Impaired responsiveness to NO in newly diagnosed patients with rheumatoid arthritis.

Cardiovascular disease is the major cause of excessive mortality in patients with rheumatoid arthritis (RA). We determined whether endothelial dysfunction characterizes patients with newly diagnosed RA (n=10) compared with normal subjects (control group, n=33) and whether it is reversible with 6 months of anti-inflammatory therapy. Endothelial function was determined by measuring vasodilatory responses to intrabrachial artery infusions of acetylcholine (ACh at 7.5 and 15 microg/min, low and high dose, respectively), an endothelium-dependent vasodilator, and to sodium nitroprusside (SNP, 3 and 10 micro g/min), an endothelium-independent vasodilator. Before treatment, blood flow responses (fold increase in flow) to low-dose SNP were 30% lower in the RA versus the control group (4.1+/-0.4-fold versus 5.9+/-0.5-fold, respectively), and responses to high-dose SNP were 34% lower in the RA group versus the control group (5.1+/-0.6-fold versus 7.7+/-0.7-fold, respectively; P<0.001). The responses to low-dose ACh were 50% lower in the RA group versus the control group (3.0+/-0.5-fold versus 6.6+/-0.7-fold, respectively), and responses to high-dose ACh were 37% lower in the RA group versus the control group (5.0+/-0.4-fold versus 7.9+/-0.8-fold, respectively; P<0.001). After therapy, clinical and laboratory markers of inflammation had significantly decreased. Blood flow responses to ACh increased significantly (P=0.02). We conclude that newly diagnosed patients with RA have vascular dysfunction, which is reversible with successful therapy. Therefore, early suppression of inflammatory activity may reduce long-term vascular damage.