Pull ups at night?!?!?!?

Ok, I am seriously at my wits end over this issue, and I just don't know what to do anymore. My son is 7 years old, and still needs to wear a pull up at night. He is such a sound sleeper that he just can not wake up when he needs to go to the bathroom. We have tried not letting him have anything to eat or drink after 7pm, but that did not work at all. He is so ashamed that he refuses to even try to sleep without wearing one now. Should I just leave the issue alone and see if he will outgrow the problem? Or should I continue trying to make him sleep without wearing one? My daughter was completely toilet trained at the age of 3, and that was 11 years ago. This is unfamiliar territory to me, but I have heard that boys can be more difficult to toilet train than girls. Maybe there is some truth to that statement. Does anyone have any suggestions that I could try? I would greatly appreciate any help that I can get. :)