Abstract
Abstract: :
Purpose: To examine factors associated with diabetic retinopathy (DR) in different ethnic/racial groups at a diabetic clinic. Methods: A case series with case control analysis was performed on 1517 patients (2446 eyes). Cases had DR, controls had diabetes mellitus (DM) but no retinopathy. DR was documented with mydriatic 600 fundus color photographs read independently by two experienced ophthalmologists using modified Airlie House scoring. Three levels of DR were defined: none (level 10), mild/moderate (level 20 and 30), severe DR (level ≥35). The highest score by either ophthalmologist was the reference standard. Data included: age, sex, race, age of onset of DM, duration of DM, insulin use, smoking history, diagnosis of hypertension, systolic and diastolic blood pressure (BP), blood glucose, haemoglobin A1C (HbA1c), serum creatinine, cholesterol, triglyceride, and urinary albumin: creatinine ratio (ACR). The data were analysed using Stata, version 8, Stata corp. Results: The overall prevalence of DR was 26.5% and severe DR was 12.6%. Africans had significantly less DR (20.1%) compared with Whites (30.7%, p=0.0000) and Indians (28.3%, p=0.0193). The proportion of severe DR in patients who had DR was 58.6% in the African patients, significantly more than Whites (p=0.0106) in whom 42.3% of DR was severe. African patients had a shorter duration of DM (4.2 years) than Whites (9.6 years, p=0.0000), and Indians (7.5 years, p=0.0000). HbA1c of Africans was higher (10.4%) than Whites (9.3%, p=0.0000) and Indians (9.4%, p=0.0029). Significant associations with DR were: In 118 African patients: older age (p=0.0000), longer duration of DM (p=0.0000), hypertension (p=0.000), systolic BP (p=0.0006), urinary ACR (p=0058), creatinine (p=0.0050), cholesterol (p=0.0000). In 51 Indian patients: older age (p=0.0007), longer duration of DM (p=0.0002), hypertension (p=0.014), systolic BP (p=0.0243), urinary ACR (p=0.0079). In 227 White patients: longer duration of DM (p=0.0000), younger age at diagnosis of DM (p = 0.0000), insulin treatment (p = 0.000), hypertension (p=0.001), systolic BP (p=0.0000), diastolic BP (p=0.0067), urinary ACR (p=0.0009), creatinine (p=0.0060), cholesterol (p=0.0002). Conclusions: African patients showed poorer diabetic control and shorter duration of DM but with proportionately more severe DR than White and Indian patients. This may represent an accelerated course for DR in African patients related to their poor control of diabetes and other risk factors.
Keywords: diabetic retinopathy • clinical (human) or epidemiologic studies: risk factor assessment • clinical (human) or epidemiologic studies: prevalence/incidence