.75; 95% CI 0.61-0.92) and HbA1c (HR 0.52; 95% CI 0.33-0.82) had a significant effect on the time until development of DR.

Conclusions: Glucose deregulation is the most important factor in the development of DR.