P1197 Citation: Atherosclerosis Supplement 2009, Vol. 10, Issue 2 METABOLIC CONTROL AND ARTERIAL VASOREACTIVITY IN CHILDREN WITH TYPE I DIABETES USING INSULIN PUMP M Sebestjen, N Battelino, T Battelino, I Keber Department of Angiology, University Clinical Centre Ljubljana, Ljubljana; University Children's Hospital, University Clinical Centre Ljubljana, Ljubljana Children with type I diabetes mellitus have impaired endothelial function which is the first change in atheroslcerotic process. The aim of our study was to find out whether arterial vasoreactivity in children with type I diabetes mellitus using insulin pump is depending on the intensitivity of metabolic control. We studied 97 children with type I diabetes, aged between 7 and 18 years. The children were classified into two groups according to HbA1c below (Group 1) or more than (Group 2) 8,0%. In all participants physical examination, measurements of serum lipids, glucose, HbA1c and ultrasonographic studies of brachial artery vasoreactivity were performed. Children in group 1 were significantly younger than those in group 2 (10,3 ±1,9 and 15,6 ± 1,9 years; respectively (p<0,0001)). The mean values of blood glucose were 8,1 ± 3,2 mmol/l and 9,3 ± 4,0 mmol/l (p=ns), while mean values of HbA1c were 7,4 ± 0,4% and 9,3 ± 1,7%; respetivly (p<0,0001). Total (4,0 ± 0,6 mmol/l and 4,5 ± 0,7 mmol/l (p= 0,007)) and LDL cholesterol (2,0 ± 0,5 mmol/l and 2,4 ± 0,7 mmol/l (p= 0,04)) were lower in group 1 than in group 2. No difference were found in HDL cholesterol, and systolic and diastolic blood pressure. The flow mediated dilatation (FMD) was 6,7 ± 4,5% and 3,2 ± 5,4% (p= 0,02) in group 1 and group 2; respectively. Only HbA1c emerged as independed predictor of FMD. The value of HbA1c is the most important predictor of FMD in children with type I diabetes mellitus using insulin pump. Lifestyle modifications and strickt control of HbA1c early in childhood are important to prevent early atherosclerostic changes in these population.