It is estimated that 8 to 16% of the population worldwide suffer from CKD.
What is chronic kidney disease?
Chronic kidney disease (CKD), also known as chronic renal disease, is a condition that occurs when your kidneys don’t work as well as they should to excrete waste, toxins and excess fluid from your body.
CKD is characterised by a progressive loss of kidney function over time.
The end stage kidney disease (ESKD), end stage renal disease (ESRD) or kidney failure, may develop over many years or within only a few months. At this stage, you will require either dialysis or a kidney transplant.
Causes of CKD
Kidney disease is usually caused by other pre-existing health problems, which put pressure on the kidneys. Commonly, it is a combination of different health problems.
CKD becomes more common with increasing age (> 60 years with variations worldwide). Although older people are more likely to suffer from chronic kidney disease, it can be developed at any age.1
------------------------------------------------
Sources
1 https://www.kidney.org/news/monthly/wkd_aging (accessed 20.01.2021)
2 https://www.kidneyfund.org/prevention/are-you-at-risk/ (accessed 20.01.2021)
Stages of CKD
Defined by the level of the kidney function (glomerular filtration rate, GFR), there are five stages of chronic kidney disease. G 1 (GFR >= 90 ml/min/1.73 m2) is the earliest stage, while G 5 (GFR < 15 ml/min/1.73 m2) represents kidney failure. This stage is also called end-stage kidney disease (ESKD) or end-stage renal disease (ESRD). At this point, you have only about 10-15% of your kidney function left and a renal replacement therapy such as dialysis is necessary for survival.1
By definition CKD starts at a eGFR <60ml/min/1.73m2 - G 3. Most patients may not have any severe symptoms until their kidney disease is advanced.2 Endocrine/ metabolic derangements or disturbances in the water or electrolyte balance become visible only in later stages (G4+: GFR <30 ml/min/1.73 m2).
CKD stages
------------------------------------------------
Sources
1 National Kidney Foundation https://www.kidney.org/atoz/content/hemodialysis (accessed 04.01.2021)
2 National Kidney Foundation www.kidney.org/atoz/content/about-chronic-kidney-disease (accessed 03.12.2020)
Diagnosis
Since a person can have kidney disease without any symptoms, your doctor may initially detect the condition through routine blood and urine tests. Testing is the only way to know if you have CKD.
Urine test
A urine test is one type done to check the levels of substances called albumin and creatinine in your urine – they are put in relationship and expressed as the Albumin to Creatinine ratio, or ACR.
Proteins (albumin is of blood protein) usually do not appear in the urine and are therefore a marker of kidney damage. If this test is repeatedly “positive” for protein over a period of three months or more, it is a sign of kidney disease.
Blood test
The main test for kidney disease is a blood test. The test measures the levels of creatinine in your blood. Your physician uses your blood test results, plus other parameters like your age, size, gender and other factors to calculate how many millilitres of fluid your kidneys are able to filter in a minute.
This calculation is known as your estimated glomerular filtration rate (eGFR) and done through validated formulas.
Creatinine is a breakdown product of muscle cells. If a certain level of kidney disease is reached the blood creatinine levels correlates with kidney function.
In the lab, your blood will be tested to see how many milligrams of creatinine are in one deciliter of blood (mg/dl). Creatinine levels in the blood can vary, and each laboratory has its own normal range, usually 0.7 to 1.3 mg/dl (61.9–115 µ mol/L).1 If your creatinine level is only slightly above this range, you probably will not feel unwell, but the elevation might be a sign that your kidneys are not working at full capacity.
------------------------------------------------
Sources
1 MSD Manuals https://www.msdmanuals.com/professional/resources/normal- laboratory-values/normal-laboratory-values
(Accessed 03.12.2020)
Do you know potential symptoms of CKD?
Further diagnostics
Once CKD is identified, your doctor will try to find the underlying cause of the disease. This is important, since treating the cause can help to slow the progression of chronic kidney disease.
There are many different diagnostic techniques that can be used, for example imaging techniques (ultrasound, computed tomography, magnetic resonance imaging) and several different kinds of blood tests. In some cases, it may be necessary to perform a biopsy, i.e. to remove a tiny piece of the kidney to examine it under a microscope and see how much kidney damage has occurred.1
------------------------------------------------
Sources
1 https://www.kidney.org/atoz/content/about-chronic-kidney-
disease (Accessed 04.01.2021)
You want to track how you feel, what you eat or note down important appointments? Here you can download the basis for your own CKD diary.