—Nancy A. Collop, MD, is an Associate Professor of Medicine at Johns Hopkins University in Baltimore and the Medical Director of the Johns Hopkins Sleep Disorders Center. In addition to her responsibilities as the newest Editorial Board member of Pulmonary Reviews, Dr. Collop excels as a clinician and researcher, particularly in the relatively new discipline of sleep medicine. Here, she shares her expertise.

Pulmonary Reviews: What do you do as Associate Professor of Medicine and as the Medical Director of the Johns Hopkins Sleep Disorders Center?

Dr. Collop: Most importantly, I evaluate and treat a wide variety of patients with sleep disorders. In addition, since this is a training institution, we see and review cases that are presented by physicians in training. [I also] manage the sleep center, which is currently two beds but will be up to six beds by the end of this year. I order, review, and interpret overnight and daytime sleep studies. In addition, part of that is teaching sleep fellows about the techniques of polysomnography. I collaborate with research trials as well.

Pulmonary Reviews: What kind of evaluation do patients undergo at the Johns Hopkins Sleep Disorders Center? And what kinds of treatment do they receive?

Dr. Collop: We have a busy sleep clinic where patients are evaluated by residents, fellows, nurse practitioners, or the staff physician, [which includes] a history and physical. As far as diagnostic studies, we do overnight polysomnography, multiple sleep latency testing, maintenance of wakefulness testing, continuous positive airway pressure [CPAP], bilevel positive airway pressure, and oxygen titrations. We also have an insomnia program that can administer cognitive behavioral therapy.

Pulmonary Reviews: Sleep medicine is a relatively new field. How has it evolved over the years?

Dr. Collop: One of my hats is as President of the American Board of Sleep Medicine, and through that I’ve seen a lot of things change. [The organization] was incorporated in 1991, and over the years the number of MDs and PhDs who’ve taken their exam has steadily increased. Now, there are more than 3,000 sleep medicine specialists who have that certification. One thing that’s evolved is that next year, the American Board of Medical Specialties will offer a certification exam in sleep medicine.

On a parallel track, the AASM [American Academy of Sleep Medicine], since the late 1980s, has had mechanisms to accredit sleep fellowships. The agency that is the standard agency for creating fellowships—the American Council on Graduate Medical Education—is now accrediting sleep fellowships, starting last July. The AASM also does sleep center and sleep laboratory accreditation. There are now more than 900 centers that have been accredited. In addition, the NIH has its own research center for sleep disorders. There are plenty of sleep medicine–specific journals, and many of the major journals now have significant sleep-related content. There’s also a new subspecialty in behavioral sleep medicine for psychologists and an exam for these fellowships.

Pulmonary Reviews: What’s new in sleep medicine? What recent advances are being made in uncovering the etiology and treatment for sleep disorders?

Dr. Collop: One of the more significant discoveries in recent years was related to research [that] ultimately pertained to the mechanisms of narcolepsy. One group was working on a mouse model, looking at appetite suppression and enhancement, and another group was looking at narcolepsy in dogs. Both groups found the same novel neurotransmitter. One group called it orexin, and the other called it hypocretin. [Dysfunction of] that transmitter is probably [at the core of] narcolepsy. It was a novel finding of a neurotransmitter that we never knew about which has profound implications regarding sleep and wakefulness.

We now know a lot more about circadian rhythm disorders and have identified genes that regulate these rhythms. There’s been a lot of work surrounding the mechanisms and treatment of insomnia. Many people with chronic insomnia have a specific type of hyperarousal state. We’ve found a phenotype that fits insomnia. There have been many data targeting behavior therapy in tandem with pharmacologic therapy for insomnia. The other thing that’s gotten a lot of press has been the effects of sleep deprivation and [the impact of this problem] on the individual and society.

Pulmonary Reviews: How are sleep medicine and sleep disorders important in clinical medicine in general?

Dr. Collop: Every patient that comes to a doctor sleeps. We know that the quality and quantity of sleep affects health. There are many data about obesity and its relationship to sleep time—and how sleep or the lack thereof may predispose someone to obesity. The treatment of many diseases involves drugs that can affect sleep. This can affect the underlying disorder. Of course, the illness itself—like COPD, asthma, or heart failure—can affect sleep [and vice versa]. [In these diseases,] exacerbations occur at night. We’re trying to understand how sleep deprivation affects the underlying disease.

In sleep apnea, which is a lot of what I do, there is a ton of literature now about its association with hypertension, diabetes, stroke, and heart disease. Really, sleep medicine spans the spectrum of all medicine. You can look at any part of medicine and find that sleep has an effect.

Patients don’t often think that sleep is important, and doctors don’t ask about it. It’s an area that needs more investigation from any doctor. You spend a third of your life sleeping, and disruption or lack of sleep can have substantial adverse effects.

Pulmonary Reviews: Can you comment on the importance of sleep medicine and disorders in pulmonary medicine?

Dr. Collop: The obvious conditions that pulmonologists come across are hypoventilation syndrome, sleep-disordered breathing, and sleep apnea. [These disorders are not uncommon], particularly with the increase of obesity in our country. Additionally, both COPD itself and the drugs used to treat it can cause sleep-disordered breathing. COPD patients also have more dramatic drops in their oxygen levels when asleep versus when awake. As I’ve mentioned before, asthma often flares at night.

We know that pulmonary hypertension occurs in about 20% of sleep apnea patients, though it tends to be relatively mild. Some of our research looks at the effects of sleep-disordered breathing on patients who already have pulmonary hypertension. There is very little information about that. Other pulmonary disorders such as sarcoidosis and COPD have an increased prevalence of comorbid sleep apnea, which has an effect on the underlying disease.

Pulmonary Reviews: How has sleep medicine played a role in the training and certification for pulmonary medicine?

r. Collop: Currently, about 10% of the pulmonary certification board exam targets sleep medicine. So, sleep medicine is thought to be very important within pulmonary fellowship training. A lot of the pulmonary/critical care–trained physicians used to be able to practice sleep medicine. But that may be changing now that there’s an independent sleep medicine fellowship. For pulmonary/critical care–trained fellows to practice sleep medicine, they may have to get additional training.

Pulmonary Reviews: Sleep in the hospitalized and critically ill is often neglected in medicine. What research has been done in this area, and what can be done to help these patients sleep comfortably during their hospital stay?

Dr. Collop: That’s an area that I am very interested in. We know that sleep is disrupted in the ICU. Patients often get eight hours of sleep, but it’s spread out over 24 hours and is much more fragmented than sleep at home. That fragmentation probably relates to underlying illness, noise, the need to do procedures or measure vital signs, and the drugs that we use. The ICU has diverse patient populations, and the effects of sleep deprivation vary from one person to the next. In one ICU bed you may have a COPD patient, and in the next bed, a sepsis patient. They may react differently to sleep deprivation. There aren’t many data on whether improving the ICU environment by keeping noise levels down will improve sleep. We’d like to think that it does, but there are few outcome data suggesting that is the case.

[In hospitalized patients], you may not get the chance at any other time to identify them as having a sleep disorder. We don’t do much to screen people. At Johns Hopkins, we see people with poor access to care. When they’re hospitalized, it’s an opportunity to identify sleep disorders. But no one has looked at that in a systematic way. If patients do have a sleep disorder, how does that affect their hospitalization?

Pulmonary Reviews: Obesity is a well-known risk factor for sleep apnea, and losing weight could ease the symptoms, if not cure the condition. How do you counsel patients on weight loss and other modifiable risk factors?

Dr. Collop: When I am presented with a morbidly obese patient, the best option is often gastric bypass, which has very good efficacy to treat sleep apnea. Weight loss is something that we always recommend for the overweight or obese patient with sleep apnea. Unfortunately, we don’t have a great hospital-based program for weight loss, so it has to be self-motivated or [a program such as] Weight Watchers. However, most patients, even if they lose enough weight to treat their sleep apnea, need long-term follow-up in case weight gain recurs.

Pulmonary Reviews: Compliance rates for therapies like CPAP are notoriously low. How do you facilitate compliance with these therapies?

Dr. Collop: It’s interesting ... a recent talk I attended was on patient adherence to therapy [in general]. If you look at studies of patients with chronic medical illnesses, it’s consistent that adherence to therapy is about 50%. In CPAP studies, adherence is anywhere from 50% to 80%. When you say "notoriously low," it’s really no lower than anything else that we do in medicine with regard to therapy for chronic illness. There’s this perception that nobody wants to wear a CPAP machine, but [compliance] is probably no worse than [in] taking blood pressure medicine or using insulin. To improve adherence, early education is key. I educate patients from the moment I see them and suspect [a diagnosis of] sleep apnea. I talk about CPAP and how it works. Once they get CPAP, I follow them up in clinic after they’ve been on it for three or four weeks to troubleshoot any problems. I often use compliance information, obtained through the CPAP device. I believe it is very helpful feedback for the patients.

Pulmonary Reviews: What advances are being made in producing easier, more comfortable therapies?

Dr. Collop: The basic premise behind CPAP is that you must pressurize the airway. What’s improved is the way we can do that. There are a number of different masks and types of headgear for patients. The addition of humidifiers to CPAP has helped. A new modification in a particular machine makes the pressure easier to tolerate during exhalation. There are also dental appliances that give patients a reasonable alternative to CPAP. Areas of research might be in drugs that increase muscle tone in the airways or that facilitate weight loss.

Pulmonary Reviews: What role do surgical therapies, like removal of the tonsils and adenoids and uvuloplasty, play in the treatment of sleep apnea?

Dr. Collop: In children, the treatment is surgical. Tonsillectomy and adenoidectomy have about an 80% success rate in children. In adults, surgery has a small role. I always tell patients that it’s like flipping a coin: There’s a 50% chance that it will help. The other problem is that [the condition] often relapses over time. There are very few long-term data showing persistent improvement in [adults] who’ve had surgical therapy. I’m hesitant to recommend it for most adults.

Pulmonary Reviews: Are there evidence-based guidelines to follow for the treatment of sleep disorders, and are these guidelines being followed?

Dr. Collop: There are a lot of evidence-based guidelines. A lot of them come from the AASM. There are evidence-based guidelines on when to use polysomnography, actigraphy, multiple sleep latency testing, and portable monitoring, and for the treatment of insomnia. The American College of Chest Physicians has done a nice evidence-based guideline on use of noninvasive ventilation. It takes physicians a long time to hook onto them, though.

Pulmonary Reviews: Do you have anything that you’d like to add?

Dr. Collop: Sleep medicine is a unique and eclectic field that draws from a number of different disciplines. That’s what makes it interesting and challenging. Hopefully, hospitals and medical institutions will realize that the approach to sleep medicine needs to be multidisciplinary. Everyone can then benefit from the interactions among the different specialties that are involved.

—Tamara Gibb

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