Even people who have relatively little trouble with asthma during the day can have major difficulties at night. The reason: the body's 24-hour, or circadian, cycle. "In people with normal lungs, lung function falls during sleep--but only by about 8 percent, so it isn't a problem," says Dr. Martin. "But in asthmatics, lung function can fall by as much as 50 percent during sleep--with dire consequences. "
In addition, certain natural hormones that reduce inflammation and promote airway openness--like epinephrine (adrenaline) and cortisol--reach their lowest levels in the middle of the night. Meanwhile, other hormones that narrow the airways and promote mucous production, like histamine, increase at night.
Other biological and environmental factors contribute to making nighttime a nightmare for asthmatics: allergens, body positions, even undiagnosed sinusitis. How to counteract these factors? Based on interviews with leading asthma researchers, here are the key steps to help you get a good night's sleep.
See the right doctor. If you suspect nocturnal asthma, consult an asthma specialist. A diagnosis is necessary for effective treatment. "We have a saying: `All that wheezes is not asthma,'" says Dr. Martin. "Many types of lung disease, from congestive heart failure to emphysema, can get worse at night. " Whether you have asthma or not, you'll probably need a complete round of allergy tests. People with asthma are particularly allergy-prone, and allergens can cause nighttime wheezing. "Who wants to start taking asthma medications for the rest of his life, if he's really wheezing because of the cat or the pillow or something else that's easy to correct? " says Thomas Platts-Mills, M.D., head of the Asthma and Allergic Diseases Center at the University of Virginia.
Clean your bedroom. If your allergy tests come up clean, you can skip this suggestion and the next one. But if allergies are contributing to nighttime wheezing, you may have to do some cleaning and redecorating.
Dust mites are a common bedroom allergen. These microscopic relatives of spiders live in mattresses, Pillows, even carpeting. Plastic covers for your pillows and mattresses, and regular washing of bedclothes in hot water can keep them to a minimum. If feathers are your problem, you'll have to trade your feather pillow or down comforter for a hypoallergenic one. Removing carpets in favor of washable wood or vinyl floors can help, as can regular vacuuming and dusting. And if pet dander's the problem, banish Fido or Fluffy from the bedroom.
For some asthmatics, the nighttime poltergeist is pollen, says Dr. Platts-Mills. "Patients who are hot and bothered with hay fever and want fresh air often put fans in their windows. That blow, more pollen into the room, and then they may even end up in the hospital." A shut window and an air cleaner is a better approach.
But you'll still have to be meticulous about cleanliness, says Dr. Platts-Mills. "We think a HEPA (high-efficiency particulate air) filter can be useful in the bedroom, but it won't be useful if you have your head on a pillow full of dust mites or if you have a carpet full of cat allergen." (Talk to your physician for advice before buying an air filter.)
Be careful out there. It's important to avoid allergens all day long, not just in the bedroom, says Dr. Spector. "One of the main reasons people have nocturnal symptoms is because of allergic exposure early in the day. Let's say you have contact with a cat. You might have an immediate reaction, but hours later you may get a second reaction, known as a late-phase reaction." Talk with your doctor about triggers that may be causing a delayed response--whether it's fur, smoke or perfume--and ways to avoid them.
Measure your breath. A physician can show you how to use a peak flow meter, a simple, inexpensive device that measures the maximum amount of air a person can blow out. Dr. Martin instructs patients to use it when they go to sleep, first thing in the morning and if they wake up in the middle of the night, "even if they don't feel tight." These objective measurements can help your physician make an accurate diagnosis and develop a treatment program that's right for you.
Reschedule medications. In the old days, says Dr. Martin, asthma medication was taken at regular intervals. Now, specialists use an approach called chronopharmacology: targeting medication so it reaches peak effectiveness when asthma is at its worst, at night.
Based on Dr. Martin's pioneering research with asthmatics in his sleep laboratory, he makes several suggestions about the timing of leading asthma medications. (Of course, don't make any changes in your medication without consulting your physician. These include:
* Sustained-release theophylline A methylxanthine that opens the bronchial passages, this medication is best administered around dinnertime; that's 6 p.m., if the theophylline is a once-daily preparation. "Blood levels of this type of theophylline preparation usually peak around 10 hours after it's taken," explains Dr. Martin.
* Corticosteroids "Classically, oral steroids have been used in the morning," says Dr. Martin. "But we're finding now that if you use these potent anti-inflammatories at 3 p.m., you get a much better improvement in asthma at night." Dr. Martin's laboratory hasn't completed studies yet on timing of inhaled steroids, "but right now it appears to be a similar story; that they're most effective taken at 3 p.m."
* Long-acting beta-agonists, such as salmeterol (Serevent) These drugs open the airways and have been found to be very helpful for people with nocturnal asthma. Since the effects last about 12 hours, says Dr. Martin, when you take them isn't so critical. One important note: Salmeterol is not an emergency rescue drug. If you're having difficulty breathing, "Use your short-acting beta-agonist inhaler [Proventil, Ventolin, Maxair, for example] instead," says Dr. Martin. He emphasizes the point: "Some people who've tried to use salmeterol for breathing emergencies have died; it just doesn't act that quickly."
Treat sinusitis. An estimated 70 percent of asthmatics suffer from chronic sinusitis and postnasal drip. If cleared, both day and night asthma symptoms often improve, sometimes dramatically. Sinusitis symptoms include headaches above or below the eyes, often related to changes in the weather; stuffy nose; excess mucus, often yellowish; some blood in the mucus. Sometimes sinusitis has no symptoms; a physician must detect it.
The key to treating sinusitis is to decrease congestion so nasal passages can drain. Your doctor may recommend an over-the-counter or prescription decongestant. Regular irrigation of the sinuses with a saline solution, one to five times a day, also helps. A minority of people develop sinus infections, and antibiotics may be needed. Surgery is a last resort for chronic sinusitis.
Treat sleep apnea. In sleep apnea, breathing stops briefly but many times during sleep. Treating it can improve some people's asthma. An apnea diagnosis must be made by a physician and may require an overnight stay in a sleep laboratory. Treatment includes weight loss; avoiding alcohol; not sleeping on your back; medication; and in severe cases, a mask that you wear at night called a nasal CPAP (continuous positive airway pressure) to keep your airways free and clear from obstruction.
Stop the acid. It's possible that for some asthmatics, that bitter taste of acid reflux in the mouth means wheezing in the lungs. In gastroesophageal reflux, acid from the stomach backs up into the esophagus or mouth. It's worst at night because of the horizontal position. In rare cases, says Dr. Platts-Mills, people may actually breathe that acid into their lungs, contributing to inflammation.
Dr. Platts-Mills treats asthmatics with antacids, and suggests some self-help measures to reduce reflux. These include elevating the head end of the bed about four inches using books or bricks; sleeping on a high pillow; avoiding irritating foods; avoiding alcohol; avoiding late-night eating; and losing excess weight that puts too much pressure on the stomach.
If you're wheezing at night, take the time to talk to your doctor about designing a program to help you. Remember, nocturnal asthma is treatable. The benefits of top-notch asthma control and a good night's sleep will last you all day long.