[Three month continuous positive airway pressure (CPAP) therapy decreases serum total and LDL cholesterol, but not homocysteine and leptin concentration in patients with obstructive sleep apnea syndrome (OSAS)].

Introduction: In OSAS patients CPAP therapy decreases cardiovascular morbidity and mortality. Homocysteine and leptin may play a role in development of ischaemic heart disease (IHD) in patients with OSAS. The aim of the study was to assess the influence of 3 month CPAP therapy on cardiovascular risk factors in patients with OSAS without IHD (pure OSAS) and with OSAS and IHD.
Material and Methods: Therapy with CPAP was started in 42 OSAS without IHD (pure OSAS) and 23 OSAS and IHD patients. Plasma concentration of homocysteine, serum concentration of leptin, C-reactive protein (CRP), fibrinogen, lipids, and markers of visceral adiposity (MVA) were measured before and after treatment.
Results: There were no significant changes in homocysteine, leptin, fibrinogen and CRP concentrations in neither group. In OSAS and IHD no change in serum lipids and MVA were found. In pure OSAS group total cholesterol and LDL cholesterol concentrations significantly decreased (202.5 ± 38.5 mg/dl v. 186.7 ± 33.5 mg/dl, p = 0.001 and 127.3 ± 32.9 mg/dl v. 116.4 ± 26.9 mg/dl, p = 0.02, respectively). Triglycerides did not significantly change (p = 0.09). There were no significant changes in BMI (30.4 ± 3.8 v. 30.6 ± 3.6, p = 0.5), waist circumference (108.5 ± 8.0 cm v. 107.0 ± 7.5 cm, p = 0.09) and waist to hip ratio (1.03 ± 0.04 v. 1.01 ± 0.03, p = 0.07).
Conclusions: Three month CPAP therapy did not change homocysteine and leptin concentration in neither group. However, it significantly decreased serum lipids concentration in patients with pure OSAS, but not in patients with OSAS and IHD, suggesting beneficial effects of CPAP therapy on cardiovascular risk factors.