Association of Renal Resistive Index with Markers of Extrarenal Vascular Changes in Patients with Systemic Lupus Erythematosus

Recent data suggest that renal hemodynamic parameters obtained by duplex Doppler sonography, especially the intrarenal resistive index (RRI), may be associated with systemic vascular changes. We evaluated the relationships between RRI and arterial stiffness, assessed by aortic pulse wave velocity, and between RRI and subclinical atherosclerosis, assessed by measuring carotid intima-media thickness in patients with systemic lupus erythematosus. We enrolled 39 patients with systemic lupus erythematosus (mean age 39 y) compared with 19 healthy controls, matched for age and sex. Each participant underwent 24 h of ambulatory blood pressure, aortic pulse wave velocity, carotid intima-media thickness and RRI measurements. RRI correlated significantly with aortic pulse wave velocity (r = 0.44, p = 0.006), and with carotid intima-media thickness (r = 0.46, p = 0.003). Both correlations held (p = 0.01), even after correction for age, mean arterial pressure and glomerular filtration rate. Our results suggest that the RRI may be considered a marker of systemic vascular changes and probably a predictor of cardiovascular risk in patients with systemic lupus erythematosus.