People with high BMIs are not arbitrarily sent for sleep study. They are evaluated further to determine whether sleep study might be appropriate. It starts with height/weight. Then a tape measure around the neck. Run through a questionnaire evaluation and say "AHH" so the doctor can see how big your airway opening is. If all evidence supports the possibility of OSA, you will be requested to do a sleep study. There are several ways to avoid this altogether. Get your BMI under 35 is one. Another would be to find a different career. I explained above why OSA is found vastly more often in obese people than everyone else. It's not some study. It's logic.