Left ventricular (LV) diastolic dysfunction and increased arterial stiffness are prevalent in patients with type 2 diabetes mellitus (DM). Because the systemic vasculature plays a pivotal role in myocardial loading, this study aimed to determine the effect of arterial characteristics on LV diastolic function in patients with type 2 DM. Conventional echocardiography and tissue Doppler imaging were performed in 155 patients with type 2 DM (88 men; mean age 55 +/- 11 years) with preserved LV ejection fractions (>50%). Patients were stratified into groups on the basis of LV diastolic function (normal, n = 53; delayed relaxation, n = 79; pseudonormal, n = 23). Arterial wave reflection parameters and central blood pressure were determined by radial tonometry. Arterial (brachial and carotid) structure and function were determined by standard ultrasound methods. There were no significant differences among the groups on central pressure or arterial function. LV filling pressure, determined by the ratio of early transmitral inflow velocity to diastolic early tissue velocity (E/E'), was significantly correlated with central pulse pressure (r = 0.21, p <0.05). Late diastolic inflow velocity (A) was significantly associated with central pulse pressure (r = 0.32, p <0.001), total arterial compliance (r = -0.35, p <0.001), and carotid artery stiffness (r = 0.34, p <0.001). Multiple regression analysis found central but not brachial pulse pressure independently predicted E/E' and A. In conclusion, increased central pulse pressure, possibly due to amplified pressure wave reflections, is independently associated with abnormal LV diastolic function in patients with type 2 DM.