The primary goal of managing childhood type 1 diabetes is to prevent or delay retinal and renal microvascular complications. Because lesions are silent for a long time,1 glycated haemoglobin (HbA_1c) concentrations are used as a surrogate measure of the adequacy of treatment to avoid diabetic complications. Most of our knowledge of the relation between control of diabetes and the risk of renal complications of diabetes comes from data in adults and adolescents, so it is important to have a precise evaluation of the risk in children.

In the accompanying paper, Amin and colleagues report on the risk of diabetic renal disease in the Oxford regional prospective study, a population based cohort study of children with type 1 diabetes.2 The prevalence of microalbuminuria was about 25% and 50% after 10 and 20 years of diabetes, respectively. The natural course of microalbuminuria was such that about half of patients reverted at least transiently to normoalbuminuria and 13% progressed to macroalbuminuria. The study answers important questions for those …