avi123 wrote:Thanks Denial and TNT for the explanations. So it's all anatomical.
Hi avi, the reason for needing high pressures will be different for each individual, but I'd like to add that your anatomy can be influenced by disease and genetics. Both of those factors have contributed to why I needed moderate pressures like yours (original Rx = 11) even though I'm 5'4" and 120 lbs.
Even after my Chiari surgery, my Rx was 11. Then the CompSA diagnosis when even low CPAP pressures caused centrals. I was diagnosed with Hashimoto's thyroiditis about 2 years ago and put on a low dose of Synthroid. A recent PSG showed that most obstructions now resolved at low pressures (like 5). It's possible that the untreated thyroiditis was causing inflammation in my throat/tongue that was reduced with the medication. (Although oddly enough, my diagnostic AHI was slightly worse than before.) I still have OSA though due to a hereditary "small airway", potentially exacerbated by a moderately deviated septum. My mom also has "small airway" OSA and I bet my grandma did too - she was a very thin lady but her snoring could be heard miles away! Unfortunately she passed away from a massive heart attack before either my mom or I was diagnosed with SA, or else we would definitely have encouraged her to "PAP up" as well.