|Image Source: intelihealth.com|
Renal failure (kidney failure) is caused primarily by chronic high blood pressure (hypertension) over many years. Hypertension is the second major cause, after diabetes, of end stage renal disease (ESRD) and is responsible for 25–30% of all reported cases. In addition, many people with diabetes also have hypertension, thus high blood pressure plays an even larger role in kidney failure.
About 398,000 people were diagnosed with end-stage renal disease in 1998. Of these, about 83,000 had hypertension and about 133,000 had diabetes. That same year, approximately 63,000 people with ESRD passed away. Most people with ESRD have had symptoms for a long time and may have had kidney disease (nephropathy) for as many as 20 years or more prior to experiencing kidney failure.
It is believed that most cases of hypertension leading to kidney failure have a genetic element. Finding a genetic link is complicated by the fact that nearly half of all people with renal failure have three or more serious disorders, such as diabetes. Animal studies have been done to find genetic linkages to hypertension and kidney failure, but genetic studies on humans are in their infancy. A recent breakthrough came in a study of African American subjects with hypertensive end-stage renal disease. Researchers found a significant association between severe hypertension and mutations on the HSD11B2 gene. This is a gene that plays a role in sodium retention and related factors. Their data suggested that the 16q22.1 chromosome region was the location of the mutation.
In another study, researchers studied an Israeli family of Iraqi-Jewish origin whose members suffered from hypertension and renal failure. The researchers found a genetic locus at 1q21 that was autosomal dominant. They also hypothesized that the gene encoding atrial natriutetic peptide receptor-1 (NPR1) was the disease gene that led to the hypertension/renal failure.
Other families with high rates of hypertension have also been studied. For example, researchers observed a family of Old Order Amish in Lancaster, Pennsylvania and found a genetic link for hypertension to chromosome 2q31-34. The subjects were not experiencing kidney failure, thus, further study would be needed to determine if the identified genetic locus also coded for ESRD.
What Are the Symptoms of Kidney Disease?
The symptoms of kidney disease include:
- High blood pressure.
- Decrease in amount of urine or difficulty urinating.
- Edema (fluid retention), especially in the lower legs.
- A need to urinate more often, especially at night.
As with high blood pressure, you may not realize that you have kidney disease. Certain laboratory tests can indicate whether your kidneys are eliminating waste products properly. These tests include serum creatinine and blood urea nitrogen (BUN); elevated levels of either can indicate kidney damage. Proteinuria, an excess of protein in the urine, is also a sign of kidney disease.