Some studies have shown correlations between selected proinflammatory factors and carotid atherosclerosis. It has not been established whether anti-inflammatory cytokines are associated with carotid intima-media thickness (IMT), an ultrasound surrogate marker of atherosclerosis. Therefore, the authors studied the relationship between the carotid IMT and serum levels of interleukin (IL)-10 and transforming growth factor-beta1 in 76 subjects. They discovered that lower IL-10 levels were associated with increased mean IMT in common carotid arteries.