Chronic Kidney Disease

By: coconut dreams

Imagine that half the worlds population older than 70 has chronic kidney disease (CKD). This is the reality suggested by new international guidelines adapted in 2012 (International Society of Nephrology). The purpose of this essay is to define chronic kidney disease and identify its pathogenesis, clinical manifestations, etiology, epidemiology, and current treatments.

Kidneys filter wastes and excess fluids from blood, which are then excreted in urine. However, gradual loss of kidney function occurs when a disease or condition impairs kidney function, causing kidney damage to worsen over several months or years, leading to CKD. CKD is similar to a malfunctioning lint catcher in a dryer – the lint catcher catches lint to ensure the dryer runs properly and efficiently. However, if the lint catcher is not properly cleaned after each use, then lint and other debris continues to build up, decreasing the dryers efficiency, leading to potential explosion or malfunction. Similarly, CKD causes the buildup of fluid and waste products in the body, which affects other body systems and functions, typically leading to other issues, such as high blood pressure and low blood cell count (NIH).

According to the results of the 1999-2004 National Health and Nutrition Examination Survey (NHANES), in the United States alone, an estimated 26 million people, approximately 13% of the adult U.S. population, have CKD. This is approximately a 13% increase from the estimated 20 million adults affected in 1994. In this study, adults older than 20 years were randomly surveyed and kidney function was tested. Of those surveyed, only 11.6% of men and 5.5% of women were aware that they had kidney disease (moderate stage 3). Awareness increased to 42% among those with severed Stage 4 kidney disease. The NHANES study and a study conducted by J. Coresh et al (2007) also found that although racial and ethnic minorities do not appear to have an increased prevalence of CKD in the U.S. compared with non-Hispanic whites, the risk of progression from CKD to ESRD is higher for African Americans, Hispanics, Pacific Islanders, and Native Americans. The reasons for this disparity are unclear and are currently under investigation.

Despite the increased prevalence of CKD, it continues to be under-recognized by both healthcare providers and patients, especially during the early stages when patients are generally asymptomatic. According to Andrew S. Narva, M.D., F.A.C.P., a kidney specialist at the National Institute of Health, he states “kidney disease is often silent until late stages, but if we can find it early we can do a lot to prevent kidney failure” (NIH). Currently there is no cure for CKD. However, depending on the underlying cause, some variations of kidney disease can be treated. Efforts are primarily focused on managing and slowing the progression through various medical treatments, procedures, and lifestyle changes (NIH).

Diabetes and high blood pressure are the two most common causes of CKD. According to Paul Eggers, Ph.D, director of kidney disease epidemiology at the National Institute of Diabetes and Digestive and Kidney Diseases, he states that “increases in diabetes, hypertension, obesity, and the aging U.S. population explain at least some of the increase, [however] we don’t know what may be responsible for the rest” (NIH). However, there are many other diseases and conditions that can damage the kidneys, which may significantly contribute to the development of CKD, including autoimmune disorders, congenital birth defects, such as polycystic kidney disease, reflux nephropathy (the backward flow of urine into the kidneys), glomerulonephritis (inflammation of the glomeruli, structures responsible for filtering blood in the kidneys), and pyelonephritis (inflammation of the kidneys) (Mayo Clinic).

According to Andrew S. Narva, M.D., F.A.C.P., a kidney specialist at the National Institute of Health, he recommends that those with diabetes, high blood pressure, or a family history of kidney problems should be screened for kidney damage with routine blood and urine tests because they are at higher risk for developing CKD. Narva, along with other medical professionals also recommend medications, such as angiotensin converting enzyme inhibitor or angiotensin receptor blockers to address heart complications, and dietary modifications, including low protein and salt diets. The Mayo Clinic recommends those afflicted with CKD to ask their health care providers if they also require cholesterol-lowering medication because those with CKD often experience high levels of cholesterol, which can increase the risk of heart disease (Mayo Clinic). The Mayo Clinic also recommends patients investigate whether or not they should be taking diuretics, or water pills. Often those with CKD retain fluid, which causes swelling in the legs. It may also cause high blood pressure.  These medications, which relieve swelling by increasing urination help to maintain fluid balance (Mayo Clinic). Finally, the Mayo Clinic recommends low protein diets as this would be one option that may help reduce the amount of work the kidneys must do, helping preserve them (Mayo Clinic).

Over time, CKD will overwhelm these medications and treatments and patients will develop end-stage renal disease (ESRD), or complete or near-compete kidney failure. ESRD occurs when the kidney’s can no longer keep up with waste and fluid clearance on its own. At this point, dialysis or a kidney transplant is needed. Dialysis is the process of removing waste products and extra fluid from the blood. There are two types of dialysis. Hemodialysis utilizes a machine to filter waste and excess fluids from the blood. Peritoneal dialysis utilizes a catheter (a thin tube) that is inserted into the abdomen and fills the abdominal cavity with a dialysis solution that absorbs waste and excess fluids. After a period of time, the dialysis solution drains from the body, carrying the waste and excess fluid with it. A kidney transplant is a surgical procedure that involves the removal of the diseased kidney and replacing it with a healthy kidney from a donor (Mayo Clinic).

Ultimately, successful management of CKD depends on optimal management of common comorbid conditions, such as diabetes and cardiovascular disease, patient education, and a multidisciplinary approach to disease management that utilizes dieticians and social workers, in addition to physicians, is crucial to the successful management of CKD (University of Michigan). 

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J. Coresh et al. "Prevalence of Chronic Kidney Disease in the United States," Journal of the

American Medical Association, November 7, 2007; 298(17): 2038-2047.

KDIGO 2012 Clinical Practice Guideline for the Evaluation and Management of Chronic

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