Adolescent Type 1 Diabetes Cardio-Renal Intervention Trial (AdDIT): Urinary Screening and Baseline Biochemical and Cardiovascular Assessments

Abstract

OBJECTIVE We assessed the association between early increases in albumin excretion and cardiovascular (CV) and renal markers in a large cohort of young people with type 1 diabetes. RESEARCH DESIGN AND METHODS As part of preliminary screening for a multicenter, randomized controlled trial of statins/ACE inhibitors, we measured albumin–creatinine ratio (ACR) in six early morning urine samples from 3,353 adolescents (10–16 years of age) and calculated tertiles based on an established algorithm. From those subjects deemed to be at higher risk (upper ACR tertile), we recruited 400 into the intervention study (trial cohort). From those subjects deemed to be at lower risk (middle–lower ACR tertiles), we recruited 329 to the observation cohort. At baseline, vascular measurements (carotid intima-media thickness, pulse wave velocity [PWV], flow-mediated dilatation, digital pulse amplitude tonometry), renal markers (symmetric dimethylarginine, cystatin C, creatinine), and CV disease markers (lipids and apolipoproteins [Apo] A-1 and B, C-reactive protein, asymmetric dimethylarginine) were assessed. RESULTS Age- and sex-adjusted PWV was higher in the trial than in the observational cohort (5.00 ± 0.84 vs. 4.86 ± 0.70 m/s; P = 0.021). Similarly, non-HDL cholesterol (2.95 ± 0.83 vs. 2.81 ± 0.78 mmol/L; P = 0.02) and ApoB–ApoA-1 ratio (0.50 ± 0.14 vs. 0.47 ± 0.11; P = 0.04) were higher in the trial cohort. Cystatin C and creatinine were decreased (0.88 ± 0.13 vs. 0.90 ± 0.13 mg/L, P = 0.04; 51.81 ± 10.45 vs. 55.35 ± 11.05 μmol/L, P < 0.001; respectively) and estimated glomerular filtration rate (137.05 ± 23.89 vs. 129.31 ± 22.41 mL/min/1.73 m2; P < 0.001) increased in the trial compared with the observational cohort. CONCLUSIONS Our data demonstrate that in adolescents with type 1 diabetes, the group with the highest tertile of albumin excretion showed more evidence of early renal and CV disease than those in the lower tertiles.