Deterioration of kidney function is one of the many unhappy consequences of
diabetes. Excellent dietary control and exercise should prevent most of the
suffering and expense involved in kidney failure. The deterioration in the
kidneys of diabetics takes place in and around the glomeruli, the
Early in the disease, kidney filtering efficiency diminishes and proteins in
the blood are lost to the urine. Later in the disease, the kidneys lose their
ability to remove waste products, such as creatinine and urea, from the blood.
Symptoms related to kidney failure usually occur only in late stages of the
disease, when kidney function has diminished to less than 25 percent of normal
capacity. For many years, the kidney disease of diabetes is a silent process.
There are five stages in the progression of kidney disease:
Stage I. The kidneys are larger than normal.
Stage II. The rate of filtration remains elevated or at near-normal levels,
but the glomeruli begin to show damage. Small amounts albumin leak into the
urine-- microalbuminuria. As the rate of albumin loss increases from 20 to 200
micrograms per minute, microalbuminuria becomes constant. Normal losses of
albumin are less than 5 micrograms per minute. Patients may remain in stage II
for many years, especially if they have normal blood pressure and good control
of their blood sugar levels.
Stage III. Increased loss of albumin and other proteins in the urine. Protein
losses over 200 micrograms per minute can be detected by urine dipstick methods.
Some patients with kidney disease develop high blood pressure. The glomeruli
suffer increased damage. The kidneys progressively lose function and blood
levels of creatinine and urea-nitrogen rise.
Stage IV. Advanced l nephropathy; the glomerular filtration rate decreases to
less than 75 milliliters per minute, large amounts of protein pass into the
urine, and high blood pressure almost always occurs. Levels of creatinine and
urea-nitrogen in the blood rise further.
Stage V. End Stage Renal Disease. The glomerular filtration rate drops to
less than 10 milliliters per minute. Symptoms of kidney failure occur. For
people with poorly controlled DB2, the average length of time required to
progress from onset of kidney disease to stage IV is 17 years. The average
length of time to progress to ESRD is 23 years. Progression to ESRD may occur
more rapidly (5-10 years) in people with untreated high blood pressure. If
proteinuria does not develop within 25 years, the risk of developing advanced
kidney disease decreases; 60 percent of people with diabetes who develop ESRD
have DB2. According to the US National Kidney and Urologic Diseases Information
Clearinghouse, each year in the United States, more than 50,000 people are
diagnosed with end-stage renal disease (ESRD), the final stage of a slow
deterioration of the kidneys. ESRD patients undergo either dialysis or
transplantation. Most Canadian and U.S. citizens who develop ESRD are eligible
for funded care.