This article discusses research about the effect of sleep deprivation on fat cells. They studied young, healthy people - allowing some to sleep only 4.5 hours per night and the other to sleep 8 hours for a few days. They examined each groups fat cells and determined that the short sleepers had more resistance to insulin. They concluded that sleep deprivation may impair our fat cells' ability to respond to insulin, which may lead to diabetes.
These findings are interesting, but there are some problems with the conclusions, as pointed out in the article. For example, most people do not get only 4.5 hours per night, more like 6 hours. Do they have the same effect. Also, most do not deprive for only a few days, but for months / years. Does our body adapt and do the fat cells than have normal insulin sensitivity? More research is definitely needed.