JohnBFisher wrote: the fact is there is more of a correlation in hereditary factors than in weight.
If you come across any of these studies again, I'd be interested in seeing them. I've seen several people post this, and I have yet to see a single study that shows that OSA causes weight gain more often than weight gain causes OSA. I'm not saying it isn't so, only that I have not seen this data (and it would be a tough study to do).And I've read more than one study that shows the obstructive sleep apnea leads to weight gain, not the other way around.
I've cited this powerpoint presentation about obesity and OSA before:
http://www.stanford.edu/~davesv/Weight%20&%20OSA.ppt
Some highlights:
Obesity is the most powerful risk factor for obstructive sleep apnea (OSA)
The presentation goes on to ask whether OSA can cause weight gain (it can), and has an interesting, albeit inconclusive, discussion about whether weight loss helps OSA.Potentially modifiable risk factors for OSA also include alcohol, smoking, nasal congestion, and estrogen depletion in menopause.
Data suggest that obstructive sleep apnea is associated with all these factors, but at present the only intervention strategy supported with adequate evidence is weight loss. ( Young et al. 2002)
Two things that I see crop up in discussions like this one here: (1) Thin people can have OSA so being overweight doesn't cause OSA, and (2) losing weight doesn't improve OSA, so it wasn't caused by the weight gain in the first place. Regarding #1... That thin people can have OSA does not mean that OSA isn't most often caused by being overweight (independently or in conjunction with other risk factors). I'm actually not sure if #2 has ever been stated explicitly as I can't think off the top of my head of even one person who has posted, "I lost all my excess weight and my OSA is the same as it was" (the fact that no one has posted that is an interesting topic in its own right). But even if it is true that losing weight doesn't cure OSA, it doesn't mean the excess weight didn't cause OSA in the first place, alone or in conjunction with other risk factors (e.g., any woman whose ever suffered stretch marks caused by pregnancy can attest to the fact that delivering the baby doesn't always "cure" the stretch marks, yet no one would argue that the pregnancy caused them in the first place.)
Now back to the OP... I agree with those who posted comments suggesting that it's really none of your boss' business. How does he know you have apnea? Is there evidence of your sleep disorder at work? If not and you've shared this personal information with him, why did you? Are you friendly with your boss? If so, your willingness to be open about your condition may have led him to believe that you're open to talking about it. So he's talking about it, and sharing his misinformation, biases, and unsolicited advice. If you don't like that, you need to change the terms of the relationship where he doesn't feel comfortable doing this. If he's a friend, you can talk to him privately and tell him how you feel. You probably do have legal rights, what with the "hostile workplace" business, but I can't advise you on that.