Journal of Research in Medical Sciences1735-199511120060101Endothelial Function in Adolescents with a History of Premature Coronary Artery Disease in One Parent1823ENMHashemiAssistant Professor, Department of Internal Medicine, Isfahan University of Medical Sciences, Isfahan. mohammad_hashemi@med.mui.ac.irYKianiRBasiratniaFBayat2006030620060306Background: In young adults, a family history of premature coronary artery disease (CAD), as well as genetic and environmental factors are independent risk factors for coronary artery disease. Methods: Endothelial function was studied in 30 children (21 boys and 9 girls with mean age of 14.9 +/- 2.3 years old) of patients with documented CAD (men 45 and women 50 years old). Chidren did not have any history of diabetes mellitus, dyslipidemia, hypertension, and smoking (active/passive). Using vascular ultrasound, we measured resting Basal Brachial artery Diameter (BBD) and Endothelium-Dependent Dilatation (EDD) in response to increased flow and sublingual glyceryltrinitrate (GTN), an Endothelium-Independent Dilation (EID). These parameters were also measured in 30 control subjects with normal parents (18 boys and 12 girls with mean age of 14.2 +/- 2/5years old) and results were compared with each other. Results: Adolescents in CAD group had abnormal Endothelial Dependent Dilatation or EDD/BBD (8.5 +/- 3.4% vs 11.8 +/- 4.5% in control subjects; P= 0.003).Endothelial Independent Dilatation (EID/BBD) in the positive fimily history group was significantly more than control subjects (18.5 +/- 6.7% vs 11.9 +/- 5.2%; P