no matter what kind of bars, if you keep your hands in the same place, you can get muscle tension that restricts the blood flow and your hands start to go to sleep. That's the same thing for anybody.
The answer is not to give up your favorite bars, or even to get gloves unless you want them...all you need to do is to remember to take a hand off the bars and move it around every 15 or 20 minues or so. Learn what kind of movements work best for you (I like to just put my arm behind my back, but that's because my tension is in my shoulder) but you have to remember to stretch a little every so often before your hand goes numb