Regular use of cocaine raises the risk of developing circulatory problems, which begin with dysfunction of endothelial cells and can progress to heart disease (premature atherosclerosis and to dangerous narrowing of the coronary artery). The protein endothelin-1 (ET-1) is associated with endothelial dysfunction, and previous work has shown that levels of ET-1 change with cocaine use: ET-1 is higher in cocaine users than in those who don’t use cocaine, and abstinence from cocaine can bring levels of ET-1 down. This flexibility raises the possibility that ET-1 could function as a biomarker for cocaine use and for cocaine-induced risk of heart disease.
This study examined ET-1 levels and coronary plaques in a group of African American cocaine users participating in an incentive-based program to reduce cocaine use. In addition to confirming the finding that abstinence from cocaine lowers ET-1, the study found that more mild reductions in cocaine use also lowered levels of ET-1. This change in ET-1 provides evidence that both total abstinence and reduction in cocaine use could protect against endothelial dysfunction. Additionally, the responsiveness of ET-1 to changes in cocaine use could make it a useful biomarker to measure harm-reduction outcomes when developing treatments for cocaine use disorder.