[Type 1 diabetes mellitus and nephropathy. Predicting factors in pediatric age]

To find the existence of early relationships between alterations in the glucidic metabolism and the glomerular and tubular basal function in diabetic insulin-dependent children without clinical evidence of diabetic nephropathy (DN).We determined blood pressure, basal plasma concentrations of glucose, glycosilated hemoglobin and total proteins, glomerular filtration rate (GFR), and the glucose, proteins, calcium, phosphorus, uric acid, sodium, potassium and chloride excretions in diurnal, nocturnal and 24-hour urine samples in 43 diabetic children and 13 healthy controls.The microproteinuria mean value in all urine samples (always less than 15 micrograms/min/1.73 m.2), the GFR and blood pressure were similar in both groups. In the diabetic children, we found an inverse correlation between age and 24-hour urine microproteinuria (r-0.33; p less than 0.05) and between age and nocturnal urine microproteinuria (r-0.35; p less than 0.05). There was also a highly significant correlation between microproteinuria and the albumin/creatinine ratio in urine samples (r = 0.94, p less than 0.0001). Diabetic children showed a greater nocturnal excretion of calcium (p less than 0.05) and phosphorus (p less than 0.05).Our results suggest that microproteinuria, GFR and blood pressure have not served as predictors of DN in pediatric patients.