Despite being an athlete in college, Kevin put on some weight over the years as the realities of long work weeks and raising three kids with his wife took their toll. During an annual check-up six months ago, he was told he had high blood pressure (hypertension) and placed on medication to lower it. Over the next several months, various dosages and medications were tried, but Kevin’s blood pressure continued to remain high.
While talking over lunch, a coworker mentioned that he had recently been diagnosed with Obstructive Sleep Apnea (OSA) and was using a Continuous Positive Airway Pressure (CPAP) machine to sleep more soundly at night. He noted that it had reduced his blood pressure to the point where his doctor was able to lower the dosage on his medication. Kevin’s friend encouraged him to see a sleep specialist and find out if untreated sleep apnea might be contributing to his difficulties getting his blood pressure under control.
Sleep Apnea and the “Silent Killer”
More than 18 million American adults are estimated to have sleep apnea, and it’s estimated that two to three percent of children do as well. Sleep apnea is a condition that occurs when the airway becomes blocked by relaxed tissue as the brain enters a state of sleep. This blockage prevents air from moving—essentially stopping a person’s breathing and causing their oxygen levels to drop. In response to these decreases, the brain will trigger arousals from sleep to reopen the airway. While these arousals often occur on a subconscious and barely noticeable level, they can occasionally be strong enough to produce snorts or gasps during sleep. Once the airway is reopened, the brain goes back to sleep, the tissues relax, the airway becomes blocked, and breathing is stopped again until the next arousal. This process is repeated many times throughout the night and produces the daytime tiredness and fatigue often associated with sleep apnea. It also places a strain on the body’s cardiovascular system—so perhaps it’s not surprising there’s a significant link between sleep apnea and hypertension. It’s estimated that 40% of people with untreated sleep apnea will develop hypertension, and 30% of all hypertension patients have sleep apnea—and most are not even aware of it!
Unlike sleep apnea—whose symptoms are often apparent—hypertension usually does not cause any symptoms until an event such as a stroke occurs. “This is why it is often referred to as the ‘silent killer’”, explains Dr. Susan Borchers, board-certified pulmonologist, sleep specialist and medical director of the sleep lab for OhioHealth Sleep Services of Worthington. Because of this, “all patients with sleep apnea should be monitored for hypertension, and most patients with hypertension should at least be screened (i.e., sleep questionnaire, consultation, or sleep study) for sleep apnea.”
Continuous Positive Airway Pressure (CPAP): An Effective Treatment
Primary hypertension affects approximately 72 million Americans. For most, medications can be used to adequately control their blood pressure. However, for people who have sleep apnea and hypertension, their blood pressure is often resistant to medications. The American Heart Association defines “resistant hypertension” as blood pressure that remains high despite the use of three medications from different classes. A 2001 study found that patients with resistant hypertension had more severe sleep apnea than those whose morning and evening blood pressures were normal. “One of the more common reasons for a sleep consultation,” notes Dr. Borchers, “is for a patient with resistant hypertension requiring multiple medications.”
The standard treatment for sleep apnea is Continuous Positive Airway Pressure (CPAP), which involves wearing a small mask while asleep through which air is delivered. The air is generated at a set pressure by a small machine and functions to prevent the airway from collapsing when the brain goes to sleep and the tissues relax. With the airway held open by this pressure support, normal breathing is maintained and the brain is able to achieve a much higher quality of rest—which leads to increased energy and feeling more refreshed when waking up the next day.
For people with sleep apnea and resistant hypertension, CPAP therapy has an added benefit: studies have shown significant reductions in both daytime and nighttime blood pressure after only two months of regular CPAP use. “If they have severe obstructive sleep apnea, their blood pressure really does respond to treating them with CPAP,” says Dr. Borchers.
Kevin took his friend’s advice and saw a sleep specialist, who diagnosed him with moderate to severe sleep apnea after a sleep study was performed. A CPAP titration was done to find an effective pressure setting, and Kevin was set up with a CPAP mask and machine to use at home each night. “It took me a couple of weeks to get adjusted to wearing it each night,” he says. “But once I got used to it, it’s been great—I feel more energetic when I wake up in the morning. Best of all, my blood pressure finally came back down as well!”