What Causes Nocturia?

I have been starting to have Nocturia (but only one time around 5-6 am, and not everyday) for the last 3 months & I am afraid I might have diabetes. I have a BMI bigger than 33 (height 188 cm, weight 125 kg). My immediate family does not have diabetes but my grandmother (mother side) did have it. I don t have other symptoms (continuous thirst, excessive hunger or infection/slow heal of bruises, nor fatigue or weight loss). I am concerned since I develop the Nocturia, I might have diabetes (or early diabetes)