Abstract

Background: Obstructive Sleep Apnoea (OSA) is a common nocturnal respiratory disorder and its role as a risk factor for the development of Pulmonary Hypertension (PH) is well known. It was already demonstrated that systolic pulmonary artery pressure (PAPs) in obese patients with OSA is higher than in obese patients without OSA (Carratù P. et al, Sleep Breath 2016; 20: 613-619).

Aims: to evaluate correlations between nocturnal cardiorespiratory indices, as Apnoea-Hypopnea Index (AHI), Oxygen Desaturation Index (ODI) and Total Sleep Time with oxyhemoglobin saturation below 90% (TST90), and PAPs in obese patients affected by OSA.

Methods: We studied 48 consecutive patients affected by OSA, defined according to AASM guideline (Berry RB et al, J Clin Sleep Med 2012; 8 (5): 597-619). Nocturnal Respiratory failure is defined as TST90 = 30%. Eight patients were excluded due to the presence of Overlap Syndrome OSA-Chronic Obstructive Pulmonary Disease (COPD). We evaluated linear correlation between hypnological parameters (AHI, ODI and TST90) and PAPs. Statistical significance: P <0.05.

Results: We demonstrated that there is no correlation between severity of OSA and PAPs. Comparing AHI and ODI with PAPs, statistical significance was not obtained (respectively P: 0.20; P: 0.33). A significant direct correlation was found only between PAPs and TST90 (P: 0.03).

Conclusions: Nocturnal respiratory failure could be the real determining factor for pulmonary hypertension in patients with OSA, but these preliminary results need further studies on a bigger sample to be confirmed.