Introduction: Elevated plasma matrix metalloproteinase-9 (MMP-9) levels have been suggested to precede the development of microalbuminuria. As angiotensin-converting enzyme (ACE) inhibitors effectively reduce urinary albumin excretion (UAE), in the present study we have investigated the potential association of plasma MMP-9 levels with UAE and treatment effects of ACE-inhibition.
Material and methods: In a placebo-controlled randomised trial we determined plasma MMP-9 levels at baseline and after three months of randomisation to either placebo (n=202) or fosinopril (20 mg/day, n=204) treatment.
Results: Baseline plasma MMP-9 levels were not related to baseline UAE (r=-0.008, p=0.871). Three months of fosinopril treatment effectively reduced UAE compared to placebo treatment (-10.4+/-2.4 vs. 1.8+/-1.3 mg/24 hours, p<0.001, respectively). However, fosinopril treatment failed to significantly change plasma MMP-9 levels compared to placebo (-0.47+/-7.68 vs. 0.06+/-9.20, p=0.646, respectively). In addition, the change in UAE was not related with change in MMP-9 levels.
Conclusion: The effective reduction of UAE with fosinopril was not related to plasma MMP-9 levels.