The Surprising Symptom That Raises Stroke and Heart Attack Risk

Paying attention to a common, highly treatable, but often overlooked symptom could help doctors more easily identify people at increased risk for heart attacks and strokes, two new large studies suggest.
This symptom—frequent daytime drowsiness brought on by sleep problems—is so ubiquitous that many people don’t recognize it as a potential health threat that warrants discussion with their medical provider, says Amy Doneen, ARNP, medical director of the Heart Attack & Stroke Prevention Center in Spokane, WA.
The new research, just in time for National Stroke Awareness Month (May), could help solve a medical mystery: Why heart attacks and strokes frequently occur in people without conventional risk factors. Only about half of strokes can be explained by such well-established risks as smoking, high blood pressure, obesity, and diabetes, according to a new study published in PLOS Medicine 
That’s prompted intensive research into other potentially preventable factors that may boost  the risk of cardiovascular disease (CVD), such as insomnia and other sleep disorders. Here’s  a closer look at why you should take fatigue and trouble sleeping seriously—and what to do about it.

Insomnia Can Increase Stroke Risk by 8x

People with insomnia have a 54 percent higher risk for stroke, compared to those without this disorder, according to a study published in the American Heart Association journal Stroke.
Young people with this sleep problem were in far greater peril, with the researchers reporting that 18-to-34-year-old insomniacs were more than eight times more likely to suffer a stroke than people the same age who sleep normally.
The researchers tracked 21,438 initially healthy insomniacs and 64,314 non-insomniacs during a four-year period. The study is the first to report that trouble sleeping elevates stroke risk and also found that people with persistent insomnia face a greater threat than those who had been successfully treated for the condition.
“What our study adds to the field is that insomnia should also be considered as one of the risk factors of stroke, especially among young adults,” study author Ya-Wen Hsu, an assistant professor at Chia Nan University of Pharmacy and the department of medical research at Chi-Mei Medical Center in Taiwan, 

Daytime Drowsiness Linked to Higher Rates of Heart Disease

Women who frequently feel drowsy during the daytime have a 58 percent higher risk for CVD, the leading killer of Americans, compared to those who are rarely or never experience this symptom, according to an analysis published in the journal Sleep Medicine.
About 20 percent of adults suffer from chronic daytime sleepiness—inability to stay awake and alert during waking hours—resulting in dozing off or drowsiness. This symptom has been linked to cognitive impairment, car accidents, medical errors, and elevated heart disease risk in earlier studies.
The researchers analyzed data from 84,003 participants in the long-running Nurses’ Health Study. At the start of the study, the women were between the ages of 37 and 54. Participants were tracked for eight years, during which 500 cases of heart disease or stroke occurred.

Why Insomnia and Heart Problems Are Linked

Several previous studies have also found links between slumber problems and CVD danger. For example, a 2012 analysis pooled results from five prior studies with 8,435 participants and found that obstructive sleep apnea—a sleep disorder marked by loud snoring and interruptions in breathing—more than doubles stroke risk.
There are several key reasons why people who don't catch enough zzzs due to insomnia or sleep disorders are more likely to suffer heart attacks and strokes, explains James Gangrich, Ph.D., author of the Nurse’s Health Study analysis discussed above. These factors include:
  • Higher blood pressure. During normal sleep, blood pressure typically drops by 10 to 20 percent, compared to the level when you’re awake, says Gangrich. “Therefore, people who don’t get the normal amount of sleep—about seven to nine hours a night—have higher average blood pressure over a 24-hour period.” High blood pressure is the leading risk factor for stroke and one of the major risks for heart attack.
  • Insulin resistance (the disorder that leads to type 2 diabetes). “In sleep deprivation studies, previously healthy people have such a dramatic change in their insulin levels that they temporarily become pre-diabetic,” reports Doneen, coauthor of Beat the Heart Attack Gene. “Studies also suggest that insulin resistance is one of the culprits in up to 70 percent of heart attacks,” she reports.
  • Increases in hunger hormones. Skimping on shuteye has a powerful effect on levels of the appetite-regulating hormones ghrelin and leptin. “As a result, sleep-deprived people tend to crave sugary and salty snacks, both of which are high in calories,” notes Gangrich. That can lead to packing on excess pounds, which in turn is a risk factor for heart disease and diabetes (a disease that further increases risk for heart attacks and strokes).
  • Increased inflammation. Insufficient slumber can also contribute to arterial inflammation, upping the threat of both developing CVD in the first place and suffering cholesterol plaque ruptures that could trigger a heart attack or stroke, adds Doneen. 

What should you do if you can’t sleep?

Gangrich emphasizes that daytime drowsiness doesn’t cause heart attacks or strokes, but for a variety of reasons, is linked to other factors that may elevate risk, such as insufficient sleep, obesity, diabetes, high blood pressure, or high cholesterol.
While his study found that daytime fatigue is not an independent risk factor for heart disease, it concluded that, “Getting sufficient quality sleep on a regular basis may represent a lifestyle practice that contributes to the prevention of CVD.”
Both Gangrich and Doneen suggest consulting your medical provider if you have persistent insomnia, daytime fatigue or other sleep issues. In some cases, a sleep study may be recommended to help diagnose the problem.
Often simple lifestyle changes, such as getting more exercise, avoiding late night computer use, relaxing bedtime rituals, and having a regular sleep schedule, can help you get a better night’s rest.