Have you ever woken up in the morning feeling just as tired as you were when you went to sleep? Or perhaps you have experienced being woken up by your partner’s loud snoring? If so, then you or your loved one might be suffering from what is known as Obstructive Sleep Apnea.
Obstructive Sleep Apnea (OSA) is characterized by repeated cessation of breathing due to obstruction of the upper airway when one is asleep. This results in a decrease in oxygenation in the body. Symptoms of OSA include loud, disruptive snoring, witnessed apneas during sleep, and daytime fatigue.
According to a study, OSA is associated with various negative consequences, such as impaired quality of life, depression, metabolic diseases, cognitive decline, drowsy driving and an increased risk of motor vehicle accidents.
We sit down with ENT specialist Dr. Soon Sue Rene and cardiologist Dr. William Kristanto to hear more from them on the ins and outs of obstructive sleep apnea, its relationship with cardiovascular diseases, and how it can be treated.
According to Dr. Soon,OSA is a common problem in Singapore, with approximately 30% of Singaporeans suffering from moderate-to-severe OSA.
“It's generally characterized as a complete or incomplete upper airway collapse, and that results in a decrease in oxygen delivery to your body,” Dr. Soon adds. This can create an effect similar to a feeling of being choked repeatedly throughout the night. If left untreated, OSA may gradually predispose one to many health conditions.
Dr. Kristanto recalls a patient who was diagnosed with severe OSA (Apnea-Hypopnea Index of 100 events/hr on sleep study) and had a BMI of 40, coupled with nasal polyps that had obstructed his nasal passage. His condition was made worse as the patient drank excessively.
As Dr. Kristanto puts it, “This patient is roughly being strangled more than 100 times in an hour.” In addition to this, this patient also does not get enough sleep. “This means that not only is his quantity of sleep low, but his quality of sleep is also poor. You can imagine the amount of stress his body undergoes,” Dr. Kristanto adds.
“So, when he's sleeping, the brain tries to wake the person up by secreting stress hormones, and that is what causes hypertension”
According to Dr. Soon, obesity is a known risk factor for OSA. “When one is overweight or obese, there is associated increased fat deposition in the tissues of the upper airway. This results in a narrower pathway, which in turn predisposes you to OSA.”
Other risk factors for OSA include upper airway structural issues (e.g. small or receded chin, enlarged tonsils), family history of sleep apnea, and gender (males tend to be more susceptible to OSA, although females have a higher risk of developing OSA post-menopause), she adds.
OSA has a close relationship with heart diseases and is increasingly recognized as a major contributor to cardiovascular morbidities including systemic and pulmonary arterial hypertension, heart failure, acute coronary syndromes, atrial fibrillation, and other arrhythmias.
As Dr. Kristanto shares, this is due to the fact that when you experience an upper airway obstruction in your sleep, the level of oxygen in your blood decreases. This will cause your body to try to wake you up or change your sleeping posture by secreting certain chemicals and hormones, such as adrenaline.
When someone with OSA experiences apnea and hypopnea during sleep, their blood pressure will increase.
“An increase in blood pressure is never good,” Dr. Kristanto says. “It can cause heart attacks, and over time, there will be structural changes to your heart. This can cause atrial fibrillation that, over time, would predispose you to the risk of having strokes.”
He adds, “So most times, when I review my patients and I notice they have a history of hypertension, I dwell deeper into their sleeping habits and ask their sleeping partner whether they noticed that their partner sounds like they are being choked. Normally, they would complain, ‘Yeah, my husband makes a lot of noise, snoring very loudly and occasionally stop breathing.’”
This response, according to Dr. Kristanto, would raise his alarm bells and might be indicative of OSA.
A study found that OSA increases your risk of heart failure by 140%, the risk of stroke by 60%, and the risk of coronary heart disease by 30%. The link between OSA and cardiovascular disease is further corroborated by evidence that treatment of sleep apnea with Continuous Positive Airway Pressure (CPAP) reduces patients' blood pressure and improves the functions of their heart muscles. CPAP, a medical device used in the treatment of OSA, is often considered the gold standard for OSA treatment.
“It functions as a mechanical splint that patients put over their noses or over their faces to deliver an airway column to keep the upper airway stented and open, so that the upper airway doesn't collapse when they're breathing,” Dr. Soon explains. “This helps stabilize their oxygenation overnight when they sleep, decreases oxidative stress and prevents all the other cardiovascular complications that Doctor William has spoken about.”
Unfortunately, not every patient will be able to accept CPAP as a form of treatment for their OSA.
It has been observed that compliance with CPAP therapy ranges from 30% to 60%, with adherence to CPAP in those with mild OSA being even lower. This could be due to a number of reasons, such as physical discomfort while wearing the apparatus, psychological stress, or financial burden.
The effectiveness of CPAP is also dependent on using the device correctly and consistently. There are patients who experience issues with the mask when using CPAP, reporting mask discomfort, skin irritation or feelings of claustrophobia. While others have reported complaints of pressure intolerance, or experiencing trouble exhaling against the CPAP pressure.
“I have patients who look at a machine and reject it right away,” Dr. Soon says. “They can't believe that they have to be hooked on this machine forever, every night. They'll ask me, ‘Is it temporary?' or ‘Is it permanent?’ And you can imagine if you have a young family or have yet to get married, or if you are a frequent traveller, lugging this machine around can be a hassle or a social hindrance.”
For the group of patients who do not want to undergo CPAP therapy, surgery can be an alternative option for selected patients.
“Naso-endsocopy can be performed comfortably in the ENT clinic to evaluate the upper airway. This simple procedure can give us valuable information if one is a suitable surgical candidate for upper airway soft tissue surgery for obstructive sleep apnea.” Dr. Soon explains.
She elaborates that surgery as a treatment option is better suited to healthy young adults, with BMI in a normal range, with obvious sites of airway obstructions such as swollen turbinates, adenoids or tonsils. Some of her patients have been cured of OSA through surgery, with evidence of normalised sleep study test results repeated post-operatively.
“However, once you hit the middle age groups, there are other factors such as tissue laxity, obesity, other medical conditions which contributes to the severity of OSA which affects surgical results,” she adds.
Dr. Kristano elaborates further, “Weight loss is one of the key factors in the management of OSA, with a lot of OSA patients not being active enough. They have sedentary lifestyles, high BMI, which leads to high blood pressure, poorly controlled diabetes, and high cholesterol.”
He advises his patients that every small thing adds up, and they should try their best to curb whatever they can. In conclusion, sleep is important to good health. Hence, If you feel that you have sleep apnea or symptoms suggestive of sleep apnea, don't neglect the signs and go consult a sleep specialist to get it checked out.
