There’s the crowd which says too much sugar when you’re young makes it more likely to get adult onset diabetes. If they’re right, and if arsenic-tainted juice figures in that, the sugar may be the link, rather than the arsenic itself or at least alone.
Much of the arsenic comes from pesticide IIRC and possibly usage of different pesticides could alleviate the problem. I don’t know why people scream about malathion, for example, but barely give a peep about arsenicals.
If it leads to obesity, yes, one type is called Maturity Onset Diabetes of the Young, MODY, otherwise it's usually just dental caries. Both of those types of diabetes are characterized by insulin resistance.