Phillips et al randomized and serially drew 7 blood samples (day and night) on 29 people with obstructive sleep apnea who were wearing either continuous positive airway pressure or sham CPAP. It was a crossover design (patients were their own controls). CPAP reduced the total area-under-the-curve for triglyceride concentration and mean 24-hour cholesterol. This provides a partial mechanism for how CPAP might attenuate cardiovascular risk in people with OSA. AJRCCM 2011;184:288-290.