Diabetes happens to be the commonest cause of chronic kidney disease (CKD) and is most often characterised by increased leakage of protein into the urine. So you are advised to have 24-hour urine collection to quantify amount of protein leakage, if any. In addition, series of blood tests intended to rule out other causes of CKD including chronic nephritis (inflammation of kidneys) can help to rule out potential types or causes of CKD. Definite cause would be known only by doing kidney biopsy. Further, focus should remain on strict blood sugar and blood pressure control (target BP <130/80 mmHg) while avoiding exposure to potential kidney toxic medications including daily continuous intake of common pain medications like Brufen and Nimulid. These measures do help to prevent progressive weakening of kidney function over years. As part of managing CKD, you would need regular evaluation by series of blood tests and intervention for some of the common complications of CKD like kidney bone disease and anaemia. Lastly, your diet should be low in carbohydrates and saturated fat, should have low salt intake (3-4 grams/day) with daily protein intake of 55-60 grams.