Diabetes and Muscle Cramps last night....

Potassium (K), 

A problem with muscle cramps can sometimes be a problem with the muscle not being able to function properly due to a lack of proper electrolite balance. Potassium (K),

Calcium (Ca), 

and Magnesium (Mg) are absolutely essential for a muscle to be able to properly fire....and to properly relax. 

If there is a lack of these minerals in the body, the muscle can temporarily lose the ability to relax and, therefore, cramps. 

Try taking K, Ca, and Mg suppliments regularly and see if that doesn't make a huge difference.

This could also be the effect of insulin resistance. I'm not sure of your weight or sugar intake, but if you have too much sugar or processed crap in your diet for a prolonged period of time, the body goes into what is called insulin resistance. Insulin is an anabolic hormone that also serves to store calcium and magnesium. Insulin resistance, by these means, can be a cause of not only muscle cramps

Read more: http://wiki.answers.com/Q/Why_do_you_get_leg_cramps_at_night#ixzz24koTLFQw