Throughout the month of February, affectionately known as American Heart Month, the News Blog highlights news and stories related to cardiovascular health from across Penn Medicine.
Countless studies have proven that a lack of sleep is detrimental to your health in numerous ways, but how do sleep problems affect the heart?
The connection is very strong in up to half of the 12 to 18 million U.S. adults with sleep apnea who are also heart disease patients.
There are two forms of sleep apnea – obstructive, when the airway closes while you are asleep, causing choking, and central sleep apnea, when the connection between the brain and the respiratory muscles is disrupted, leading to rapid breathing then long pauses. Both forms lead to significant stress on the heart and blood vessels.
“Each time there is a pause in breathing there is a surge of stress hormones like epinephrine causing blood pressure to go up, increasing the risk of irregular heart rhythm (both atrial fibrillation and ventricular tachycardia), heart attacks, strokes, and worsening heart failure,” said Lee R. Goldberg, MD, MPH, FACC, associate professor of medicine, and medical director of Penn Medicine’s Heart Failure and Cardiac Transplant Program. “There is also growing evidence that sleep apnea can make coronary disease worse over time and diabetes more difficult to control.”
This rapid increase in stress hormones and lower oxygen levels in the blood cause blood vessels to constrict, resulting in higher blood pressure during both sleep and wakefulness in sleep apnea patients.
Sleep apnea can happen at any age, with higher risk as one gets older. Being obese, having a family history of sleep apnea, and having a neck size greater than 17 inches can also raise your risk. Poor or reduced sleep is also associated with decreases in leptin, a neurohormone that tells the brain you are full after eating. This may contribute to the obesity noted in individuals with poor or reduced sleep, further complicating matters.
If you experience fatigue, morning headaches, snoring, falling asleep during the day, depression and noticed irregular breathing while sleeping, you may have sleep apnea.
Symptoms of sleep apnea can include some usual suspects – morning headaches or falling asleep during the day, for instance – but the body also sends out signals that people may find surprising - including fatigue, snoring, depression and irregular breathing while sleeping.
Cardiologists are increasingly interested in screening and treating sleep apnea to reduce these risks and the risk of death from cardiovascular disease. For example, current high blood pressure guidelines instruct doctors to consider sleep apnea when a person requires three or more medications to control their blood pressure.
Ilene Rosen, MD, MSCE, FAASM, program director of the Penn Sleep Fellowship and associate professor of clinical medicine, notes that, although insufficient sleep may not directly cause heart disease, significant studies show limited sleep increases risk factors for many heart problems.
“When you are experiencing good-quality sleep, your heart is more likely to perform as it is intended, with blood pressure and heart rate decreasing during the night,” Rosen said.
The Heart Failure Program and the Sleep Medicine Programs at Penn Medicine regularly partner in research and clinical care for sleep apnea patients.
For example, Goldberg and Penn Medicine colleagues, including Richard Schwab, MD, professor of Medicine, published a study in the Journal of Clinical Sleep Medicine last October that found another benefit to treating sleep apnea in cardiac patients: reducing 30-day hospital readmissions. The study showed that early, effective treatment with positive airway pressure therapy initiated at the time of admission reduced 30-day hospital readmission rates and emergency department visits in patients with cardiac disease and sleep apnea.
A clinical trial for sleep apnea patients is also currently underway at Penn that tests a special pacemaker that can stimulate the nerves in the chest that control breathing to prevent pauses in breathing at night. This may be a strong alternative to wearing a mask in order to receive positive airway pressure at night to treat central sleep apnea. Other options for patients with sleep-disordered breathing include devices worn inside the mouth, losing weight, and surgery to the upper airway.
“Sleep is critical to our health—and the heart is central to that,” Rosen said.
Photo above: Collapsed airway in sleep apnea patient from Midway via flickr.