Comparison of methods for urinary albumin determination in patients with type 1 diabetes

Abstract

We tested the correlation of the albumin-to-creatinine ratio (A/C) in an early-morning urine sample, measured with a commercial kit (DCA 2000 ® ), with the conventional immunoturbidimetric determination in the laboratory and with overnight albumin excretion rate (reference method). Fifty-five type 1 diabetic adolescents had their first-morning urine collected on the 1st and 8th day of the period. Urinary albumin and creatinine were determined immediately using the DCA 2000 ® kit. Samples were also stored for laboratory analysis. To evaluate the correlation between early-morning urinary A/C ratio and overnight albumin excretion rate, 16 subjects had a timed overnight urine collection. A/C ratios determined with the DCA 2000 ® kit and by the laboratory method were 13.1 ± 20.5 and 20.4 ± 46.3 mg/g, respectively. A/C results by both methods proved to be strongly correlated (r = 0.98, P<0.001). DCA 2000 ® -determined A/C showed 50% sensitivity and 100% specificity when compared to the reference method. Spot urinary A/C of the subset of 16 subjects significantly correlated with their overnight albumin excretion rate (r = 0.98, P<0.001). Intraindividual variation ranged from 17 to 32% and from 9 to 63% for A/C and overnight albumin excretion rate, respectively. In conclusion, an early-morning specimen should be used instead of timed overnight urine and the A/C ratio is an accurate, reliable and easily determined parameter for the screening of diabetic nephropathy. Immediate measurement of the A/C ratio is feasible using the DCA 2000 ® kit. Intraindividual variability indicates the need for repeated determinations to confirm microalbuminuria and the diagnosis of incipient diabetic nephropathy. Correspondence

Validation of a Human Immunoturbidimetric Assay to Measure Canine Albumin in Urine and Cerebrospinal Fluid

“…4 In humans, microalbuminuria and overt albuminuria are defined as urine albumin concentrations of 2-20 mg/dl and above 20 mg/dl, respectively. 9,12,15 Recent studies 15 validated an ELISA kit designed to measure canine albumin in different biological specimens and showed that pathological albuminuria commonly occurs in dogs, even if the normal range is not well established. Unfortunately, ELISA is time consuming and can hardly be carried out as a routine screening test.…”

Comparison between different methods of urine collection for estimation of albumin-creatinine ratio in patients with type-2 diabetes mellitus

“…Various previous studies also give support towards this factor due to easy collection, low cost and high sensitivity [2,[35][36][37].…”

“…Diabetic nephropathy (DN) is the most frequent single cause of end-stage renal disease in many countries [1]. Hyperfiltration and microalbuminuria characterize the clinical stages of DN [2]. Increased levels of albumin in the urine have been clearly established as an important determinant for renal complication of diabetes [3][4][5].…”

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

“…There are many studies which compared either FMV or RUS and albuminuria measure such as UAC and/or ACR as alternative to measurement of 24-h UAE [21][22][23][24][25][26][27]. Few studies correlated ACR in either single FMV or RUS [17,28,29].…”