title: Angiotensin-converting enzyme gene polymorphism and carotid artery wall thickness: a meta-analysis.
abstract: OBJECTIVE
  Many studies have investigated the association between the angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism and carotid artery intima-media thickness (IMT); however, most studies were small and conducted in selective samples. The aim of this study was to evaluate this association by performing a meta-analysis on published articles.
  
  
  METHODS
  We searched Medline for articles studying the association between the ACE I/D polymorphism and carotid IMT. Twenty-six studies were found; 23 articles containing 9833 subjects were qualified to enter the meta-analysis. We classified those articles on the basis of their samples into high-risk and low-risk populations and white and Asian ethnic groups. IMT was used as a continuous variable, and data were analyzed with the Cochrane Review Manager.
  
  
  RESULTS
  A significant positive association was present between the D allele and common carotid IMT (weighted mean difference between DD and II genotypes, 0.23 mm x 10(-1); P<0.01). The association was stronger among high-risk populations. The point estimates of DD versus II were higher than those of ID versus II.
  
  
  CONCLUSIONS
  Our meta-analysis showed evidence of a positive association between the D allele of the ACE gene and common carotid IMT. The overall results were concordant in both ethnic groups.
authors.affiliation: Department of Epidemiology and Biostatistics, Erasmus Medical Center, Rotterdam, The Netherlands.
authors.forename: Fakhredin A
authors.initials: FA
authors.lastname: Sayed-Tabatabaei
authors.forename: Jeanine J
authors.initials: JJ
authors.lastname: Houwing-Duistermaat
authors.forename: Cornelia M
authors.initials: CM
authors.lastname: van Duijn
authors.forename: Jacqueline C M
authors.initials: JC
authors.lastname: Witteman
mesh_terms: D000328:Adult; D000368:Aged; D000483:Alleles; D044466:Asian People / Q000235:genetics; D002339:Carotid Arteries / Q000000981:diagnostic imaging*; D005260:Female; D005787:Gene Frequency; D006801:Humans; D008297:Male; D008875:Middle Aged; D007703:Peptidyl-Dipeptidase A / Q000235:genetics*; D011110:Polymorphism, Genetic; D012306:Risk; D017539:Tunica Intima / Q000000981:diagnostic imaging; D017540:Tunica Media / Q000000981:diagnostic imaging; D014463:Ultrasonography; D044465:White People / Q000235:genetics
chemical_list: D007703:Peptidyl-Dipeptidase A