The difference of pulmonary artery pressure between the groups was statistically significant: AHI < 5: 41, 2 ± 10, 1; 5≤AHI<15: 36, 2 ± 7, 5; 15≤AHI< 30: 38, 9 ± 9, 3; AHI ≥ 30: 75, 7 ± 21, 1; p< 0, 00.