For some individuals untreated sleep apnea worsens hypertension. The good news is sleep apnea treatment, such as CPAP, usually helps to eliminate sleep apnea and thus improve associated co-morbidities. But what predicts who will develop hypertension associated with apnea?
Recently, an investigation set out to do this. By analyzing a large cohort of individuals (1500 people), a research group identified the individuals with untreated sleep apnea that later developed hypertension. They then compared characteristics of these individuals (age, gender, etc.) with those who did not eventually develop hypertension. Sleep apnea-related factors were also included. During the initial sleep study, measures of apneas/hypopneas per hour (AHI) and oxygen saturation (how much oxygen is in the blood) were measured. Blood oxygen is reduced when apneas and breathing cessation occur, and therefore this measure is particularly important.
Results showed individuals who were older, had higher body mass index (BMI, which incorporates both height and weight), comorbidity (other disorders), lower daytime oxygen blood content, and lower blood oxygen content during sleep were found to be significant predictors of who would develop hypertension.
So what have we learned? Overall, those who seem to be in worse health in general are more likely to have sleep apnea associated with hypertension. This may not be particularly surprising, but it is important information. If you are somebody who is of advanced age and who has a high BMI, be aware that your blood pressure might be elevated in the absence of sleep apnea treatment. If you are worried, see your sleep physician to be sure your sleep apnea treatment is functioning optimally.
Source: Natsios, G., Pastaka, C., Vavougios, G., Zarogiannis, S. G., Tsolaki, V., Dimoulis, A., ... & Gourgoulianis, K. I. (2015). Age, Body Mass Index, and Daytime and Nocturnal Hypoxia as Predictors of Hypertension in Patients With Obstructive Sleep Apnea. The Journal of Clinical Hypertension.