We have just finished our 23rd annual Advances in Diagnosis and Treatment of Sleep Apnea and Snoring course in Orlando, Florida. This is one of my favorite events of the year because it includes a combination of surgical and nonsurgical topics and incorporates the true advances in sleep apnea and snoring. My talks focused on sleep apnea and snoring surgery, but I really enjoy the opportunity to learn from some of the world’s experts in sleep medicine when they discuss nonsurgical evaluation and treatment. This year was no different, and here are some highlights of the course, primarily the nonsurgical presentations.
As in most fields of medicine, there is substantial use of complementary and alternative medicine, particularly in the treatment of insomnia. Nalaka Gooneratne of the University of Pennsylvania spoke again on this topic. Some of the most common treatments in this category are chamomile, melatonin, . Melatonin is interesting because it is available over-the-counter in the United States, although there is wide variation in the availability of melatonin in these various supplements; he recommended melatonin from Life Extension Foundation as being of higher quality (note: I have no financial connection to this company). Studies show that the benefit of melatonin may be greater in patients over of the age of 60 and should be taken 2 hours before bedtime. Nalaka typically starts with 10 mg doses for 1 month, stopping if there is no benefit. If there is a benefit with that approach, he will try to decrease the dosage to the minimum that is effective, often decreasing to 1 mg or even 0.1 mg. Although there are fewer studies on other therapies, there may be some benefits to exercise (including tai chi and yoga), acupuncture, massage, and mind-body therapy like mindfulness training and meditation.
Allan Pack from the University of Pennsylvania spoke about major publications from the past year. The SAVE Trial received substantial attention as a randomized trial of CPAP vs. usual care with cardiovascular or cerebrovascular disease (including previous heart attack or stroke) and an apnea-hypopnea index of at least 12 events/hour. The group treated with CPAP had greater improvements in sleepiness, depressive symptoms, and quality of life. However, there was no effect on future cardiovascular events. The limitations of the study included the fact that CPAP use was relatively poor (3.3 hours per night), that almost two-thirds of the patients were Chinese, and that most Chinese centers had no previous experience in sleep medicine.
Precision Medicine in OSA: the PALM Scale, MRI, and DISE
Allan and Atul Malhotra from the University of California, San Diego spoke about different factors that contribute to sleep apnea, based on work from Atul and colleagues that is defining physiologic phenotypes and the PALM Scale. These factors include:
- anatomy and airway collapsibility (Pcrit), treated with surgery or oral appliances
- tendency to awaken easily (low arousal threshold) that may respond to sedative-hypnotic or sedative medications
- control of breathing (loop gain) that may respond to certain medications like acetazolamide or oxygen
- dilator muscle responsiveness to airway collapse (attempts to treat with carbon dioxide or medications have not been successful)
Atul and his colleagues at UCSD and Brigham and Women’s Hospital are working on simplified ways to determine the relative importance of these various components in individual patients. These individual treatments have not proven uniformly helpful, and it may simply be, as with surgery, that we need to define groups of patients who might benefit specifically.
Richard Schwab from the University of Pennsylvania spoke about his work with magnetic resonance imaging (MRI) that I have discussed on this blog previously. His team has evaluated fat deposition within the tongue in many patients with sleep apnea and has shown that there is variation in how much fat people will deposit with weight gain.
Paradigm Shifts in the Evaluation and Management of OSA
Sam Kuna from the University of Pennsylvania spoke about some dramatic changes that have been occurring in sleep medicine over the past several years. Two of these are the move to home (instead of in-laboratory) sleep studies and the use of automatically-adjusting positive airway pressure therapy instead of fixed continuous positive airway pressure therapy. He cited an interesting study that has just been published showing that outcomes using data from Level 3 home sleep studies (typical home studies) was the same as for Level 1 (in-laboratory polysomnogram) and better than Level 4 (oximetry) studies. The bottom line is that, for straightforward patients, the results are almost identical when using home sleep studies and automatically-adjusting positive airway pressure therapy. He later spoke about the use of telemedicine in the management of sleep medicine patients. In short, the results have been good but limited by some logistical hurdles and the desire of patients to check in on a daily basis with a website that can monitor their condition.
Andrew Goldberg from the University of California, San Francisco discussed the limitations of the over-reliance on the apnea-hypopnea index to define obstructive sleep apnea. There is a real need to incorporate other measures in how we define this disorder, as the apnea-hypopnea index is too simplistic when we are looking at how and whether we treat patients.
Nalaka discussed phone apps for the diagnosis of obstructive sleep apnea and snoring. He discussed some of the advantages and disadvantages of these. The good news is that smartphones are so common that they can provide access to care across the entire spectrum of society. On the other hand, many physicians are reluctant to incorporate this into their practice. In addition to the obvious hurdle of payment for such services (although there is a 99490 CPT code to bill insurance if one spends at least 20 minutes a month on this chronic care management), the issue is primarily that these technologies have not been studied extensively. The FDA does not regulate these aggressively because most are not used for true medical use like diagnosis or treatment. Some of the devices like Fitbit or the Jawbone UP3 rely on electrocardiogram data to determine the quality of sleep, with some good data supporting its role. Use of apps that are based on sound recording from a smartphone may be good for measurement of snoring but do not appear ready for use in sleep apnea.
Special Populations: Older Adults, Pregnancy, and Postmenopausal Women
Nalaka spoke about sleep apnea in older adults. He has led important research showing that, in older adults, there is an increased risk of mortality associated with moderate to severe sleep apnea only in those who also have excessive daytime sleepiness. Kristine Yaffe at the University of California, San Francisco had showed that untreated obstructive sleep apnea was associated with development of Alzheimer’s Dementia. Dr. Gooneratne discussed the interesting work showing that CPAP can delay the progression of cognitive impairment in individuals with mild but not advanced cognitive impairment. This finding is common in sleep apnea treatment, for example with hypertension, where CPAP prevents worsening but is not as effective in lowering blood pressure.
Grace Pien from Johns Hopkins University gave a lecture about sleep apnea during pregancy and in women after menopause. There is an increased risk of sleep apnea in both of these groups of women. The changes in menopause are not just related to age differences, as women of similar age have a greater likelihood of having sleep apnea if they have gone through menopause already. Interestingly, the risk of sleep apnea does not decrease with hormone replacement therapy. Women tend to have less of what are considered typical sleep apnea signs (taken from description of symptoms in men), such as disruptive snoring or obvious blocking in breathing. They can have more symptoms of sleepiness, insomnia, or other less “classic” sleep apnea signs.
Consequences of Sleep Apnea
Lee Goldberg from the University of Pennsylvania discussed the cardiovascular consequences of both central and obstructive sleep apnea. In summary, there is a clear association between sleep apnea and cardiovascular disease, such as high blood pressure (hypertension), irregular heart rhythms (arrhythmias), heart disease (coronary artery disease), stroke, and heart failure. It is not clear how much of an impact treatment of sleep apnea has, but it appears that there is a decrease in blood pressure, particularly with treatment of obstructive sleep apnea in drug-resistant hypertension.
Allan spoke about the growing evidence on the potential link between sleep apnea and cancer that is summarized in a recent review article. There appears to be an increased likelihood of cancer (and death due to cancer) with sleep apnea, especially those with significant decreases in oxygen levels during sleep and in those over 65 years of age. Animal studies have suggested that sleep disruption (fragmentation) and intermittent decreases in oxygen levels may play key roles in this process. While these topics could benefit from additional research, Allan highlighted the real need for evaluation of whether there are reductions in cancer or cancer outcomes from treatment of sleep apnea.
Obesity and Weight Loss
Gary Foster of Weight Watchers discussed the obesity epidemic and treatment with lifestyle and dietary modification, medications, and surgery. Here are some of his conclusions. Obesity is present in a high proportion (over 80%) of obese adults with type 2 diabetes. Weight loss benefits sleep apnea, with greater degrees of weight loss associated with greater improvements in sleep apnea (and in hemoglobin A1c in patients with diabetes). Lifestyle and dietary modifications have a roughly 5% weight loss. The exciting news is that the last 5 years have seen approvals of a number of new medications to combat obesity, with an approximately 10-15% reduction in body weight. Weight loss surgery (sleeve gastrectomy appears to be the most common procedure in the United States at this time) achieves about a 35% weight loss (albeit in patients with more weight to lose). One other new device is called AspireAssist, with a study showing that it does work but some concerns about whether this approach that may or may not be as acceptable to patients.
Andy Goldberg then spoke about the gut microbiome. Bacteria (and other organisms like fungi) are everywhere outside and inside our bodies, and the constellation of organisms is called the microbiome. It turns out that there are differences in our microbiome (the ratio between the Bacteroides and Firmicutes taxa being the most examined in the intestinal tract) that are associated with (not necessarily causing) conditions like obesity, asthma, and chronic rhinosinusitis. This is a fascinating area of research, and my hope is that more work will spell out the extent to which we might be able to treat obesity with restoring or creating a healthier microbiome.
Advances in Sleep Apnea and Snoring Surgery and the ISSS Meeting
I have focused in this post on the nonsurgical presentations. We had a number of excellent talks on snoring and sleep apnea surgery from a number of excellent speakers: Boyd Gillespie from the University of Tennessee, Ron Mitchell from the University of Texas Southwestern, Erica Thaler from the University of Pennsylvania, Ed Weaver from the University of Washington..and me. With that in mind, I wanted to acknowledge that the upcoming meeting of the International Surgical Sleep Society on May 5-6, 2017, should be the best sleep surgery educational program of the year. The final program has just been released, and I recommend it to all surgeons (and dentists) interested in sleep apnea and snoring. People should feel free to contact me to learn more about this organization and our scientific meetings.