Senior medical director, Sleep Centers of Middle Tennessee and OSAinHome; chairperson, MTSU Sleep Research Consortium
If hypertension is the silent killer, then snoring—and its accompanied condition, obstructive sleep apnea—is the loud killer. Raising awareness of OSA on World Sleep Day is of utmost importance.
This year, the third week of March is Sleep Awareness Week, which this year culminates today, March 19, 2021, with World Sleep Day. The purpose is to promote better sleep and increase awareness of the 90 different sleep disorders. The most dangerous sleep disorder, though, is obstructive sleep apnea (OSA), which untreated has up to a 40% mortality within 12 to 15 years.1,2
Based on hazard ratios, OSA may present an even greater cardiovascular mortality than hypertension (HTN).1,3 HTN is known as the “silent killer” because it often goes unnoticed until it has wreaked havoc on the cardiovascular system. If HTN is the “silent killer,” then OSA is the “loud killer.” Loud because most patients with OSA snore—and up to 87% of those who do snore have OSA.4
Snoring is no longer a laughing matter. It is the sound of a partially obstructed airway and the sound of someone struggling to breathe in their sleep. It is the sound of someone likely to be sleepy or fatigued the next day. It is the sound of someone more prone to depression, anxiety, and cognitive issues. It is the sound of future HTN, type 2 diabetes (T2DM), and cardiovascular disease (CVD).
OSA is majorly associated with hypertension. In response to the partially obstructed airway, the body triggers the “fight or flight” reaction (sympathetic activation) with norepinephrine release, which momentarily relieves the obstruction (snoring). We created the acronym “S-Nore-R” for sleep-norepinephrine-release to connect the norepinephrine release to snoring. With OSA, S-Nore-R can occur hundreds of times each night and since norepinephrine raises blood pressure, it becomes obvious why continuous positive airway pressure (CPAP) improves HTN.5 Between 60% and 83% of patients with HTN have OSA.6,7 As far back as 2003, the Joint National Committee on HTN recommended that all patients with HBP who snore be tested for OSA.8
The “loud killer” is also likely a significant cause of T2DM. Up to 86% of patients with T2DM have OSA.9 S-Nore-R raises blood sugar, and thus insulin levels, which likely participates in the development of insulin resistance and T2DM. Just 2 weeks of CPAP can improve insulin resistance and CPAP lowers hemoglobin A1c.5,10 Patients with T2DM need to be tested for OSA regardless of whether or not they snore. These patients should not miss the potential benefits of improving their blood sugar control without adding further medication. The International Diabetes Federation Task Force began recommending the screening of patients with T2DM for OSA in 2008,11 but despite the recommendations, only 5% of T2DM are on treatment for OSA.12
OSA is additionally strongly associated with increased morbidity and mortality from cardiovascular disease (CVD).13-15 The frequent S-Nore-Rs, the decreases in blood oxygen levels, and the more negative thoracic pressures caused by airflow obstruction can lead to multiple types of CVD including atrial fibrillation, stroke, transient ischemic attack, heart failure (HF), coronary heart disease, myocardial ischemia, myocardial infarction, and sudden death.16-18 The mechanisms have been extensively reviewed.15 Between 60% and 82% of patients with heart disease have OSA.19-22 We recently published a short review summarizing the evidence that “wearing” CPAP to treat OSA reduces cardiovascular events.23 Patients with heart disease, especially any that snore, should be tested for OSA so they do not miss the potential benefits of CPAP. Yet, in one study, <5% of patients with heart disease underwent evaluations for OSA.24
While screening for HBP, cholesterol, and T2DM are standard in medical practice, testing for OSA is uncommon and as many as 90% of cases are undiagnosed.25 The main reason for underdiagnosis is the lack of OSA awareness among many healthcare providers. Treatment of HTN and elevated cholesterol have been around for more than 60 years. Until recently, there was little to no sleep curriculum in medical training programs. There are also no pharmaceutical companies behind the scenes pushing OSA awareness in medical practices.
OSA shares a single week of awareness in March, while HTN, T2DM, cholesterol, and heart disease each have their own month. That may change in a few years when the first medications to treat OSA are released. Pharmaceutical companies will then try to put OSA in the forefront. Unfortunately, the tablets in current trials are just for milder cases and specific subtypes of OSA. Plus, CPAP has over 30 years of outcome data, and even if found to be safe, it will take years to complete similar studies with a medication. CPAP will remain the safest, most effective, least expensive, and most supported treatment in the literature.
Additionally, the name “OSA” may be keeping many patients from treatment. The name is misleading, particularly the word “apnea.” An apnea is a complete obstruction to airflow, but most obstructions that cause S-Nore-R are partial obstructions to airflow which usually make the snoring noise. Many patients with OSA do not have apnea. The name “OSA” causes many providers to think their patients have to “stop breathing” or “hold their breath” in their sleep to undergo testing. They do not realize that snoring alone is enough reason to refer for sleep testing.
The name “OSA” was coined by Christian Guilleminault in 1976 when early sleep studies only measured apneas. In 1988, Gould et al first showed that partial obstructions (which are far more common) had the same sequela as apneas.26 However, the name was never changed. Our group has begun experimenting with a modernized name and understanding for OSA (including S-Nore-R) that, so far, is helping more patients understand and adhere to treatment.
For many patients, there are still obstacles. In some instances, OSA testing can be inconvenient and expensive, and it can take weeks to months to begin treatment. CPAP is still wrongly perceived by many as a gas mask-like device leftover from World War I. Most importantly, the great value that CPAP can add to one’s life is not well understood. However, we have found that with effort these obstacles can be overcome.
In January 2020, before the COVID-19 pandemic came to the US, Sleep Centers of Middle Tennessee (SCMT) introduced a program to diagnose and treat OSA inexpensively, quickly (within days), and without the patient even having to leave their home. The program is called OSAinHome and is already accepting patients from 7 states in the southeast. After a phone interview at no charge, appropriate patients are shipped a high-tech but simple-to-use sleep testing device to wear in their homes. The device uploads to the cloud in the morning and a telemedicine visit with a sleep medicine provider follows. For those who need CPAP, it is then shipped to their homes with a cellular modem inside their device so that we can care for them remotely. Instructions and education can all be done virtually.
For most patients, we have made diagnosing and treating OSA as fast as ordering a lipid profile and starting a statin. Over 5 years, based on the prices from the popular CPAP.com and GoodRx websites, the cost of testing and treating OSA is similar or even less than testing for and treating elevated cholesterol with statins.27-29 The exception would be if you had your sleep test in a hospital-owned sleep facility.
Historically, CPAP usage has been poor,30-32 with as little as 25% to 35% of patients using at 1 year. In January 2021, our group published results from 4100 patients showing patients provided CPAP by SCMT (an Integrated Sleep Practice) were 50% more likely to wear their CPAP long term than if CPAP was provided by a medical equipment company.33 The study, a joint effort by Middle Tennessee State University (MTSU), Vanderbilt University, and SCMT, showed 89% of patients still using CPAP at 3 months, but only 66% at 1 year. The study was done with only 3 months of remote patient monitoring. Today, SCMT monitors CPAP patients for 7 months and >85% are still using at 1 year. These results require a large amount of integrated effort and focus by the whole staff. Today, SCMT patients are more likely to use CPAP than take their cholesterol medication,34 mainly because cholesterol medications do not make you feel great in the morning like CPAP.
This week, begin to remove the “loud killer” from your practice. Just as you check every patient’s blood pressure, ask every patient if they snore—and remember, half of snorers deny it, so ask them if their bedpartner says they snore. Additionally, ask them what it would be worth to feel 50% to 100% better every day and to have more days to live. As of 2019, 37% of adults in the United States have OSA,35 and the prevalence is likely higher in your waiting room. The “loud killer” must be stopped.
William H. Noah, MD, has been practicing sleep medicine for more than 25 years. He is the senior medical director for Sleep Centers of Middle Tennessee and OSAinHome. He is also Chairperson of the MTSU Sleep Research Consortium.