This double-blind placebo-controlled parallel group randomized study design will be used to test whether 4 weeks of atorvastatin 10 mg daily reduces levels of inflammatory markers in OSA patients treated with CPAP (standard of care). The purpose of this study is to investigate: 1) whether statins reduce endothelial inflammation and pro-thrombotic conditions in OSA, including in patients adherent to CPAP (Aim 1); and 2) whether statins reduce endothelial inflammation and pro-thrombotic conditions by improving endothelial cholesterol metabolism and trafficking in OSA (Aim 2).