Abstract 
         
         Insulin resistance, as well as vascular disease, both share a relevant genetic background
            taking the influence of a positive family history of these disorders. On the other
            hand, insulin resistance is associated with a proatherosclerotic disturbance in nitric
            oxide dependent vasodilation, probably contributing to the link between these two
            disorders. We examined the association between nitric oxide dependent vasodilation
            (measured with high resolution ultrasound at 13 MHz) and three relevant NO-synthase
            (eNOS)-polymorphisms in 200 insulin resistant subjects participating in the Tuebinger
            Lifestyle Intervention Program (TULIP). This study revealed that carriers of the eNOS
            intron 4 polymorphism (aa 2.16%; ab 24.2%; bb 73.2%) show significantly worse endothelial,
            and thereby eNOS dependent vasodilation (p=0.03, multivariate ANOVA), as compared
            to wildtype carriers. The 5′ UTR T-786C and the G894 T polymorphism did not show any
            influence on eNOS-activity. In subjects at increased risk to develop type 2 diabetes,
            the eNOS intron 4 polymorphism is independently associated with endothelial function
            as indicated by disturbed endothelial NO production. Due to the high prevalence and
            the relatively strong effect, this polymorphism might help to identify subjects at
            increased risk for atherosclerosis associated with overweight and insulin resistance.
         
         
         
            
Key words 
         
         
            eNOS - polymorphism - flow-mediated dilation - intima-media-thickness - risk score
               - insulin resistance
          
       
    
   
      
         References 
         
         
             
         
         Correspondence 
         kilian.rittig@med.uni-tuebingen.de