Vol. 49 Sleep apnea is not just a 'disease of the overweight.' It can affect you even if you are thin.

When people hear the term Sleep Apnea Syndrome (SAS), many have a specific image in mind: a stout, middle-aged man sleeping while snoring loudly.

This image is half correct, and the other half is a very dangerous misconception.

It is true that obesity is a major risk factor for SAS. If fat accumulates around the neck, the airway is more likely to narrow, and gaining weight does indeed worsen SAS.

However, the conclusion that 'therefore, if you are thin, you are fine' is completely invalid. If you misunderstand this, you end up arbitrarily ruling out a life-threatening disease from your own health concerns.

I myself am living proof to the contrary.

When I was diagnosed with severe SAS, I was in my 20s and actually on the thin side (I wrote about the detailed circumstances at that time in [Special Issue] The Wish of a Sleep Specialist Diagnosed with Ultra-Severe Apnea | Dr. O). Why would a thin young person become so severely ill? The key lies not in fat, but in skeletal structure.

East Asians, including Japanese people, tend to have smaller, more recessed jaws compared to Westerners. Having a small jaw means that the space in the throat airway behind it is inherently narrow.

When factors such as age-related weakening of throat muscles, slight weight gain, or drinking alcohol before bed are added to an already narrow foundation, the airway can easily become blocked, even in thin people.

While SAS in the West is 'obesity-driven,' a significant number of Japanese SAS cases are 'skeletal-driven.' This is something I strongly feel in clinical practice. It is by no means rare for a slim person to be diagnosed with a severe case after undergoing testing.

There is another deeply rooted misconception, alongside the obesity myth: the idea that it is 'a disease that makes you unbearably sleepy during the day.'

Certainly, intense daytime sleepiness is a representative symptom of SAS. However, there are countless SAS patients who are barely aware of any sleepiness at all, even if they have a severe case.

I myself experienced sleepiness, but at the time, I dismissed it as 'because I'm busy with work.' The individual concludes, 'I'm not sleepy, so I don't have SAS.' However, throughout the night, their brain and heart are definitely under constant strain. The presence or absence of sleepiness is absolutely not a basis for ruling out SAS.

So, what clues should we look for?

Ironically, the most reliable signs are things you cannot notice yourself. Loud snoring pointed out by family or partners. And more importantly, the cessation of breathing—'the snoring stops suddenly, and after a moment of silence, there is a loud, gasping breath.'

That is the moment that makes the person sleeping next to you freeze. If you have ever been told this, it is well worth having a proper examination, regardless of your body type or whether you feel sleepy.

To add one more thing, health checkup results can also be a clue. If you are young but have high blood pressure, or have been pointed out to have unexplained polycythemia (high red blood cell count)—these findings can sometimes reflect nighttime hypoxia.

Simply having the perspective to consider whether there is an underlying sleep issue, rather than just brushing off checkup results as 'no abnormalities/observation required,' increases the probability of detection.

There are other indirect signs as well. High blood pressure that doesn't go down even with medication. Nocturia, where you wake up to go to the bathroom multiple times during the night. Headaches upon waking that don't feel refreshing. If these are all present, I want you to keep in the back of your mind the possibility that SAS may be lurking in the background.

The examination itself is not as daunting as you might think. In many cases, it starts with a simple test you can do at home. You just sleep for one night with sensors on your finger and nose. If it is strongly suspected there, you proceed to more detailed testing.

Many people put it off because they brace themselves, thinking, 'I have to be hospitalized and undergo a formidable examination,' but the entry point is much easier. If you have any concerning signs, please first consult your family doctor or a medical institution that handles sleep disorders.

'I'm thin, so I'm fine' or 'I'm not sleepy, so it's not me.' How many people have had their diagnosis delayed by these two misconceptions, accumulating risks of hypertension and heart disease in the meantime?

As a specialist, and as someone who was once a thin patient with severe sleep apnea myself, I want to state this clearly: SAS is not a disease you can rule out based on appearance.

Source:

Gottlieb DJ, Punjabi NM. Diagnosis and Management of Obstructive Sleep Apnea: A Review. JAMA. 2020;323(14):1389-1400.

*The content of this note represents the author's personal views and is in no way related to the views of the medical institution the author is affiliated with. While every effort has been made to ensure the accuracy of the content, please let me know if you find any inappropriate information.