The kidneys of young humans filter approximately 180.0 liters of blood daily, which undergo a remarkable process of reabsorption and to a much lesser extent, secretion of unwanted metabolic chemicals that are ultimately removed in a daily urine volume of approximately 1.5- 2.5 liters. Each kidney has approximately 1,000,000 units which individually combine to make up a measure of overall kidney function called the glomerular filtration rate (GFR). Kidneys are also responsible for the production of hormones such as active vitamin D, which is essential to maintaining healthy bones throughout life and Erythropoietin (EPO) which is essential for stimulating the bones to produce sufficient numbers of red blood cells to carry out the process of delivering oxygen to all organs of the body. Chronic Kidney Disease (CKD) as it progresses from stage 3 through stage 5 and end stage kidney disease (ESKD), requiring dialysis or kidney transplantation, affects the above organs resulting in abnormal bone structure and low red blood cell counts which limit oxygen carrying capacity of the blood, resulting in loss of energy and fatigue. Failure of the ability to eliminate accumulated metabolic and waste products, cause loss of appetite, nausea and progressive weight loss; failure to excrete the daily load of salt and water results in hypertension and fluid retention. These processes are usually painless; kidney disease is regarded as a silent killer.
Kidney function is assessed clinically by using the blood level of a body chemical, creatinine that is produced in the liver and more than 90% removed by the kidneys, to derive a measure of the overall filtration function off all functioning units (nephrons), called the estimated glomerular filtration rate (eGFR), which is indexed to a standardized body surface area in a steady state. Chronic kidney disease applies to stage 3 or beyond in the staging system
The level of increasing amounts of protein leaking from the kidneys in the urine along with the stage of CKD increases the rate of progression to end stage kidney failure (ESKD) and increases the risk of premature death from heart attacks, heart failure, strokes, serious infections and death in those with stage 3 or beyond. Approximately 10-15 percent of persons with stage 3 CKD survive to reach dialysis and kidney transplantation. Deaths in CKD patients are approximately 10-20-fold higher than in non-CKD populations.
The World-wide Impact of Chronic Kidney Disease
The most recent global survey published in 2022, estimates that more than 10% of the world population have CKD, which amounts to some 800 million individuals. It disproportionately affects persons older than 45 years, females, ethnic minorities, indigenous peoples and those with diabetes and high blood pressure (hypertension). In the United States more than 1 in 7 adults have Chronic kidney disease-approximately 37 million persons; there are 800,000 persons at end stage kidney disease (ESKD) with 71% on dialysis and 21% transplanted. The risk for ESKD fir diabetes is 1 in 3 and for hypertension, 1 in 5. African Americans have a 3-4-fold greater risk of ESKD and make up approximately 25-30% of that population. In 2013 chronic kidney disease was ranked at 19 as a cause of death worldwide; in 2017, it ranked 12th; it is predicted to rank at 5 by 2040.
Causes of Chronic Kidney Disease
The Economic burden of chronic kidney disease
The annual cost of providing dialysis treatment averages $97,000.00 per patient; the cost for kidney transplantation can range between $ 150,000.00 and $ 450,000.00 per patient depending on the inclusion costs for transplant work up, organ procurement and the first 4-6 months of treatment. After the first-year transplant costs average $ 25,000.00-$30,000.00 per year for medications.
Dialysis patients take an average of 9-12 medications daily for hypertension, diabetes, high cholesterol, heart disease, vitamin supplementation, medications for mineral bone disease and Erythropoietin (EPO) for reducing the need for blood transfusions to counter the low red blood cell counts (anaemia). Monthly out of pocket expenses can approach $2,000.00 without third party coverage. Only a minority of dialysis patients are able to remain gainfully employed so the financial burden falls on the family. Successful kidney transplantation provides the optimal treatment with clinical functional improvement and return to productive life. 5 year survival on dialysis in the United States is 41%; in Europe, 48% and in Japan, 60%. Dialysis in the United States is funded by Medicare/Medicaid; Europe and Japan have universal health care systems that fund ESKD/Transplant care.
Emerging Issues in chronic kidney disease