I find I have the opposite problem. Before diagnosis I frequently had calf cramps, toe cramps, and full bladder waking me up before I needed to. Now, on 4x500g Metformin, I very rarely get any problem, and sleep right through till a civilised hour. I realize I am lucky in this respect.
Leg cramps could be due to electolyte inbalance. If you are on an LC trpe of diet, then this may be reducing your sodium levels, and I was advised to increase salt in the early stages of LCHF to compensate. Also some BP meds and blood thinners can act as diuretics. Check the meds leaflets.