Sleep apnea is not easy to diagnose. But there are some hints from this thread about sleeping on your back, feeling tired through the day, and feedback from people who notice you stopping breathing. Anyway, I suggest you use the forum that Stephen suggested. Or, the forum on the websites I mentioned above at http://goutpal.net/forums/topic/found-this-interesting-read/#post-2662
You are right that sleep apnea can be a sole cause of gout for some people. But, for other gout sufferers, it is just a contributing factor.