Risk Factors of
Kidney Disease
Over 300,000 patients have end-stage renal disease (ESRD) in the United States. By 2010 there probably will be about 650,000 patients with ESRD in the United States, if the same rate of increase continues.
End-Stage Renal Disease
Kidney failure means loss of some (but not all) of the filtration capacity of the kidneys, which can be caused by:
Fall in blood pressure
Blockage of the blood circulation to the kidneys
Blockage of urine outflow
Disease of the kidneys themselves
When about 2/3 of filtration capacity is lost, symptoms of kidney failure begin to appear. When 7/8 or so is lost, survival depends on either starting dialysis or transplanting a new kidney. This is called end-stage renal disease (ESRD)
Acute kidney failure can be caused by drugs toxic to the kidneys, by a severe reduction in kidney blood flow (for example, during surgery), and by many other causes.
Chronic kidney failure is generally not reversible and often gets progressively worse. In other words, a small scarred kidney is not going to grow back into a normal one, no matter what. There is no such thing as remission of chronic renal failure. However, arresting the progression of the disease is a possibility.
Uncontrollable Risk Factors
Genetic Predisposition
Men are slightly more susceptible to kidney failure than women.
African Americans comprise 30% of those with ESRD, almost twice their frequency in the population at large.
Native Americans and Pacific Islanders are also particularly susceptible.
At higher risk if you're first-degree relatives of people on dialysis.
At higher risk if you have polycystic kidney disease due to genetic defects.
One of the most common causes of renal disease is glomerular disease (glomerulonephritis or glomerulosclerosis) which includes a list of disorders with varying causes.
The multiple corrective operations that are needed for kids who have difficulties with urinary drainage may cause kidney failure.
Risk Factors You May Influence
Patients with diabetes (insulin-dependent or non-insulin-dependent) may get kidney failure after a decade or more of suffering from this disease.
Undertreated or untreated, hypertension can lead to kidney failure. It is widely held that African Americans are more susceptible than whites to kidney disease from hypertension.
Potassium deficiency is another cause of kidney failure, though it is uncommon. Note that chronic diarrhea or overuse of laxatives can induce chronic potassium deficiency and renal failure.
NSAIDs and other OTCs have the potential to cause kidney failure, when taken long term.[7]
A recent review lists 17 dietary supplements that have been associated with direct kidney injury, though in a very limited numbers of cases.
Take lithium chronically can increase the risk of kidney failure. Lithium is widely used for the treatment of bipolar disorder.
Back pressure can develop when the outflow of urine from the body is partially obstructed. This back pressure may distort the shape of the kidneys and diminish their function. In some cases, complete urinary tract obstruction can develop and acute renal failure may occur. By far the most common cause of urinary tract obstructions is enlargement of the prostate in men.
Obesity is one of the most frequent risk factors for progressive chronic kidney disease in the general population.
From an epidemiologic point of view, the association between BMI and the incidence of ESRD has been convincingly established in population-based studies in Japanese men [2] and in American people [3].
Conclusions
Kidney failure, unlike disease of many other organs, rarely leads to symptoms that point to the site of the problem (i.e., kidney). For example, pain in the kidney region is an unusual complaint. Sometimes patients with chronic kidney failure never notice changes in their urination (i.e., changes in the volume, color, appearance, or odor of the urine).
It is very easy to find out whether you have protein in your urine, which is an early sign of kidney disease. Protein in the urine can be detected simply by holding a paper strip (Uristrip and others) in the urinary stream. These strips are available without a prescription and can be found in or ordered by your local pharmacy. A change in color may indicate protein or glucose. However, the transient appearance of protein in the urine can also be caused by vigorous exercise, infection, fever, or very high blood sugar. People with diabetes can and should test their urine for protein at least once a month.
As noted above, physical symptoms are not a reliable guide to judging the severity of kidney failure or to the rate which kidney function is decreasing. Lab measurements are the key:
Serum albumin level (an index of protein nutrition) -- 60% of patients entering dialysis nationwide in the US are malnourished, as shown by their subnormal serum albumin levels.
Serum creatinine level, which measures patient's level of kidney failure. It is the most commonly used screening test for early kidney impairment.
Serum urea level, which is a useful marker for kidney failure, but it must be interpreted in the light of known protein intake.
Serum Cystatin C level, which is more reliable than creatinine in early renal failure. It is also more reliable in people with liver disease, in whom creatinine levels become particularly unreliable.
Glomerular filtration rate, which is the only good measure of the amount of kidney function remaining.
References
"Coping with Kidney Disease" by Mackenzie Walser, M.D. and Betsy Thorpe
Iseki K, Ikemiya Y, Kinjo K, et al. Body mass index and the risk of development of end-stage renal disease in a screened cohort. Kidney Int 2004;65:1870-1876.
Hsu CY, McCulloch CE, Iribarren C, et al. Body mass index and risk for end-stage renal disease. Ann Intern Med 2006;144:21-28.
Two simple tests to check for kidney disease:
A urine test for albumin, a type of protein: protein in the urine is one of the earliest signs of kidney damage. When there is too much protein in the urine, it means that the kidneys’ filters are damaged and are starting to leak protein.
A blood test for creatinine: creatinine is a waste product (from muscle metabolism) that is removed by the kidney. Creatinine level is used to calculate your estimated glomerular filtration rate (eGFR). The eGFR reflects how well the kidneys are filtering wastes from the blood.
Each day, 1-2% of muscle creatine is converted to creatinine. Men tend to have higher levels of creatinine than women because, in general, they have a greater mass of skeletal muscle. Increased dietary intake of creatine or eating a lot of meat can increase daily creatinine excretion.