I have a question about Sleep Apnea Testing.?

My boyfriend is a truck driver, who worked for a company for 14 yrs. Now they say it is mandatory that ALL drivers be tested for sleep apnea. So far, they've only sent overweight drivers, (he's in that category) to be tested. My boyfriend does snore, but then again, who doesn't. I'm sort of a night owl, and I've heard and seen him sleep. The testing center said that he stops breathing while sleeping. I don't believe this to be true. He never had trouble sleeping before. Now all of a sudden, they say he has sleep apnea. Not only him, but ALL the other overweight drivers at his company. How is it possible that ALL the drivers have sleep apnea? Why weren't the average weight drivers tested? Is this a weight discrimination to replace overweight drivers?