I find that the longer I can stay in a very aero position, the less weight that is on my hands. Just the opposite of what happens when you start sitting up and raising bars and such.
Never heard any associate it with fatigue specifically in the hands though. Usually people complain about numbness in their hands.
If you are getting on the older side of 50 then you might need to do some things to strengthen your grip and maintain the muscle you are losing in your hands and everywhere else.