Recent evidence indicates that metabolism of
elastin may be altered in patients with different types of infrarenal
aortic disease and that the phenotypic expression of
aortic disease may be dependent on the balance between aortic
elastase and
antiprotease activity. The
dipeptide L-valyl
proline (LVP) is a specific amino acid sequence for
elastin and can be quantitated by high performance liquid chromatography analysis of the urine. This study was done to determine if alterations in systemic
elastin metabolism could be detected in patients with different types of infrarenal
aortic disease by quantitating urinary LVP. Patients were divided into one of five groups and had urine analyzed for LVP. These are control, no known
aortic disease (n = 12); occlusive
aortic disease (n = 10); elective
abdominal aortic aneurysms (AAA) (n = 26); ruptured AAA (n = 5), and multiple
aneurysms (n = 4). Urine values were correlated with aortic
elastase and aortic
antiprotease activity. Urinary LVP was significantly higher in patients with multiple
aneurysms (1,209 micrograms per milliliter of urine) as compared with all of the other groups. Patients with elective AAA had significantly higher urinary LVP (40.5 micrograms per milliliter of urine) than patients with occlusive disease (9.1 micrograms per milliliter of urine) and those in the control group (4.2 micrograms per milliliter of urine). Patients with ruptured AAA did not have significantly elevated urinary LVP compared with other groups (18.6 micrograms per milliliter of urine). Urinary LVP increased significantly as aortic
elastase and aortic
elastase and
antiprotease activity increased. These data suggest that
elastin metabolism, as reflected by urinary LVP, is altered in patients with aortic aneurysmal disease and provide further evidence to support the concept that systemic
elastin metabolism is altered in patients with different types of infrarenal aortic pathologic findings.