Matrix metalloproteinase-9 and tissue inhibitor metalloproteinase-1 levelsin essential hypertension. Relationship to left ventricular mass and anti-hypertensive therapy

To test the hypothesis that the activity of enzymes degrading the extracell ular matrix in hypertensive patients are abnormal, and that the treatment o f hypertension will normalise these abnormalities, we measured the serum le vels of metalloproteinase MMP-9, and its inhibitor, tissue metalloproteinas e inhibitor (TIMP-1). Thirty-two patients with untreated hypertension (BP 1 68/96) had significantly lower levels of both MMP-9 and TIMP-1 when compare d to 24 matched normotensive controls (BP 123/80) (P<0.001). There was no s ignificant correlation between MMP-9 and TIMP-1 levels (P>0.2). In the pati ents, there were no significant correlations observed between left ventricu lar mass, Doppler V-E/V-A ratio (an index of diastolic function), blood pre ssure, left ventricular mass index and either MMP-9 or TIMP-1 levels (all P =NS). Levels of MMP-9 and TIMP-1 were not significantly altered after 2 mon ths of antihypertensive treatment of 29 patients despite mean blood pressur e falling from 170/96 to 143/85 mm Hg (P<0.001). Correspondingly, there wer e also no significant alterations in indices of diastolic function and left ventricular mass. Our study suggests that the proteolytic activities of MM P-9 and TIMP-1 are depressed in hypertensive patients and were not signific antly affected by short-term antihypertensive treatment. The relationship b etween collagen metabolism in hypertensive subjects, especially in those wi th cardiac hypertrophy, and the effects of treatment needs to be further ex plored in larger trials over a longer period of time. (C) 2000 Elsevier Sci ence Ireland Ltd. All rights reserved.