As a pulmonologist and sleep medicine specialist, I see many patients who suspect they have sleep apnea. But many patients don’t know that they may also have a condition known as obesity hypoventilation syndrome (OHS). In fact, at least 1 in 12 people with sleep apnea also has OHS — and the condition can be life-threatening if not treated.
When I diagnose a patient with OHS, they may not know much about the condition. I take the time to sit down with each patient to address their questions and concerns. I make sure they understand what OHS is, how it affects their health, and how treatment can help. Here are some answers to common questions I hear from my patients.
What is obesity hypoventilation syndrome?
OHS, also called Pickwickian syndrome, is a disorder in which poor breathing lowers oxygen and raises carbon dioxide in the blood. Obesity hypoventilation syndrome (OHS) affects breathing and sleep, as well as lung and heart health.
We aren’t sure what causes OHS. It might stem from the brain’s ability to control breathing. Narcotic medications, a deformity or injury to the lungs, hormones or hypothyroidism can play roles as well. Extra weight pressing against the chest wall can also make it hard to take a deep breath.
OHS can affect a person’s quality of life, and it may lead to serious health problems. Some complications of the condition include:
- High blood pressure (hypertension)
- Right-sided heart failure
- High blood pressure in the lungs (pulmonary hypertension)
- Depression, anxiety and irritability
- Increased accident risk
- Problems with intimacy and sex
People experiencing OHS can present with a variety of symptoms. These include:
- Depression
- Headaches
- Poor sleep quality
- Shortness of breath
- Sleep apnea
- Sleepiness during the day
- Swollen legs or feet (edema)
Poor sleep quality is often the symptom that pushes people with OHS to see a doctor and seek out a sleep study to find out whether they have sleep apnea. This makes sense, as about 90% of people with OHS also have obstructive sleep apnea. In some cases, patients may be diagnosed with sleep apnea, but the fact that they also have OHS is not recognized.
Underdiagnosis is a real worry, especially since 30% of people with OHS are diagnosed after they’re admitted to the hospital. In those cases, what typically happens is that the patient can’t wake up or their family notices that they are confused. When they come to the emergency department, we find they have an incredibly high carbon dioxide level. These are life-threatening situations.
That’s why I tell patients who think they may have sleep apnea or another sleep disorder that it’s crucial to be evaluated at a sleep center with an experienced team of specialists like the Temple Sleep Disorders Center. At Temple, you’ll see well-trained and very engaged physicians who truly care about their patients and look at their whole health when considering the correct diagnosis and treatment plan. They are up-to-date on the newest treatments, and they know how important it is to continue to monitor a patient’s condition after they’re diagnosed.
How is obesity hypoventilation syndrome diagnosed?
When I see patients who may have OHS, I perform a physical exam and look closely at the patient’s lab data, including kidney function and electrolytes. I look at the carbon dioxide level as well — if it’s above 27, it’s an indicator of OHS. Another thing we look at is body mass index (BMI). A BMI of more than 40 is a risk factor for OHS. The condition is also more common in men over 40 and women who have been through menopause.
I also run other tests to get a full picture of the patient’s health and the possible causes of their symptoms. Those might include:
- Imaging studies
- Lung function tests
- Sleep studies
- Echocardiograms
What treatments are available for OHS?
Noninvasive mechanical ventilation is often the first step in treating OHS. These breathing aids include continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BiPAP) machines. These are used during sleep with a mask that fits over your nose or both your nose and mouth. Both CPAP and BiPAP machines help people to get more air while they sleep. The difference is that CPAP machines deliver air at a constant pressure while the person using one inhales and exhales. BiPAP machines deliver air at a higher pressure when the user is breathing in than when they are breathing out, thus improving ventilation. Other forms of non-invasive ventilation are available as well, and patients may find these more comfortable to use. Unfortunately, CPAP resolves hypoventilation in only a minority of patients, and most patients will require a titration study in the sleep laboratory to determine which machine provides the best treatment.
To make it easier to sleep with a BiPAP or CPAP machine, Temple Health offers mask-fitting clinics where patients can learn about their condition and how to wear the mask. We make sure they get the right mask and are comfortable using the machine. Having an expert there to coach you through it will increase your success when you get home.
Using the machine can be an adjustment, but I tell my patients that it makes a world of difference to their quality of life — and their life expectancy. Sticking with treatment is crucial: When OHS patients stop using their CPAP or BiPAP machines regularly, their mortality rises. More than 50% of patients with OHS die within two years of stopping use of the machine.
CPAP and BiPAP machines also provide an incredible amount of data to your care team. We can access information about how you use your device. This, in turn, can help us help you better use your CPAP or BiPAP. We can also get diagnostic info, like carbon dioxide levels and air pressure. This data helps us understand and address — and sometimes even anticipate — symptoms and issues. This information helps your care team truly partner with you.
Weight loss plays another key role in OHS treatment. For many patients, bariatric surgery may be a way to take control of their condition. We’ve found that people usually need to lose about 25% of their weight to resolve OHS — more than most people can achieve through diet and exercise. Surgery may help patients reach their weight-loss goals.
At Temple Health, our multidisciplinary approach means that experts from pulmonology, cardiology, endocrinology, bariatrics and more work together to find the best path forward for our OHS patients. We have up-to-date information on the latest treatments, and we understand that effective care requires follow-up and long-term relationships.
Breathe easier with expert, comprehensive care
If you think OHS may be affecting you or someone you love, schedule an appointment with a Temple Health pulmonologist today. Call 800-TEMPLE-MED (800-836-7536) or request an appointment online.
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