My doctor from the sleep lab called back this afternoon with a report of my sleep study done on November 17th, saying I have developed severe sleep apnea –– as predicted by my family doctor and Apple Watch.
According to Johns Hopkins Medicine:
Obstructive sleep apnea can range from mild to severe, based on a measurement system called the apnea-hypopnea index (AHI). The AHI measures the number of breathing pauses that you experience per hour that you sleep.
Obstructive sleep apnea is classified by severity:
- Severe obstructive sleep apnea means that your AHI is greater than 30 (more than 30 episodes per hour)
- Moderate obstructive sleep apnea means that your AHI is between 15 and 30
- Mild obstructive sleep apnea means that your AHI is between 5 and 15
The sleep study shows I had 83 episodes per hour.
According to Harvard Medical School:
At sea level, a normal blood oxygen level (saturation) is usually 96 – 97%. Although there are no generally accepted classifications for severity of oxygen desaturation, reductions to not less than 90% usually are considered mild. Dips into the 80 – 89% range can be considered moderate, and those below 80% are severe.
My oxygen level during sleep was only 73%.
Protracted sleep apnea results in low blood oxygen level and gives rise to Type 2 diabetes, heart attacks, high blood pressure, strokes, and depression, among other serious conditions. Desiring to take a nap in the daytime is also a sign of sleep apnea. In some cases, a sleepy driver may fall asleep behind the wheel while waiting at the red light due to sleep apnea. (FYI, this is not me. I’m too safety-conscious to fall asleep in the driver’s seat.)
The sleep doctor also says that a person should feel refreshed after sleep, without the need to take a nap in the daytime. White people suffer from sleep apnea usually because they are obese, whereas Asian people have greater chances of having sleep apnea even if they are slim.
It’s easy to explain why my Apple Watch frequently detects a blood oxygen level as low as 76% in the nighttime and just above 4 hours of sleep even when I have lain in bed for 8 hours straight. After a cessation of breathing, I have to gasp for air, readjust my breath, toss and turn, and move my legs, so unconsciously that I thought I was still asleep. My Apple Watch doesn’t think so –– it doesn’t count in any minute spent on non-sleep events. Kudos to Apple for making such an intelligent device. You don’t even have to purchase any sleep tracking app; the built-in Apple Health app can do the job adequately.
In a word, I’ll be prescribed a CPAP machine, 75% of the cost of which is covered by OHIP. My sleep doctor will follow up on this CPAP therapy on March 11, 2021.
Hopefully this will improve my sleep and overall health.