Comparison of 24 hour urine albumin and spot urine albumin to creatinine rattio as a predictor of diabetic nephropathy

ABSTRACT

Twenty four hours urine albumin is frequently used for prediction of the extent of nephropathy. Spot urine albumin to creatinine ratio has been recently introduced as an alternative to 24 hours urine albumin. Aims and objectives of the current study were to compare and contrast 24 hours urine albumin and spot urine albumin to creatinine ratio as a predictor of nephropathy. Two hundred cases of diabetes were selected for 24 hours urine albumin and spot urine albumin to creatinine ratio. Urine samples containing RBC 's or pus cells were excluded from the study. Twenty four hours urine albumin was estimated by pyrogallol method. First morning urine specimen was used for albumin to creatinine ratio. Creatinine was estimated by Jaffe reaction on semi-automated analyzer. Results revealed that mean 24 hours urine albumin was 693 mg/24 hours [reference range < 30 mg/24 hours], while mean albumin to creatinine ratio was 22.7 mg/mmol [reference range < 3 mg/mmol]. Fifty seven cases were having microalbuminuria, 103 cases had macroalbuminuria whereas 40 cases had normal urine albumin. Forty eight cases showed albumin to creatinine ratio in the normal range, 88 cases in microalbuminuria range while 64 cases had albumin to creatinine ratio in macroalbuminuric range. Correlation of 24 hours urine albumin versus urine albumin to creatinine ratio was 0.97, p value < 0.01. It was concluded that there was no significant difference between 24 hours urine albumin and spot urine albumin to creatinine ratio as a predictor of nephropathy, besides yielding immediate results and spot convenient sampling. It is recommended that spot urine albumin to creatinine ratio is a simple, clear, attractive and right predictor of nephropathy and can safely replace 24 hours urine sample for convenience of the patient, pathologist as well as the physician