Julie,
To answer your question here is what I believe - being overweight does not "cause apnea" in an absolute sense any more than being overweight "causes cancer". Thinking that would be to make the mistake often referred to as the fallacy of the single cause (
https://en.wikipedia.org/wiki/Fallacy_o ... ngle_cause). However being overweight can be a contributing factor, that increases an individuals risk of developing apnea. This seems to be overwhelmingly supported by current research. For instance:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3021364/
Obesity is considered a major risk factor for the development and progression of OSA.8,19,20,27,28 The prevalence of OSA in obese or severely obese patients is nearly twice that of normal-weight adults.....It is possible that obesity may worsen OSA because of fat deposition at specific sites. Fat deposition in the tissues surrounding the upper airway appears to result in a smaller lumen and increased collapsibility of the upper airway, predisposing to apnea
And research also suggests that apnea can be a contributing factor for obesity:
However, the relationship between OSA and obesity is complex. Although there is compelling evidence showing that obesity, as well as visceral obesity, may predispose to OSA, and that losing weight results in OSA improvement, recent studies suggest that OSA may itself cause weight gain
It is humorous that a few people have angrily declared that "being overweight does not cause apnea", yet turn around and state "apnea does cause being overweight". Both are contributing factors and it's not terribly uncommon for causal relationships to work in a circular direction. It's one of the most common questions that comes up in studies, for instance people with depression are more likely to have sleep problems and people with sleep problems are more likely to have depression. Sometimes scientists are able to determine the causal relationship is more strong in one direction, sometimes not.
My purpose in running this poll was curiosity, to see what the distribution was like here on the forum, nothing more. You know what made me curious? The fact that I think I have apnea, so I'm researching everything I can about it. Hmm....I wonder if apnea causes curiosity?