Relationships among Renal Function Loss within the Normal to Mildly Impaired Range, Arterial Stiffness, Inflammation, and Oxidative Stress

BACKGROUND AND OBJECTIVES: This study was conducted to clarify whether individuals with mildly impaired renal function show increased arterial stiffness, microinflammation, and oxidative stress as compared with those with normal renal function and also to examine the association of these parameters with the degree of GFR loss in middle-aged Japanese men with a low cardiovascular risk. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: The brachial-ankle pulse wave velocity and plasma levels of C-reactive protein and lipid peroxides were measured in 1873 men (42 +/- 9 yr of age). RESULTS: The brachial-ankle pulse wave velocity but not the plasma C-reactive protein or lipid peroxides, was increased in individuals with mildly impaired renal function. The GFR was significantly correlated with the brachial-ankle pulse wave velocity but not with the log-transformed values of C-reactive protein or lipid peroxides. Multivariate linear regression analysis demonstrated a significant relationship between the brachial-ankle pulse wave velocity and the GFR, independent of the conventional atherosclerotic risk factors. This relationship was significant even in individuals with GFR values within the "normal renal function" range. Thus, GFR loss seems to be more closely associated with arterial stiffness than with microinflammation and/or oxidative stress. CONCLUSIONS: A weak but significant relationship was observed between the degree of GFR loss and arterial stiffness, even in individuals with GFR values within the normal renal function range. Therefore, increased arterial stiffness may underlie, at least in part, the elevated cardiovascular risk in individuals with mildly impaired renal function.