PCSK9 and sleep apnea syndrome: Previous studies have found that patients with sleep apnea have significantly increased PCSK9 levels and larger plasma low-density lipoprotein diameters after statin use.[8] According to Sanja Jelic, statins may be 1 way to improve the health of people with sleep apnea.[41] The study found that statins, but not CPAP (continuous positive airway pressure), protected blood vessels from dangerous inflammatory changes that occur in patients with sleep apnea.