A Comparative Study of Clinical Utility of Spot Urine Samples with 24-h Urine Albumin Excretion for Screening of Microalbuminuria in Type 2 Diabetic Patients

Abstract

Twenty-four hour urinary albumin excretion (UAE) is considered as gold standard method for albuminuria measurement, but collection of 24-h urine is inconvenient. The aim of present study was to evaluate whether albumin: creatinine ratio (ACR) and urinary albumin concentration (UAC) in different spot urine samples correlate or not with 24-h UAE for screening of microalbuminuria in type 2 diabetic patients. We collected first morning void (FMV), random urine sample (RUS) and 24-h urine, separately on consecutive days from 104 type 2 diabetic patients. ACR and UAC in each spot urine sample compared with 24-h UAE with regard to Pearson correlation coefficient. Pearson's correlation of albumin: creatinine ratio (ACR) with 24-h UAE was (r = 0.802 and 0.623) in first morning void (FMV) and random urine sample (RUS), respectively. Pearson's correlation coefficient of urinary albumin concentration (UAC) compared with 24-h UAE was (r = 0.943 and 0.920), in FMV and RUS, respectively, P < 0.01. Results revealed that values in first morning void (FMV) were better correlated with 24-h urinary albumin excretion (UAE), than the values in random urine sample (RUS). We conclude that the first morning void (FMV) may be able to replace 24-h urine collection, preferably urinary albumin concentration (UAC) in the initial screening of microalbuminuria in diabetic patients.

Electronic supplementary material: The online version of this article (doi:10.1007/s12291-011-0136-0) contains supplementary material, which is available to authorized users.

Keywords: Diabetes mellitus; Microalbuminuria; Screening; Spot urine sample; Urinary albumin concentration.

Fig. 1

Age distribution of patients (N = 104)

Fig. 2

Scatterplot graph of Pearson’s correlation between spot 1 (FMV) and 24-h UAE. a spot 1 ACR (mg/g) versus 24-h UAE (mg/24 h), b spot 1 UAC (mg/l) versus 24-h UAE (mg/24 h)

Fig. 3

Scatterplot graph of Pearson’s correlation between spot 2 (FMV) and 24-h UAE. a spot 2 ACR (mg/g) versus 24-h UAE (mg/24 h), b spot 2 UAC (mg/l) versus 24-h UAE (mg/24 h)

Fig. 4

Scatterplot graph of Pearson’s correlation between spot 3 (RUS) and 24-h UAE. a spot 3 ACR (mg/g) versus 24-h UAE (mg/24 h), b spot 3 UAC (mg/l) versus 24-h UAE (mg/24 h)