BMI is a contributing factor, but so is neck and throat anatomy, regardless of weight. There are plenty of non-overweight people who have sleep apnea. And treatment sucks because so many doctors don't know anything past "you should lose weight".
Ok, what about looking at nose shape of diaspora that have historically (multigenerationally) high BMI? Not an expert but might suggest Inuit, some Pacific Islanders, Māori, west Africans maybe. How are their noses shaped and anything that might help with apnea?
