Effect of statins on proteolytic activity in the wall of abdominal aortic aneurysms

Background: The aim of this study was to examine the effect of statin treatment on the activity of proteases in the wall of abdominal aortic aneurysms (AAAs). Methods: The activities of matrix metalloproteinases (MMPs) 9 and 3, cathepsins B, H, K, L and S, and the cystatin C level were measured in extracts of AAA wall taken from 82 patients undergoing AAA repair; 21 patients were receiving statin treatment before surgery. All values were standardized against soluble protein (SP) concentration in the extract, and reported as median (interquartile range) or mean(s.e.m.). Results: The two groups had similar demographics. Reduced activity of MMP‐9 (43 (34–56) versus 80 (62–110) pg per mg SP; P < 0·001), cathepsin H (183 (117–366) versus 321 (172–644) nmol 4‐methylcoumarin‐7‐amide released per mg SP; P = 0·016) and cathepsin L (102 (51–372) versus 287 (112–816) µmol 7‐amino‐4‐trifluoromethylcoumarin released per mg SP; P = 0·020) was found in the statin‐treated aortas compared with AAAs from patients not taking a statin. The statin‐treated group had lower MMP‐3 activity, but this did not reach statistical significance ( P = 0·053). Cystatin C levels were higher in statin‐treated aortas than in controls (41·3(3·1) versus 28·9(2·1) ng per mg SP; P = 0·003). Conclusion: Statins decreased the activity of proteases that have been implicated in aneurysm disease. Copyright © 2007 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.