Diabetic nephropathy may take many years to develop. Filtering function of the kidneys is usually higher than normal in the first few years of diabetes.
Kidney disease stages - based on filtration rate
- At stage one, kidney has damaged slightly with normal or increase filtration at this beginning stage of kidney disease. Glomerular filtration rate (GFR) is more than 90 mL/min/1.73m2.
- At stage two kidney’s filtration, function usually remains normal during these periods. Glomerular filtration rate (GFR) is between 60-89 mL/min/1.73m2.
- At stage three, kidney’s function is moderately decreased with glomerular filtration rate (GFR) between 30-59 mL/min/1.73m2.
- At stage four, kidney’s function decreased severely with glomerular filtration rate (GFR) is between 15-29 mL/min/1.73m2.
- At stage five, kidney’s function is almost failed with glomerular filtration rate (GFR) is Less than 15 mL/min/1.73m2 and requiring dialysis or transplantation.
Kidney disease stages based on the urine protein level
Over years of diabetes, people who are developing kidney disease will have small amounts of the blood protein called albumin begins to appear in the urine. This is the first stage of CKD, called as microalbuminuria. The kidney’s filtration function usually remains normal during these periods.
When disease progresses, more albumins appear in the urine, this stage called by macroalbuminuria or proteinuria. The kidneys filtering function starts to drop slowly, and the body starts to retain various wastes as filtration falls. When kidney damage progresses, blood pressure rises as well that in turn affect kidney.
Kidney damage rarely happens within the first 10 years of diabetes, and usually takes 15 to 25 years for kidney failure to develop. For people with diabetes of more than 25 years without any sign of kidney failure has decreased risk of developing kidney disease.