When 33-year-old Shekar’s wife Anjana (names changed) first began to complain about his snoring, he brushed her concerns aside. “Just roll me over to the side, and go back to sleep,” he told her with a laugh. But as the months passed, Anjana began to notice more disturbing patterns in Shekar’s sleep. Now, he was not only snoring, but frequently waking up for a few seconds with a gasp, as if he couldn’t breathe. Finally, to settle her worrying, Shekar went to an ENT specialist, who recommended a sleep study. The results came as a revelation to Shekar: his sleep was broken at least 30-40 times an hour, as his oxygen-deprived body struggled to get more air into his lungs.
For most of us, snoring is just a minor irritation, more a laughing matter than a genuine concern. After all, we think, it’s just a sign of very deep sleep. But, as Shekar found out, snoring could be an indicator of a much deeper health problem called obstructive sleep apnoea (OSA). If not treated, his doctor explained to him, his OSA could lead to hypertension or high blood pressure, heart problems, diabetes, or even a stroke or a myocardial infarction (commonly called a heart attack).
What is obstructive sleep apnoea?
Obstructive sleep apnoea occurs when the windpipe gets blocked by the tonsils, tongue and so on. Most commonly, the flexible soft palate and the tongue collapse, blocking the passage through which air passes from the nose and mouth to the lungs. As a result, the lungs do not receive enough air, and the whole body is deprived of the oxygen required.
“Our normal oxygen saturation level is at least 95-96%. But we see cases where people’s oxygen levels drop to even 60% when they are sleeping. That means their heart and brain is getting very less oxygen. This is not a trivial issue at all,” says Dr Krishna Kumar, Senior ENT Specialist, Apollo Hospital.
While there is insufficient research focused on OSA, available statistics indicate that roughly 2-5% of Indian men and 1-2% of Indian women suffer from this condition. This implies that about 34 million people suffer from sleep apnoea. Importantly, over 80% of these cases go undiagnosed.
Signs, symptoms and risk factors
There are several signs and symptoms that you should look for to know if you might have sleep apnoea. While snoring is one of the prominent indicators, there could be people who have OSA without snoring as well. The other common signs and symptoms include episodes of not breathing during sleep, gasping for air during sleep, waking up with a dry mouth, morning headaches, difficulty staying asleep, daytime sleepiness, difficulty paying attention during waking hours and irritability.
There are several factors that could make you more prone to developing OSA. These include excess weight or obesity, thicker neck circumference, narrowed airway, being male, older age, family history of snoring, use of alcohol or sedatives and smoking.
Lack of awareness
Dr Krishna Kumar says that one of the biggest difficulties faced in relation to sleep apnoea is the lack of sufficient awareness of this problem. “In Western countries, you can even be denied a driver’s license if you have OSA, because you might doze off at the wheel. But here we are not that strict. So many people come to us complaining about daytime sleepiness. Some say they regularly doze off during the day. But they don’t realise it’s a symptom of OSA.”
Even among the medical fraternity, he adds, there is not enough attention given to sleep apnoea and the harmful consequences that can result.
How OSA is diagnosed
Dr Krishna Kumar says that the techniques for diagnosing and treating sleep apnoea have significantly improved in the last few years. The most common diagnosis technique is a sleep study, where instruments monitor a person while they sleep, to check the Apnoea-Hypapnoea index, number of stops in breathing or incidents of shallow breathing in an hour. Besides this, doctors also look at the Respiratory Distress Index (changes in sleep due to effort to breathe) and snoring index.
One of the more recent innovations in the area of diagnosis, says Dr Krishna Kumar, is called DISE, drug-induced sleep endoscopy. In this technique, patients are placed in a drug-induced sleep, and an endoscopy is performed on them while they sleep to discover which parts of the respiratory passages are getting blocked and why. This technique, however, is still not prevalent enough, he adds.