Weight isn't always an issue with sleep apnea. Very skinny people have apnea too. I am doing a sleep study Sat night again, they need to readjust my titration level since I have lost weight too. I always laugh at my neuro, he tells me to open my mouth wide, then tells me my mouth is too small...I always tell him he is the only person who ever tells me that!!!! The first thing he diagnosed with me was apnea and I laughed at him..never ever did I think I would suffer from apnea. I am not sure how much the machine helps me, but I do use it every night.