Hello and hope you are doing well.
Diabetes can affect the kidneys and cause nephropathy. The earliest indication of this is microalbimnuria. The hyperglycemia produces increased matrix production and thickening of the of the glomerular basement membrane (GBM). This causes the nephropathy. This in turn causes systemic hypertension. To prevent further damage, he will have to take medications regularly and check his blood sugars to ensure it is in the normal range of 80-120mg/dl. Strict adherence to a diabetic diet and regular exercise will further help to reduce blood sugars. He will need regular follow up with his nephrologist.
Hope this helped and do keep us posted.
HI as you say is 50% I am guessing you must have had an egfr done that was only 50??? if this is so it puts him is stage three of chronic kidney disease. However, although an egfr is a good indicator of function, it should be repeated a couple of times to ensure this. ie if it remians low or is falling, then it is CKD. next step should be a renal ultrasound. Avoid any imaging that needs a contrast as this is potent for people with CKD - my neph told me this last week! I too have CKD now stage 4 and just had an ultrasound recently which confirmed . I do strongly suggest, if not for his kidney function but his diabetes that he should cease drinking!!! Although I also have CKD, it is not from diabetes, though it is not uncommon in diabetics , they are a high risk group. Go back to dr, request kidney function test be repeated and order a renal ultrasound. As he has diabetes and is in a high risk group, I would ask for a refer to a nephrologist.