Screening of Type 2 Diabetes Mellitus Patients for Micro-albuminuria and Its Relationship with Diabetic Retinopathy

Aims: The aim of present study was to find out the prevalence of micro-albuminuria and its relationship with diabetic retinopathy in type 2 diabetes mellitus (T2DM) patients.

Study Design: Cross-sectional study.

Place and Duration of Study: Department of Biochemistry and Department of Medicine, University College of Medical Sciences and Guru Teg Bahadur Hospital, Delhi, India, between September 2013 and August 2015.

Methodology: Total 387 clinically diagnosed T2DM patients with age range 30-65 years were enrolled for the study. Morning spot urine samples were collected for analysis of urinary albumin and creatinine on two separate occasions. Serum and urine creatinine were carried out by alkaline picrate Jaffee´s kinetic method. Urine albumin was estimated by turbidometric method by using nephelometer (Nephstar®, Goldsite Diagnostics Inc., USA). On the basis of albumin/creatinine ratio (ACR), patients were classified as normo-albuminuric (albumin/creatinine ratio <30 mg/g creatinine); micro-albuminuric (albumin/creatinine ratio 30-299 mg/g creatinine) and macro-albuminuric (albumin/creatinine ratio ≥300 mg/g creatinine). Patients underwent ophthalmologic examination including fundoscopy for the detection of diabetic retinopathy. Estimated glomerular filtration rate (eGFR) was calculated by Modification of Diet in Renal Disease (MDRD) equation. The plasma glucose, glycosylated hemoglobin, blood urea, serum sodium, serum potassium, total cholesterol, triglyceride and HDL cholesterol etc. investigations were carried out in each patient.

Results: Out of total 387 T2DM patients screened, 159 (41%) were normo-albuminuric, 162 (41.8%) were micro-albuminuric and 66 (17%) were macro-albuminuric. The overall prevalence of micro-albuminuria was 41.8%. The prevalence of micro-albuminuria was 51.2% among males and 48.8% among females. The percentage of patients having micro-albuminuria was found to be increased with increasing duration of diabetes. Micro-albuminuria showed significant correlation with duration of diabetes (p<0.001), serum creatinine (p<0.001), HbA1c (p<0.01) and with eGFR (p<0.001). The overall prevalence of diabetic retinopathy in T2DM patients in our study was 29.7% and when the patients were classified according to their albuminuria the prevalence of diabetic retinopathy was found to be 13.8% in normo-albuminuric group, 33.9% in micro-albuminuric group and 57.5% in macro-albuminuric group.

Conclusions: The present study suggests that the onset of micro-albuminuria in T2DM patients is associated with increasing duration of diabetes, poor glycemic control and presence of diabetic retinopathy. Presence of micro-albuminuria in T2DM patients having <5 years of duration of diabetes suggest screening of micro-albuminuria would be beneficial for early detection of DN.