Features January 2012 Issue

Insomnia and Other Sleep Troubles May Raise Your Heart Attack Risk

Poor sleep is a common condition in older adults, but new research suggests that it is especially of concern among heart patients.

If you have trouble sleeping at night, you could be facing a threat greater than fatigue the next day. Recent research suggests that insomnia is associated with an elevated risk of heart attack.

A study in the Oct. 25, 2011 issue of Circulation: Journal of the American Heart Association, found that the risk of heart attack in people with insomnia ranged from 27 percent to 45 percent greater than for people who rarely experienced trouble sleeping. Insomnia was characterized in the study in three different ways: Having trouble falling asleep almost every night (45 percent higher heart attack risk); having problems staying asleep almost every night (30 percent higher risk); and not waking up feeling refreshed in the morning more than once a week (27 percent higher risk).

Leslie Cho, MD, section head of Preventive Cardiology and Rehabilitation at Cleveland Clinic, says this latest study reaffirms research that continues to stress the importance of quality sleep in maintaining heart health. “There are increasing data that lack of sleep and heart disease risk may go hand in hand,” she says. “Lack of sleep increases blood pressure, increases weight, etc., so there is an interesting correlation.”

But insomnia is only one sleep-related problem that can contribute to cardiovascular disease. Dr. Cho notes, for example, that researchers in this sleep study did not adjust their findings for sleep apnea, a common condition that is considered a risk factor for heart disease. Sleep apnea is a condition in which individuals pause in their breathing many times throughout the night, often caused by a relaxation of tissue in the back of the throat that restricts the flow of air during respiration. Sleep apnea can contribute to hypertension, atherosclerosis and even cognitive dysfunction resulting from the frequent interruption or reduction of oxygen-rich blood reaching brain tissue throughout the night.

Dr. Cho also points out that researchers didn’t adjust for depression, which can often be the cause of insomnia and a condition related to heart disease.

If you Suspect Insomnia
Insomnia is generally defined as difficulty falling asleep or difficulty staying asleep or falling back to sleep if you awaken during the night. It can episodic, meaning nights with insomnia can come and go, or it can be short-term, in which insomnia symptoms last for up to three weeks. Chronic insomnia is considered to be an almost nightly problem.

“Insomnia is a spectrum,” says Douglas Moul, MD, with the Cleveland Clinic Sleep Disorders Center.  “The diagnosis of primary insomnia is derived from professional consensus (at least a month, etc.), and not from especially compelling epidemiological facts about the number of nights one has difficulty sleeping.”

In general, if your sleep troubles at night occur frequently enough for you to be aware of them and experience anxiety about going to bed, you should consult your doctor about the problem. If you often find yourself feeling sleepy during the day or you consistently wake up not feeling refreshed or well-rested, a supervised sleep study may be in order. Your doctor can order a sleep study, which will track your sleeping patterns during the night and identify problems such as sleep apnea.

As we age, we tend to sleep fewer total hours and spend less time in the deepest sleep stage, known as N3 (see chart), than we did when we were younger. These factors by themselves don’t equate to insomnia.

“Most people who think they have insomnia do not,” Dr. Cho says.  “They need to be screened.  If they really have insomnia, they should first initiate good sleep hygiene. If after you improve your nighttime routine you still can’t sleep, then go see your doctor. It may be that some people have a medical reason why they can’t get good sleep, such as sleep apnea, that needs formal diagnosis or treatment.”

Other Sleep Challenges
Many factors can contribute to insomnia and other sleep problems. Chronic pain can make it difficult to find a comfortable position in which to sleep, and many medications can interfere with sleep.

Dr. Moul even suggests that stress related to your difficulties with sleeping may exacerbate the problem. If you’ve ever gone to bed anxious about whether you will be able to fall asleep, you can understand why. Stress, caused by any number of factors, can contribute to high blood pressure and heart disease.

“No one has the definitive data to say pure insomnia, absent any other contributing causes, does have any effect on the heart,” Dr. Moul says. “It might, conceivably.  But if it does, it is not on the same scale with other medical problems.  It seems more likely that tension and worry about insomnia might be a cause of cardiac problems, by virtue of the added physiological stress accompanying worry.”  He adds that sleep worries may explain why medications such as benzodiazepines, which also include anti-anxiety benefits, might be protective, “not against the insomnia as such, but against the worry about insomnia.”

Nighttime Waking
Just as falling asleep can be difficult for many people, so too can staying asleep. And while people with sleep apnea often don’t full awaken during the night, people with other conditions can find themselves awake throughout the night. If you have heart failure, for example, and experience fluid buildup in your legs during the day, lying down at night may lead to more frequent urination as that fluid becomes absorbed by the kidneys.

Dr. Moul explains that waking up periodically during the night is entirely common and not necessarily a major health risk.

“It is entirely normal for good sleepers to wake up in the middle of the night, possibly with some frequency,” he says. “There is some opinion out there that the problem with insomnia, given the normality of awakenings, is not with awakenings as such, but of being able to go or return to sleep.”

Falling back to sleep typically requires the same approach you take to fall asleep in the first place: Keep your room dark and cool, and if you can’t fall back to sleep in 10 to 15 minutes, get out of bed and sit quietly in another room reading a book or doing something that is calming. Dr. Moul also suggests taking the steps to control the factors that may interfere with sleep.

“Do not ignore your other medical problems,” he says. “They may have effects on your sleep. For example, address pain as best as you can with your doctor’s diagnosis and treatments.

“After you make choices about what your are going to do with your sleep, then make evaluations about your choices only over time periods like a month at a time.  Keep to a pattern rather than changing things from day to day.  Better to check out actual changes month to month.  After making a choice, then don’t worry about it or micromanage it.  The worry and fussing will just get in the way of getting as good sleep as you can get. And don’t watch the clock at night.”