Objective: To investigate the relationship between angiotensin converting enzyme (ACE) gene and endothelial dysfunction.
Methods: One hundred and ten type 2 diabetic patients without angiopathy were selected randomly, and PCR technique was used to determine their ACE genotypes. High resolution ultrasonography was performed to measure the changes in brachial artery diameter at rest, after reactive hyperemia (with increased flow producing an endothelium-dependent dilation) and after sublingual glyceryltrinitrate (GNT, an endothelium-independent dilator). Meanwhile, 50 healthy individuals were selected randomly as controls.
Results: In type 2 diabetes mellitus and control groups, the percentages for flow-mediated arterial dilation in patients with DD genotypes were 3.38% and 3.67% respectively, which were significantly lower than those in patients with II genotypes (4.12% and 4.68% respectively, P<0.05). The baseline blood vessel size, baseline blood flow and GNT induced dilation in both groups showed no significant differences among ACE genotypes (P>0.05). By multiple stepwise regression analysis, reduced flow-mediated arterial dilation was associated with age, baseline vessel size, low density lipoprotein cholesterol(LDL-C), Lp(a), D allele, fasting blood glucose (FBG), postparandial blood glucose (PPBG), HbA1c, duration of diabetes in type 2 diabetic patients (P<0.0005).
Conclusion: ACE DD genotype is related to endothelium-dependent arterial dilation in the early stage of type 2 diabetes mellitus and in healthy individuals.