My knowledge of this is little more than yours, but my understanding is most people use CPAP machines to cure sleep apnea (extreme snoring basically). I've never heard of someone using one as a sort of sleep-hack. I imagine the machine is fairly uncomfortable? Would be curious to hear more about this.
I assumed that the OP was saying as they'd mitigated the effects of their apnea they now managed on only 6hrs of sleep instead of 10 [ie 6h of good sleep is enough, 10h of poor sleep was what they were getting before].
The one you typically hear about that presents with extreme snoring is obstructive sleep apnea. It's pretty much as the name implies: sleep apnea caused by an obstruction. Your body tries to breath, but for a variety of potential reasons, your airway is obstructed. The snoring is your body's attempt at overcoming the obstruction.
Then there's central sleep apnea. With central sleep apnea, there's no obstruction blocking airflow. Your central nervous system just periodically... decides not to breath. Doesn't even attempt to contract the muscles necessary to intake or expel air. Then at some point, it... decides to start back up. There's no snoring or other loud noises involved like there is with obstructive sleep apnea.
They're both sleep apnea, and both have the same impact on the body if left untreated, but they present in almost complete opposite manners. Obstructive sleep apnea is loud because your body is trying real hard to do it's job. Central sleep apnea is generally pretty quiet, because its the absence of your body doing it's job. It just decided to take a little breather from it's typical life-sustaining duties, then (hopefully) after a ~10-30 second break it gets back to doing what it's supposed to do. The loudest you might hear is a bit of deep, heavy, or irregular breathing as it handles the backlog of oxygen needs that built up while it was on break.
I spent years being misdiagnosed with stuff like depression and hypertension, because I'm pretty much the exact opposite of someone at risk of obstructive sleep apnea (don't snore, not overweight, not old). It took paying for a home sleep test out of pocket and giving my physician the results before I finally got any traction from a doctor to explore that route. Turns out I have central sleep apnea, and treating that has been revolutionary on my life. I don't sleep through alarms anymore, I'm learning to love waking up early, I'm not mentally and physically drained at the end of the work day, and all kinds of little things.
You can order a home sleep test online for $150. And if you have an FSA, you can use your FSA dollars on it without even having to go through a doctor. If you're constantly dragging ass during the day, have a wonky sleep cycle, wake up randomly at night, or just happen to be curious. At that price, it's well worth taking a sleep test just to rule it out as a cause.
