Correlative Study of Diabetic Retinopathy with HbA1c and Microalbuminuria

Abstract

INTRODUCTION: Type 2 diabetes is now a common and serious global health problem, which, for most countries, has evolved in association with rapid cultural and social changes, ageing populations, increasing urbanisation, dietary changes, reduced physical activity and other unhealthy lifestyle and behavioural patterns. The risk of developing diabetic retinopathy or other microvascular complications of diabetes depends on both the duration and severity of hyperglycemia. The other microvascular complication associated with diabetes is diabetic nephropathy. Therefore, correlation between microalbuminuria and HbA1C level with diabetic retinopathy has been explored in this study.

MATERIAL AND METHOD: A hospital based cross-sectional study was conducted including 444 consecutive pre diagnosed cases of type II diabetes mellitus attending the Diabetic Clinic of Department of Medicine of our facility. All cases were subjected to complete ocular examination after taking demographic and medical history. Diabetic Retinopathy was graded as per ETDRS categories. Biochemical investigations like serum creatinine, serum urea, urine microalbumin levels, Blood sugar (fasting/post prandial), HbA1c were done.

RESULTS: Out of 444 cases, Male to female ratio was 0.88: 1, where majority (54.73%) were aged between 41-60 years. 246 patients who did not suffer from retinopathy were grouped as Group I, while the rest of 198 patients having retinopathy were categorized as Group II. This was further divided into IIA suffering from Very mild to moderate NPDR (58.59%), IIB suffering from Severe to very severe NPDR (29.29%), and those suffering from Proliferative diabetic retinopathy were grouped as IIC (12.12%).A statistical significant association with severity of diabetic retinopathy and duaration of diabetes was observed.A statistically significant association between severity of diabetic retinopathy and HbA1c values was found (p < 0.001). A statistically significant association between grade of microalbuminuria and severity of diabetic retinopathy was observed (p < 0.001). On trivariate analysis of severity of diabetic retinopathy, HbA1C level and microalbuminuria grade, a statistically significant difference in prevalence of diabetic retinopathy in different HbA1c levels with microalbuminuria Grade 0 was found (p < 0.001). The difference in proportion of patients suffering from very mild to moderate diabrtic retinopathy with duration of diabetes was found to be statistically significant (p < 0.001) in grade I microalbuminuria. Difference in proportion of patients suffering from diabetic retinopathy with duration of diabetes was found to be statistically significant in grade II microalbuminuria (p < 0.001). In grade III microalbuminuria, this difference was not found to be statistically significant (p = 0.093).

CONCLUSION: Microalbuminuria poses a risk for diabetic retinopathy which is affected by duration of diabetes and level of glycemic control. Microalbuminuria of higher grades is a strong predictor for occurrence and severity of diabetic retinopathy.