Assessment of endothelial function as a marker of cardiovascular risk in patients with rheumatoid arthritis.

The endothelium is a major regulator of cardiovascular function and maintains an atheroprotective role through several mechanisms, including vasodilatation, inhibition of platelet aggregation, having anticoagulant and profibrinolytic effects, and having an anti-inflammatory effect. Early changes in the normal functioning of the endothelium are key initiating factors in the development and progression of atherosclerosis. These changes are present well before the presentation of clinical symptoms. Thus, researchers have focused much attention on developing methods for reliable non-invasive testing of endothelial function to allow early detection and monitoring and progression of subclinical atherosclerosis. To date, there is a wide range of methods in use to assess endothelial function, each with its own advantages and limitations. Ideally, the tests should be non-invasive to allow repeated measurements and be applicable in normal healthy subjects and also in children. Given the wide range of regulatory functions of the endothelium, it is not surprising that there is no single measure of endothelial function that provides all the necessary information regarding vascular integrity in different vascular beds. Therefore, a combination of tests examining different components of the vascular system is more appropriate. Since patients with rheumatoid arthritis have increased mortality due to cardiovascular disease, assessment of endothelial function could prove to be useful tools in the identification and monitoring of cardiovascular risk. The purpose of this review is to give a brief overview of some of the commonly used techniques for assessment of endothelial function, and in particular on those that have been used in studies of patients with rheumatoid arthritis.