['Increased arterial stiffness is a marker of atherosclerosis and is recognised early in the course of type 2 diabetes mellitus (T2DM). Matrix metalloproteinases (MMP) and their tissue inhibitors (TIMP) are a family of proteolytic enzymes which are essential for the structure and function of large arteries. In this study, we examined for relationships between MMP and TIMP-1 and indices of arterial stiffness in subjects with T2DM.', 'A total of 60 subjects with T2DM and 60 nondiabetic subjects were recruited. Aortic distensibility (AD) was assessed noninvasively by ultrasonography and augmentation index by pulse wave analysis.', 'The values of AD were lower in subjects with T2DM than in controls (P<.001), while those of augmentation index were not significantly different between the two groups. Plasma concentrations of MMP-2 and MMP-9 were not different between diabetic and nondiabetic participants, while those of TIMP-1 were lower in the diabetic patients (P=.005). In the diabetes group, no significant associations were found between either AD or augmentation index and MMPs as well as TIMP-1, while duration of diabetes emerged as the strongest predictor of AD (P<.001). In the nondiabetic group, nonsignificant associations were also found between AD or augmentation index and MMPs as well as TIMP-1.'] Are plasma levels of MMP-2 , MMP-9 and TIMP-1 associated with arterial stiffness in subjects with type 2 diabetes mellitus?