The L-arginine/asymmetric dimethylarginine ratio is improved by anti-Tumor Necrosis Factor-α therapy in inflammatory arthropathies. Associations with aortic stiffness

Background: Anti-Tumor Necrosis Factor (TNF)-alpha therapy improves vascular pathology in inflammatory arthropathies such as rheumatoid arthritis, ankylosing spondylitis and psoriatic arthritis. The L-arginine/ADMA ratio is important for modulation of the nitric oxide synthase activity. We examined the effect of TNF-alpha antagonists on ADMA and L-arginine/ADMA, and associations between ADMA, L-arginine/ADMA, aortic stiffness and carotid intima media thickness (CIMT) in patients with inflammatory arthropathies. Methods: Forty-eight patients who started with anti-TNF-alpha therapy were compared with a non-treated group of 32 patients. Plasma ADMA and L-arginine were assessed at baseline, 3 and 12 months. In a subgroup of 55 patients, aortic pulse wave velocity (aPWV) was measured at baseline, 3 and 12 moths, and CIMT was examined at baseline and 12 months. Results: Anti-TNF-alpha therapy increased the L-arginine/ADMA ratio (mean [SD]) in the treatment group compared to the control group after 3 months (12 [29] vs. - 13 [20], P < 0.001) and 12 months (7 [27] vs. - 8 [19], P = 0.008), but did not affect ADMA (3 months: 0.00 [0.09] mu mol/L vs. 0.02 [0.07] mu mol/L, P = 0.42, 12 months: 0.01 [0.08] mu mol/L vs. 0.01 [0.09] mu mol/L, P = 0.88). Baseline aPWV was associated with ADMA (P = 0.02) and L-arginine/ADMA (P = 0.02) in multiple regression analyses, and the L-arginine/ ADMA ratio was continuously associated with aPWV after initiation of anti-TNF-alpha therapy (P = 0.03). ADMA and L-arginine/ADMA were not correlated with CIMT. Conclusion: Anti-TNF-alpha therapy improved the L-arginine/ADMA ratio in patients with inflammatory arthropathies. ADMA and the L-arginine/ADMA ratio were associated with aPWV, and might have a mechanistic role in the aortic stiffening observed in these patients. (C) 2012 Elsevier Ireland Ltd. All rights reserved.