There can be various causes for your leg cramps
and these causes could be either directly due to uncontrolled diabetes
and its complications or independently of diabetes.
Uncontrolled diabetes can cause diabetic neuropathy
,arteriopathy of Lower kegs,deficiency of sodium,potassium and magnesium due to loss of electrolytes etc.
Other reasons could be deficiency of VIT D,VIT B 12 and calcium.
What you need to do is to consult a diabetologist
,get yourself tested for above mentioned causes and get treated comprehensively,including meticulous control of blod sugar levels.