Supplemental oxygen eliminates the rise in morning blood pressure experienced by obstructive sleep apnea patients who stop using continuous positive airway pressure (CPAP), the standard treatment for OSA, according to new research published online in the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine.

Many studies have demonstrated an association between OSA, hypertension and cardiovascular disease. Some of these studies have linked the acute rises in blood pressure that OSA patients experience while sleeping to the constant need to wake up when their breathing stops or is partially blocked.
reference: https://www.news-medical.net/news/20180720/Study-Supplemental-oxygen-prevents-rise-in-morning-blood-pressure-in-OSA-patients.aspx