Fibrillin-1 genotype is associated with aortic stiffness and disease severity in patients with coronary artery disease.
BACKGROUND
Elevated pulse pressure is associated strongly with adverse cardiovascular outcome; however, the genetic basis of this condition is unknown. This study examined whether genotypic variation in the extracellular matrix protein fibrillin-1, the Marfan gene, was associated with aortic stiffening and therefore could contribute to cardiovascular risk associated with pulse pressure elevation in coronary disease.


RESULTS
Patients (n=145; 113 men), 62+/-9 years of age (mean+/-SD), with angiographically confirmed coronary disease, were studied. Carotid applanation tonometry was used to assess central blood pressures, and in conjunction with Doppler velocimetry, to assess aortic input and characteristic impedance. Fibrillin-1 genotype was characterized by a variable nucleotide tandem repeat and 2 single-nucleotide polymorphisms. The variable nucleotide tandem repeat was a good predictor of underlying haplotypes with 3 genotypes (2-2, 2-4, and 2-3) accounting for 86% of the population. The 2-3 genotype had higher input impedance (P=0.002), characteristic impedance (P=0.005), and carotid pulse pressure (P=0.002) compared with the 2-2 and 2-4 genotypes. Disease severity assessed by previous angioplasties and the number of patients with a stenosis >90% was also greater in the 2-3 genotype. Furthermore, in a multivariate analysis, fibrillin-1 genotype and central pulse pressure were independent of conventional risk factors in determining coronary disease severity. There was no difference in age, sex ratio, body mass index, smoking status, cholesterol level, or medication among the 3 genotypes.


CONCLUSIONS
Although a causative link has not been shown, these data are consistent with an important role for fibrillin-1 genotype in cardiovascular risk associated with large-artery stiffening and pulse pressure elevation in individuals with coronary disease.
Medley
Tanya L
TL
Alfred and Baker Medical Unit, Baker Medical Research Institute Prahran, Victoria, Australia.
Cole
Timothy J
TJ
Gatzka
Christoph D
CD
Wang
William Y S
WY
Dart
Anthony M
AM
Kingwell
Bronwyn A
BA
D000483:Alleles; D001011:Aorta / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D001783:Blood Flow Velocity; D001794:Blood Pressure / Q000235:genetics; D001916:Brachial Artery / Q000503:physiopathology; D002339:Carotid Arteries / Q000503:physiopathology; D003324:Coronary Artery Disease / Q000473:pathology / Q000503:physiopathology*; D005260:Female; D000071838:Fibrillin-1; D000071837:Fibrillins; D005787:Gene Frequency; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D017078:Laser-Doppler Flowmetry; D015810:Linkage Disequilibrium; D008297:Male; D008840:Microfilament Proteins / Q000235:genetics*; D008875:Middle Aged; D015999:Multivariate Analysis; D011110:Polymorphism, Genetic; D012307:Risk Factors; D012720:Severity of Illness Index; D014463:Ultrasonography; D054392:Adipokines
D000071838:Fibrillin-1; D000071837:Fibrillins; D008840:Microfilament Proteins; C000605722:FBN1 protein, human; D054392:Adipokines