Retinopathy in subjects with type 2 diabetes at a tertiary diabetes clinic in Durban, South Africa: Clinical, biochemical and genetic factors.

AIM

To determine the prevalence of clinical and laboratory variables and genetic polymorphisms in association with diabetic retinopathy (DR) in subjects with type 2 diabetes attending a tertiary referral diabetes clinic in Durban, South Africa.

METHODS

Cross-sectional study on 292 Indian and African patients with type 2 diabetes (71.5% women). The presence of DR was determined by direct ophthalmoscopy. Clinical and laboratory data were collected and polymorphisms in the (rs61722009, rs2070744, rs1799983) and (rs35569394, rs2010963) genes were determined.

RESULTS

DR was present in 113 (39%) subjects. Those with DR were older (60.6 ± 9.6 vs. 55.4 ± 12.9 years,  = 0.005), had longer duration diabetes (18.5 ± 8.8 vs. 11.9 ± 9.2 years,  < 0.0001), higher HbA (9.2 ± 1.8 vs. 8.8 ± 1.7%,  = 0.049), serum creatinine (106.3 ± 90.2 vs. 75.2 ± 33.4 μmol/l), triglycerides (2.1 ± 1.2 vs. 1.9 ± 1.6 mmol/l,  = 0.042), proteinuria (72% vs. 28%,  = 0.001), and used more insulin (78% vs. 39%  = 0.0001), anti-hypertensive (95% vs. 80%,  = 0.0003) and lipid-lowering therapy (70% vs. 56%,  = 0.023). There was no association between DR and any of the or gene polymorphisms studied, although there were ethnic differences. After adjustment, diabetes duration (OR 1.05, 95% CI 1.01-1.08), presence of proteinuria (OR 4.15, 95% CI 1.70-10.11) and use of insulin therapy (OR 3.38, 95% CI 1.60-7.12) were associated with DR.

CONCLUSION

Hyperglycemia, duration of diabetes and proteinuria are associated with DR in Indian and African patients in South Africa, whereas and gene polymorphisms were not associated with DR.