5 Stages of Diabetic Nephropathy (Diabetic Kidney Disease)

There are 5 stages of Diabetic Nephropathy (Diabetic Kidney Disease):

Stage I: High Glomerular Filtration Stage.
The main features are the increase of Glomerular Filtration Rate (GFR) and the increase of size of the kidney. Diabetic patients depending on insulin have already these changes and at the same time the blood flow of the kidney and the glomerular capillaries perfusion and inside pressure will raise. The early stage of kidney affection is reversible and can be recovered after the treatment of insulin. There is no pathological damage in stage I.

Stage II: Normal Albuminuria Stage.
In this stage, urine albumin expelling(UAE) is normal (<20ug/min or < 30mg/24h ). After exercise, the UAE will increase and it can recover after rest. In stage II, there are already glomerular structure changes. Glomerular basement membrane(GBM) thickens and mesangium matrix increases and GFR is higher than normal level, GFR >150ml/min. Patients with glycolated hemoglobin >9.5%, GFR>150mL/min and UAE>30μg/min are more easier to develop to clinical Diabetic Nephropathy (Diabetic Kidney Disease).

Stage III: Early Stage Diabetic Nephropathy (Diabetic Kidney Disease).
The main manifestations are UAE is continuously higher than 20～200μg/min (30～300mg/24h). High filtration is probably one cause of continuous micro albunminuria. Of course long time poor metabolic control is also the cause. In this stage, the blood pressure will slightly rise. Lower the blood pressure can decrease part of the UAE. The thickening of GBM and the increase of mesangium matrix is more obvious. There are already glomerular diffuse changes and hyaline change of arterioles. The incidence in this stage is 16%.

Stage IV: Clinical Diabetic Nephropathy Stage.
The features of this stage are large amount of albuminuria, UAE> 200μg/min, or continuous urine protein > 0.5g/d. The blood pressure rises and there are slight microscopic hematuria and urine casts. With the loss of large amount of urine protein, hypoproteinemia and edema will appear. In this stage, GFR will decline by 1ml/min every month, but most patients don’t have high serum creatinine.

Stage V: Renal Failure Stage.
Once the continuous loss of urine protein develops to clinical Diabetic Nephropathy, the GBM will thicken widely, glomerular capillary lumens will become progressively narrow and there are more necrotic glomeruli. Therefore, the filtration function of the kidney will decline progressively and lead to Renal Failure. In the end, for most patients GFR <10mL/min, serum creatinine and blood urea nitrogen will increase accompanied by severe hypertension, hypoproteinemia and edema. These serious complications are always the cause of death for patients with Diabetic Nephropathy (Diabetic Kidney Disease).

Patients with Diabetes should pay closely attention to the stages of Diabetic Nephropathy (Diabetic Kidney Disease) and prevent the appearance of Diabetic Nephropathy.