The Sleep Heart Health Study (6000 patients) and a study from European Respiratory Journal (366 patients) showed an association between severity of OSA and an increase in lipid profile (cholesterol). After treating patients with CPAP for months, a modest increase (5.8%) of HDL (good cholesterol) was observed. All patients with abnormal lipid levels improved significantly under CPAP therapy.
Borgel et al. Eur Respir J 2006; 27:121-127