title: Association between polymorphisms of the renin angiotensin system and carotid stenosis.
abstract: OBJECTIVE
  Carotid stenosis is a common manifestation of systemic atherosclerosis. Apart from traditional risk factors, genetic determinants, such as polymorphisms of the renin angiotensin system (RAS), may be relevant in modulating the atherosclerotic process leading to carotid stenosis. In this study, we investigated the role of angiotensin-converting enzyme (ACE) I/D and -240A>T, angiotensinogen (AGT) M235T, and angiotensin type 1 receptor (AGTR1) 1166A > C polymorphisms in modulating the susceptibility to the disease.
  
  
  METHODS
  Eight hundred twenty-one consecutive patients with severe carotid stenosis (≥70%) and 847 control subjects were investigated.
  
  
  RESULTS
  A significant difference in genotype distribution (P < .0001) and allele frequency (P < .0001) between patients and controls for the ACE I/D polymorphism, but not for the other single-nucleotide polymorphisms investigated, was observed. The ACE D allele frequency was significantly higher in patients without traditional risk factors in comparison with that observed in those with at least one risk factor (0.71 vs 0.61; P = .04). The ACE D allele significantly influenced carotid stenosis under dominant, recessive, and additive model of inheritance at both univariate (P < .0001) and multivariate analysis (P < .0001). When the combined effect of RAS unfavorable alleles was considered, patients carrying less than three alleles had a lower risk of carotid stenosis (odds ratio [OR], 0.79 [0.63-0.99]; P = .05), while carriers of more than four unfavorable alleles had an increased risk (OR, 1.44 [1.12-1.84]; P = .004), in comparison with subjects carrying three or four unfavorable alleles. ACE D allele frequency was similar in patients with and without additional atherosclerotic localizations (0.61 vs 0.62, respectively).
  
  
  CONCLUSIONS
  Our findings evidence a role for ACE I/D polymorphism in influencing the susceptibility to carotid stenosis, even in the absence of traditional risk factors. Interestingly, our findings provided further information concerning the role of this polymorphism in modulating the atherosclerotic process apart from its different localizations.
authors.affiliation: Department of Medical and Surgical Critical Care, University of Florence, Florence, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Sticchi
authors.forename: Ilaria
authors.initials: I
authors.lastname: Romagnuolo
authors.forename: Francesco
authors.initials: F
authors.lastname: Sofi
authors.forename: Giovanni
authors.initials: G
authors.lastname: Pratesi
authors.forename: Raffaele
authors.initials: R
authors.lastname: Pulli
authors.forename: Carlo
authors.initials: C
authors.lastname: Pratesi
authors.forename: Rosanna
authors.initials: R
authors.lastname: Abbate
authors.forename: Cinzia
authors.initials: C
authors.lastname: Fatini
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000808:Angiotensinogen / Q000235:genetics; D016893:Carotid Stenosis / Q000175:diagnosis / Q000235:genetics*; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D005260:Female; D005787:Gene Frequency; D020022:Genetic Predisposition to Disease; D006801:Humans; D007558:Italy; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D007703:Peptidyl-Dipeptidase A / Q000235:genetics; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D044140:Receptor, Angiotensin, Type 1 / Q000235:genetics; D012084:Renin-Angiotensin System / Q000235:genetics*; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed; D018615:Ultrasonography, Doppler, Color; D055815:Young Adult
chemical_list: C534931:AGT protein, human; C544065:AGTR1 protein, human; D044140:Receptor, Angiotensin, Type 1; D000808:Angiotensinogen; D007703:Peptidyl-Dipeptidase A