AbstractObjective: To evaluate early stages of atherosclerosis and predisposing factors in childhood diabetes compared to age- and sex matched healthy control subjects. Research design and Methods: All children and adolescents with type 1 diabetes, aged 8-18 years in Health Region South-East in Norway were invited to participate in the study (n= 800). 40% (n= 314) agreed to participate and were compared to 118 age-matched healthy controls. Carotid artery Intima Media Thickness (cIMT) and elasticity was measured using standardized methods. Results: Mean age of the diabetic patients was 13.7 years, diabetes duration 5.5 years and HbA1c 8.4%. 97% were using intensive insulin treatment, 60% insulin pumps. Diabetic patients had more frequently elevated cIMT than healthy controls: 19.5% were above 90(th) centile of healthy controls and 13.1% above 95(th) centile (p