My god damn CPAP machine does this. Insurance required the modem in order for them to pay for it.
If you are having issues because of physically fixable issues there are surgeries that can help (I had 2 things fixed). Most of the time however its just being fat and physical. Loosing the weight helps and the effect can be tracked in the data the CPAP collects. The doctor can then use the data to adjust then pressure down.
I am speaking from experience. My pressure setting has dropped as I took off the beer gut. This time next year I will likely be able to be done with it.