Diabetes injures the small blood vessels in the body, and when the blood vessels in the kidneys are injured, your kidneys cannot clean your blood properly. Your body will retain more water and salt than it should, which can result in weight gain and ankle swelling; waste materials will build up in your blood. Diabetes also may cause damage to nerves in your body. This can cause difficulty in emptying your bladder. The pressure resulting from your full bladder can back up and injure the kidneys. Three types of treatment can be used once your kidneys have failed: kidney transplantation, hemodialysis and peritoneal dialysis.
For more information see Diabetes and Kidney Disease - National Kidney Foundation.