Five Stages of Kidney Disease in Diabetes
Author: Ham Pato
The deterioration that characterizes kidney disease in diabetic patients occurs in clusters and around them. The glomeruli are the filtering units of blood from the kidneys. At the beginning of the disease, the filtration efficiency decreases and important proteins are lost from the blood in the urine. Medical professionals judge the presence and extent of incipient renal disease by measuring the protein content of urine. Later in the course of the disease, the kidneys lose the ability to remove blood waste products, such as creatinine and urea. By determining these blood products is not known how much has advanced kidney disease.
Symptoms related to kidney failure usually occur only in the later stages of the disease, when kidney function has decreased to less than 10 to 25 percent of normal capacity. For many years before it reaches that point, kidney disease in diabetes is a silent process.
The five stages of the disease
Scientists have described five stages of evolution of renal failure in diabetics.
Stage I. Increases the flow of blood through the kidneys, and therefore, clusters. This is called hyperfiltration. The kidneys are larger than normal. Some people stay indefinitely in stage I, others go to Stage II after many years.
Stage II. The rate of filtration remains elevated or near normal levels and the glomeruli begin to show damage. Appear in the urine small amounts of a blood protein called albumin. This is known as microalbuminuria. In these incipient stages may not be detected microalbuminuria in each test. However, with increasing the rate of loss of albumin from 20 to 200 micrograms per minute, the finding of microalbuminuria is more constant. (Normal albumin losses are less than 5 micrograms per minute.)
To detect microalbuminuria requires special tests. People with type 1 and 2 may remain in stage II for many years, especially if well controlled blood pressure and glucose concentrations in the blood.
Stage III. The loss of albumin and other proteins in the urine passes from 200 micrograms per minute and can be detected in urine flow analysis. These tests are generally performed by immersing indicator strips into the urine. At Stage III is sometimes called “clinical albuminuria” or “overt diabetic nephropathy. Some patients have hypertension. The glomeruli suffer further damage. The kidneys gradually lose the ability to filter waste and increase blood levels of creatinine and urea nitrogen. People with type 1 and 2 may remain in stage III for many years.
Stage IV. Known as “advanced clinical nephropathy. Glomerular filtration rate decreases to less than 75 milliliters per minute, large amounts of protein excreted in the urine and almost always have high blood pressure. The concentrations of creatinine and blood urea nitrogen rise even higher.
Stage V. The final stage is kidney failure. Glomerular filtration rate drops below 10 milliliters per minute and manifest symptoms of kidney failure.
These stages describe the evolution of renal disease in most people with type 1 diabetes with renal impairment. In type 1 diabetes, the average time between the onset of kidney disease and stage IV is 17 years. The average time to progress to kidney failure is 23 years. This development can occur more rapidly (5 to 10 years) in people with hypertension for which no treatment is received. If there is proteinuria in 25 years, the risk of developing advanced kidney disease begins to decrease. Type 1 diabetes accounts for only 5 to 10 percent of all diagnosed cases of diabetes, but is responsible for 30 percent of cases of kidney failure caused by illness.