Study suggests hypoxia is the main cause of BP rise in sleep apnea

Patients who had previously used continuous positive airway pressure (CPAP) for the treatment of sleep apnea, found that it helped to eliminate their morning blood pressure elevations. It also substantially reduced hypoxia. In a recent study in the American Journal of Respiratory and Critical Care Medicine, relative to treatment with supplemental air, pure oxygen was associated with a 6.6 mm Hg decrease in systolic and 4.6 mm Hg decrease in diastolic pressure.

What is the connection?

Obstructive sleep apnea has been known as a risk factor for hypertension and cardiovascular disease. However, it was not clear if that risk was associated with recurrent arousal or intermittent hypoxia, according to the study.

Understanding that supplemental oxygen reduced intermittent hypoxia but had only a minor effect on markers of arousal, makes a strong case for intermittent hypoxia being the dominant cause of daytime BP increases in patients with sleep apnea.

This study shows us that by blunting the dips in oxygen levels, the use of oxygen can have a positive effect on a person’s BP. We can start to look at patients with sleep apnea who have experienced high blood pressure that is not adequately treated with hypertension medication. According to this study, that specific group of patients should benefit from the use of oxygen therapy.

Oxygen improves BP

In this double-blinded study, CPAP was withdrawn for 14 nights during each treatment arm. During this time, participants received supplemental oxygen or regular air overnight through a face mask. The primary outcome was the change in home morning BP following the withdrawal of CPAP. Secondary outcomes included oxygen desaturation index, apnea hypopnea index, and subjective and objective sleepiness.

The use of supplemental oxygen significantly improved measures of intermittent hypoxia. There was also a significant reduction in heart rate rises index. While additional studies are needed to determine the best candidates for supplemental oxygen therapy, it is important to note these findings.

We, as dentists, can continue to treat sleep apnea patients with oral appliance therapy, but we should be mindful to other treatment options and what a sleep physician suggests for the best outcomes.

Even minor sleep problems can raise a woman’s BP

Here we go again. Even the smallest sleep disturbance can increase a woman’s risk of high blood pressure. This isn’t good. Women who slept for the recommended duration also experienced this increase. The key is eliminating any sleep disturbances altogether.

We know that insufficient sleep increases blood pressure, which leads to a risk for heart-related conditions. However, researchers recently completed a study that assessed whether or not less serious sleep issues could also cause measurable cardiovascular effects. What they found was, yes, it can.

Women are affected the most

About one-third of people in the U.S. do not get enough sleep with women affected more than men. Women are often more likely to be carers for children and elderly relatives, which accounts for their lack of sleep. They can also experience shifts in hormones both monthly and across their lifespan.

Because of this, researchers looked to focus on women in this new study. What they found was particularly worrisome because sleep deprivation and milder sleep problems may have a disproportionate effect on cardiovascular health in women.

As dental sleep medicine specialists, we need to help care for not only all our patients, but women in particular due to their increased chances of a lack of consistent sleep.