Multiple sites of vascular dilation or aneurysmal disease and matrix metalloproteinase genetic variants in patients with abdominal aortic aneurysm

OBJECTIVE: The objective of this study was to assess whether functional genetic polymorphisms of matrix metalloproteinases (MMPs) 1, 3, 9, and 12 are associated with arterial enlargements or aneurysms of the thoracic aorta or popliteal arteries in patients with abdominal aortic aneurysm (AAA). METHODS: The associations between MMP1 (-1607 G in/del, rs1799750), MMP3 (-1171 A in/del rs35068180), MMP9 (13-26 CA repeats around -90, rs2234681, rs917576, rs917577), and MMP12 (G/T missense variation, rs652438) polymorphisms and enlargements or aneurysms of the thoracic aorta and popliteal arteries were tested in 169 consecutive AAA patients. RESULTS: Thoracic aorta enlargement or aneurysm (TE/A; maximum diameter, >35 mm) was detected in 34 patients (20.1% prevalence). MMP9 rs2234681 microsatellite was the only genetic determinant of TE/A in AAA patients (P = .003), followed by hypercholesterolemia and antiplatelet use. Carriers of both alleles with ≥22 CA repeats had a 5.9 (95% confidence interval, 1.9-18.6; P < .0001) increased odds of TE/A, and a score considering all three variables showed 98% negative predictive value and 30% positive predictive value for thoracic aortic aneurysm detection. Eighty-two popliteal artery enlargements or aneurysms (diameter >10 mm) occurred in 55 patients (33.1% prevalence). Carriers of MMP12 rs652438 C allele showed an 18% (P = .006) increased diameter in popliteal arteries and a 2.8 (95% confidence interval, 1.3-6; P = .008) increased odds of popliteal artery enlargement or aneurysm compared with TT genotype. CONCLUSIONS: Among patients with AAA, carriers of homozygous ≥22 CA repeats in MMP9 rs12234681 and of C allele in MMP12 rs652438 have a substantial risk of carrying thoracic and popliteal enlargements, respectively.