Pulmonary hypertension in obstructive sleep apnea hypopnea syndrome

There has been uncertainty until recently whether OSA, is sufficient to cause persistent daytime pulmonary hypertension and right ventricular dysfunction. The aims of this study, were to investigate whether OSA by itself without any other cardiac or lung disease can lead to pulmonary hypertension, and to assess the effect of CPAP therapy on pulmonary artery pressure. The study was performed on 54 OSA patients. All patients were subjected to thorough history taking including Epworth sleepiness scale and Berlin questionnaire, physical examinations, calculation of BMI, plain chest X-ray pulmonary function tests, polysomnography and echocardiography. Ten patients out of 24 patients of OSA with PH have been treated with CPAP for six months. Pulmonary hypertension (PH) was present in (44.4%) of OSA patients. There were significantly higher PASP and mPAP in severe OSA patients versus non severe OSA patients. There were significant higher BMI, neck circumference, AHI and ODI in OSA patients with PH compared to OSA patients without PH. Awake SaO2 and minimum SaO2 were significantly lower in OSA patients with PH compared to OSA patients without PH. There were significant reduction in both mPAP and PASP after 6months of CPAP treatment (p=0.007, 0.005 respectively). OSA is associated with pulmonary hypertension, improvement of pulmonary hypertension through controlling OSA by CPAP therapy signifies that OSA plays a crucial role in the pathogenesis of pulmonary hypertension. CPAP therapy should be advised to all OSA patients with pulmonary hypertension.