The recommendation (from Diabetes UK, Healthline etc) for a person with Diabetes an no other comorbidities is 10 x 8oz glasses a day (2L) for a Male and 8 x 2oz glasses a day (1.6L) for a female

A Dialysis patient should limit their fluid intake to 3 or 4 glasses a day or according to instructions from their Doctor

If you are on dialysis that is the more "urgent" issue to deal with

So no, not good for your blood sugar, but you kinda need your kidneys "today" and unfortunately, once dialysis starts the (statistical) life expectancy makes longer term blood sugar control a mute point