Coadministration of Atorvastatin Prevents Nitroglycerin-Induced Endothelial Dysfunction and Nitrate Tolerance in Healthy Humans

Objectives We aimed to assess whether concurrent administration of atorvastatin would modify the development of tolerance and endothelial dysfunction associated with sustained nitroglycerin (GTN) therapy in humans. Background Animal studies have demonstrated that administration of 3-hydroxy-3 methylglutaryl coenzyme A reductase inhibitors can protect against GTN-induced endothelial dysfunction and tolerance, likely through an antioxidant mechanism. Methods Thirty-six healthy male volunteers were randomized to receive continuous transdermal GTN (0.6 mg/h) and placebo, atorvastatin (80 mg/day) alone, or continuous transdermal GTN (0.6 mg/h) with concurrent atorvastatin (80 mg/day), all for 7 days. On the second visit, forearm blood flow was measured with venous-occlusion strain gauge plethysmography in response to incremental infusions of acetylcholine (7.5, 15, and 30 μg/min). Acetylcholine infusions were coinfused first with saline, and repeated during the coinfusion of vitamin C (24 mg/min). Blood pressure responses to sublingual GTN (400 μg) were assessed on both visits. Results Acetylcholine responses in the GTN plus placebo group were significantly attenuated versus those in the GTN plus atorvastatin and atorvastatin groups (p l 0.01). Coinfusion of vitamin C completely restored acetylcholine responses in the GTN plus placebo group (p l 0.01 vs. saline coinfusion), but caused no change in either the atorvastatin or the GTN plus atorvastatin groups. Blood pressure responses to sublingual GTN did not significantly change between visits in subjects receiving GTN plus atorvastatin and atorvastatin alone, but were significantly blunted in the GTN plus placebo group (p l 0.05). Conclusions The present findings demonstrate, for the first time in humans, that atorvastatin prevents both GTN-induced endothelial dysfunction and nitrate tolerance, likely by counteracting the GTN-induced increase in oxidative stress.