Circulating matrix metalloproteinases and their inhibitors in hypertension

Growing experimental evidence indicates that matrix metalloproteinases (MMPs) are implicated in many cardiovascular diseases including hypertension and its chronic complications. It is now clear that MMPs have many more substrates other than components of the extracellular matrix. In fact, intracellular targets now include those associated with the cardiovascular system. Clinical studies have suggested that circulating MMPs may predict cardiovascular morbidity and mortality. It is highly probable that increased MMPs may predispose hypertensive patients to additional complications and clinical sequelae. In this article, we review the basic principles linking MMP activity with hypertension and summarize clinical studies examining two specific MMPs (MMP-2 and -9) in hypertension. We also discuss how antihypertensive drugs may affect MMPs and their endogenous inhibitors, i.e., tissue inhibitors of matrix metalloproteinases (TIMPs). Circulating MMPs may predict increased risk of developing cardiovascular complications associated with hypertension. As such, patients could benefit from early pharmacologic intervention including use of MMP inhibitors.