The Adolescent Type 1 Diabetes Cardio-renal Intervention Trial (AdDIT) was a pragmatic clinical trial designed to explore the benefits and risks of angiotensin-converting–enzyme (ACE) inhibitor and statin treatment in adolescents with type 1 diabetes deemed to be at increased risk for complications of their diabetes, based on high urinary albumin-creatinine ratios. We screened 4407 adolescents (10-16 years), identifying 1000 in the upper tertile for albumin-creatinine ratios; 443 were randomized to a placebo-controlled trial of an ACE inhibitor and a statin using a 2x2 factorial design with minimization for baseline characteristics. The primary outcome for both interventions was change in albumin excretion, assessed by albumin-creatinine ratios in three early morning urine samples collected every 6 months over two to four years, and expressed as area under the curve. Key secondary outcomes included development of microalbuminuria, progression of retinopathy, changes in glomerular filtration rate, lipids and cardiovascular risk measures (carotid intima-media thickness, high-sensitivity C-reactive protein and asymmetric dimethylarginine). At baseline, the upper tertile of albumin excretion, although within the normal range, was associated with early evidence of microvascular and macrovascular disease. Overall drug adherence was 75%, and serious adverse events were similar across groups. Statin therapy resulted in significant reductions in total, LDL-, non-HDL-cholesterol, triglycerides and ApoB-Apo-A1 ratio. Overall drug adherence was 75%, and serious adverse events were similar across groups. Further results of the primary and secondary outcomes will be presented.