Urinary Albumin Excretion Is Increased in Patients with Rheumatoid Arthritis and Associated with Arterial Stiffness

Objective. Rheumatoid arthritis (RA) is associated with increased risk of cardiovascular disease (CVD). High urinary albumin excretion is a risk factor for CVD in the general population, but its role in atherosclerosis in patients with RA is not well defined. Methods. We determined the urine albumin to creatinine ratio (UACR) in 136 patients with RA and 79 controls. Individuals with diabetes or a clinical history of CVD were excluded. We measured coronary artery calcium (CAC) with electron beam computer tomography and augmentation index (AIx) using pulse wave analysis. In patients with RA, erythrocyte sedimentation rate and concentrations of vascular cell adhesion protein-1 (VCAM-1), interleukin 10 (IL-10), C-reactive protein, IL-6, tumor necrosis factor-alpha, and cystatin-C were measured and results correlated with UACR. Results. Patients with RA had higher UACR [median (interquartile range): 7.6 (4.0-15.5) mg/g] than control subjects: 5.6 (3.3-9.0) mg/g; p = 0.02. The presence of CAC was not associated with UACR in RA or control subjects. In patients with RA, UACR was significantly correlated with AIx (rho = 0.24, p = 0.01), higher levels of VCAM-1 (rho = 0.2, p = 0.01), and lower levels of IL-10 (rho = -0.2, p = 0.02). The association between AIx and higher UACR remained significant in multivariate analysis [beta coefficient of 1.5 (95% CI 0.1-2.8), p = 0.03 that adjusted for age, sex, and race]. Conclusion. Urinary albumin excretion was higher in patients with RA than controls and correlated with increased arterial stiffness, higher VCAM-1, and lower IL-10 concentrations.