Intermittent microalbuminuria in children with type 1 diabetes mellitus without clinical evidence of nephropathy.

Microalbuminura (MA) was determined in 127 children and adolescents (age 3-21 years) with type 1 (insulin-dependent) diabetes mellitus. Patients with clinical evidence of long-term complications or macroproteinuria were excluded. Urinary albumin excretion was measured in a nocturnal 12-h collection and correlated with the albumin/creatinine ratio of a urine sample freshly voided on the morning immediately following the collection. The patients were divided into group A (n = 83, age less than 16 years, duration of diabetes 1-13 years, mean 4.4) and group B (n = 44, age greater than 16 years, duration of diabetes 1-19 years, mean 8.7) and compared with appropriate controls. MA above 15 micrograms/min was present in 11 of 83 (13.3%) patients in group A and in 7 of 44 (15.9%) in group B. In a repeat urine collection at least 3 months later elevated MA persisted in 1 of 11 (group A) and in 4 of 7 (group B) patients. There was no correlation between increased MA in a 12-h urine collection and the albumin/creatinine ratio in a subsequently voided urine sample. MA was not strictly dependent on age, sex, duration of diabetes, haemoglobin A1, mean arterial blood pressure, plasma creatinine, creatinine clearance or serum beta-2-microglobulin. Further systematic studies and careful follow up are necessary to appraise whether intermittent MA is indeed an early manifestation of incipient kidney disease in children with type 1 diabetes.