First morning urinary albumin concentration is a good predictor of 24-hour urinary albumin excretion in children with Type I (insulin-dependent) diabetes

Abstract

Twenty-four hour urinary albumin excretion was measured in 97 children with Type 1 (insulin-dependent) diabetes and found to have a geometric mean of 6 mg/day (range 1–38 mg/d). The same geometric mean of 6 mg/day (range 1–45 mg/d) was found in 120 normal children. The relationship of 24-h urinary albumin excretion to the albumin concentration (mg/1) and to the ratio of albumin: creatinine (mg: mmol) on first morning urine samples in 64 patients was highly significant (r=0.93 and r=0.62 respectively, p < 0.001). In 41 patients, the relationship between 24-h urinary albumin excretion and albumin concentration upon urine samples at various times was assessed. The correlation was highest on the first morning sample (r=0.86); 09.00h to 13.00 h, 0.51; 13.00 h to 18.00 h, 0.68; 18.00 h to 23.00 h, 0.32. High sensitivity and moderate specificity was obtained using a first morning albumin concentration of greater than 20 mg/l to detect increased albumin excretion. These results show that the measurement of albumin concentration on the first morning urine sample can be used for a screening test for micro-albuminuria in children.