Objectives: Because the endothelium is a major target for inflammatory cytokines, we investigated whether elevated interleukin (IL)-10 serum levels are associated with improved endothelial vasoreactivity in patients with coronary artery disease (CAD).
Background: Chronic inflammation plays a pivotal role in the progression of atherosclerosis. Interleukin-10 is an anti-inflammatory cytokine that exerts important protective effects on atherosclerotic lesion development in experimental animals.
Methods: Vasoreactivity was assessed in 65 male patients with documented CAD by measuring endothelium-dependent (acetylcholine [ACh] 10 to 50 microg/min) and endothelium-independent (sodium nitroprusside [SNP] 2 to 8 microg/min) forearm blood flow (FBF) responses using venous occlusion plethysmography.
Results: Serum levels of IL-10 were significantly correlated with ACh-induced FBF responses (r = 0.31, p < 0.02), but not with SNP responses. Importantly, if IL-10 serum levels were increased in patients with elevated C-reactive protein (CRP) levels, no impairment of ACh-stimulated FBF response was observed. On multivariate analysis, including low-density lipoprotein cholesterol, smoking, hypertension, diabetes, clinical status of the patients, and statin and/or angiotensin-converting enzyme inhibitor treatment, only IL-10 (p < 0.02) and CRP serum levels (p < 0.02) were significant independent predictors of ACh-induced FBF responses.
Conclusions: Thus, increased IL-10 serum levels are associated with improved systemic endothelial vasoreactivity in patients with elevated CRP serum levels, demonstrating that the balance between pro- and anti-inflammatory mediators is a major determinant of endothelial function in patients with CAD.