Risk factors of diabetic retinopathy in patients with type 2 diabetes mellitus

Aim: To investigate the association of systolic, diastolic hypertension, older age, longer duration of diabetic state, poorly controlled blood sugar(HbA1c) with diabetic retinopathy in patients of type 2 DM. Methodology: This is a case control study in which 1000 patients coming to Ophthalmology Department of Post Graduate Institute of Medical Sciences, Rohtak (a tertiary care hospital in India) were included. To avoid the influence of nephropathy, the patients with proteinuria were excluded from the study. Age for sample size ranges between 40–80 years. These 1000 patients were divided into two groups – group A with patients having diabetic retinopathy and group B with patients not having diabetic retinopathy. Systolic and diastolic blood pressure, fasting blood sugar, random blood sugar, HbA1c were investigated. Results: In our study, we found that patients with DR were having have higher systolic BP than patients without DR (138 ±14 vs.126 ± 15, P<0.001). However no statistically significant variation was found in diastolic BP of both the groups. The mean age of patients with DR was significantly higher (P<0.001) in comparison to patients without DR (58 ± 8 vs. 54 ± 7 years). A significant difference was observed in the mean duration of diabetes (12 ± 5 vs. 8 ± 5 years, P<0.001) between patients with DR and diabetics without retinopathy. The % of HbA1C measured in DR patients was significantly higher than non-DR patients evidencing the fact that long term poor control of blood sugar levels had adverse effect on retina (8.16 ± 0.52 vs. 7.04 ± 0.32). Conclusions: Our study evidence that DR is significantly associated with older age, longer duration of diabetic state, poorly controlled blood sugar(HbA1c) and systolic hypertension.