Several research studies have linked high blood pressure (HTN) to obstructive sleep apnea (OSA). The etiology is not clear, however. With OSA, there is sleep disturbance from brief awakenings, thought secondary to adrenaline release that is triggered when breathing resumes. Also, oxygen level reductions, called desaturations, could lead to elevated blood pressures. Respiratory events that are detected during a sleep study have specific scoring criteria - the event has to last at least 10 seconds and result in either a brief arousal from sleep and / or an oxygen desaturation.
This study sought to determine which types of respiratory events were most likely to result in HTN. The researchers followed 2040 participants and used sophisticated statistical models to study the sleep study results and blood pressure measurements. Results showed that those respiratory events with at least a 4% oxygen desaturation were most consistently associated with HTN. Interestingly, the other sleep study measurement that correlated with HTN was periodic limb movements that resulted in brief arousals from sleep.