- Insomnia may be linked to a higher risk of cardiovascular disease and stroke.
- About 30 percent of people in the United States exhibit some symptoms of insomnia.
- Experts say sleep provides the body with the recovery it needs.
- They say the best way to overcome insomnia is with cognitive behavioral therapy.
Insomnia is a problem worth losing sleep over.
Not only is it frustrating to toss and turn all night, but insomnia may also be bad for your cardiovascular health.
People with a genetic predisposition toward insomnia are at higher risk of coronary artery disease, heart failure, and stroke, according to a new study published in the American Heart Association journal Circulation.
Researchers, led by Susanna Larsson, PhD, an associate professor of cardiovascular and nutritional epidemiology at the Karolinska Institutet in Sweden, studied 1.3 million people with and without cardiovascular disease.
They used a research technique called Mendelian randomization to determine if people who carry a genetic variant known to be associated with insomnia were more at risk of heart and circulatory problems.
“Insomnia may lead to increased body weight, high blood pressure, and type 2 diabetes, all of which are risk factors for cardiovascular disease,” Dr. Larsson told Healthcare Website.
Researchers stressed, however, that the study only demonstrated an association between the two disorders, not a cause-and-effect relationship.
Also unclear is whether insomnia causes heart problems or vice versa, said Andrew Stiehm, MD, who specializes in pulmonary and sleep medicine at Allina Health’s United Sleep and Lung Center in St. Paul, Minnesota.
“It’s probably both,” Dr. Stiehm told Healthcare Website. “Insomnia does cause you to have higher blood pressure. But heart disease causes insomnia as well.”
Similarly, while insomnia is suspected of raising the risk of diabetes, the neuropathy associated with the disease can also cause limb pain that can disrupt sleep, Stiehm noted.
About 30 percent of the U.S. population has some symptoms of insomnia, which past studies have shown to be related to increased risk of type 2 diabetes and other health problems.
However, only about 10 percent of the population has a chronic insomnia disorder, according to the American Academy of Sleep Medicine (AASM).
Insomnia symptoms include:
- difficulty falling asleep
- difficulty staying asleep throughout the night
- waking up too early in the morning
Chronic insomnia is defined as occurring at least three times per week and lasting for at least three months.
“Chronic insomnia can be a severe detriment to physical, mental, and emotional health by negatively impacting daytime alertness, mood, memory, and cognitive function,” according to the AASM.
“In general, sleep is good for your body,” Joyce Oen-Hsiao, MD, a Yale Medicine cardiologist, told Healthcare Website. “It helps the body to relax and recover after a hard day. Being able to recharge your body can lead to improvement in metabolism and less stress, which can in turn lead to improved cardiac health.”
“There is an interesting connection between the sleep-wake cycle and cardiovascular regulation,” Deena Kuruvilla, MD, a Yale Medicine neurologist, told Healthcare Website.
“Studies show, for example, that non-rapid eye movement sleep decreases arterial blood pressure and heart rate and increases the parasympathetic function of the heart at specific points in the night. Insomnia may in turn affect circadian heart regulation and lead to cardiovascular disease and stroke,” she said.
The AASM says the most effective treatment for chronic insomnia is cognitive behavioral therapy.
This therapy combines behavioral strategies such as setting a consistent sleep schedule with cognitive strategies such as replacing fears about sleeplessness with more helpful expectations.
“The National Sleep Foundation states that we should be getting 7 to 9 hours of sleep on a nightly basis,” Bill Fish, a certified sleep coach, told Healthcare Website. “If you aren’t, you are probably also suffering some anxiety and frankly aren’t giving your heart the time it needs to be resting.”
“On the flip side,” he said, “insomnia can also be looked at as a ‘check engine light’ of sorts. If you are having difficulty getting to sleep on a nightly basis, and it isn’t normal for you, it may be your body telling you something. If this issue persists for over two weeks, it would be good to see your physician to talk through the issues.”
The Mendelian randomization design uses genetic variants associated with conditions like insomnia as “proxy indicators” to determine whether the risk factor causes the disease.
“Given that genetic variants are randomly assorted when passed from parent to offspring at conception, one trait… is not associated with another trait,” Larsson said. “Thus a Mendelian randomization study usually avoids confounding from other risk factors, similarly to a randomized controlled trial where participants have been randomly assigned to receive the treatment or not.”
The study design has its limitations, however, including the fact that study participants didn’t directly report whether they have insomnia or to what degree.
“We did not have information on self-reported insomnia among participants that developed or remained free of cardiovascular disease,” Larsson said.
“It’s not clear how we can really say for certain that there is a link between insomnia and any of the cardiac issues,” Dr. Oen-Hsiao said. “Basically, the study only showed that people who have that genetic variation in their DNA showed a tendency to have higher risk of heart disease, heart failure, and stroke.”
She continued: “It says nothing about people who just can’t sleep well. Just because you can’t sleep well doesn’t mean you will have a higher risk of coronary disease.”
Larsson said that “further research assessing whether treatment of insomnia, for example, through changes in lifestyle and behaviors or stress management, reduces the risk of cardiovascular disease [is needed].”