Chronic kidney disease (CKD) is a gradual loss of kidney function over a period of months or years. Damage to kidney tissue in CKD is irreversible and progressive even if the cause is eliminated. Causes may vary and typically there are no symptoms in early disease. Symptoms usually appear when more than 70 percent of the kidney functions have been lost. Therefore, waiting until symptoms appear is not the right approach in CKD. It is roughly estimated that there are more than 60,000 CKD patients in Sri Lanka, out of which 5,000 are in advanced stages.
Kidneys have multiple functions which are essential for life. They regulate blood volume by controlling urine production. Excretion of waste products and foreign substances from the body is done by the kidneys. Blood pressure, ionic composition of blood, and blood acid–base regulations are also controlled by the kidneys. Red blood cell production and Vitamin D synthesis are supported.
In chronic kidney disease all of the above functions get impaired. This will lead to variable symptoms experienced by patients. There could be swelling due to failure of water excretion. Commonly, the face and ankles swell up. In addition to the visible swelling, internal organs are also affected. This results in shortness of breath due to wet lungs.
High blood pressure is a feature of kidney failure as regulation by the kidney is lost. Key ions in the body, including potassium, sodium and chloride, are basically controlled and even a mild alteration of these will create an unfavourable environment for the body. High potassium levels can cause heart rhythm disturbances and muscle weakness, while low sodium is associated with confusion, and low calcium levels cause muscle weakness. Maintaining the body’s acid–base balance is essential to maintain cell functions optimally. The hormone erythropoietin, which is synthesised by kidney cells, stimulates bone marrow to produce red cells to maintain haemoglobin. Lack of this hormone results in anaemia. A key step in Vitamin D synthesis happens in the kidney and patients suffering from kidney failure will have Vitamin D deficiency.
A wide range of factors can damage kidneys gradually to cause CKD. Some agents can damage to blood vessels, some can damage the supporting tissues of kidney cells, and some can directly damage kidney cells. Pathways of damaging kidney cells may vary depending on the aetiology, but the end result is death of kidney cells and scarring. This is the reason why damaged kidneys cannot be regenerated.
Diabetes is the Number One cause of chronic kidney disease anywhere in the world. When the prevalence of diabetes goes up in a region, the number of CKD patients also goes up. Elevated blood sugar levels damage the small blood vessels in the body. This affects many organs including the kidneys, eye and nervous system. The initial feature is mild protein leak in urine, which can only be detected by special urine tests and can be missed in routine tests. This is called the micro-albuminaemic stage of diabetic kidney disease. Then it progresses to the high leaking stage and it is readily detected by simple urine tests. At this stage, patients observe that their urine is frothier than earlier. Following this stage, the kidney functions start to deteriorate gradually with obvious biochemical markers of kidney damage. Poorly controlled blood sugar levels will expedite the damage and, in patients with high blood pressure, will cause faster deterioration. Kidney damage in diabetes patients will be enhanced by recurrent infections anywhere in the body, certain antibiotics used for them, and painkillers.
Chronic kidney disease in children will impair their growth. CKD patients will experience the following problems: excessive water in the body causing swelling and shortness of breath, confusion and weakness due to accumulation of toxic substances in the body, heart rhythm disturbances due to salt imbalances, uncontrollable high blood pressure, anaemia due to erythropoietin deficiency, and skeletal problems due to low Vitamin D and calcium levels. Further, CKD patients will commonly experience loss of appetite, lack of sleep, body aches and pains, darkening of skin and itching caused by accumulation of various metabolic waste products in excessive amounts due to lack of filtration into the urine.
Treatment of CKD involves correction of these abnormalities. Calcium and Vitamin D can be supplemented and blood acidity can be neutralised by drugs. Erythropoietin can be given in the form of injections to improve the haemoglobin. Lack of sleep, itching and appetite can be helped with certain medicines.
 Swollen ankles are a symptom of CKD. |
But, these symptoms and problems cannot completely be treated by medicines. The only way is to get the functions of the kidneys done by some other way such as by transplanting a new kidney. Kidney transplant will normalise most of the ill effects caused by CKD and will reverse most of the negative effects of CKD patients. But, dialysis will do some of the tasks of the kidneys, such as cleaning of toxins from the blood and removal of excess water from the body. Dialysis is a basic treatment where the toxins are removed mechanically from the body. Two types of dialysis is available, i.e., haemodialysis and peritoneal dialysis. In the former, a patient’s blood is cleaned by a machine twice or thrice a week at a dialysis centre. Each session is of three to four hours’ duration. Peritoneal dialysis (PD) in contrast, is done at home and is a continuous process. The best treatment for CKD is a kidney transplant which will give patients more freedom to lead a normal life.
Diagnosis of CKD is not always straightforward. In high-risk patients, screening will help early diagnosis which in turn will help to improve the outcomes. Main tools for diagnosing CKD include urine tests and blood biochemistry for creatinine, urea and potassium levels. Imaging of kidneys by ultrasound scanning might show altered kidney tissues and sometimes, small shrunken kidneys. Complications of CKD are detected by many other directed urinary, biochemical and radiological investigations. End-stage kidney disease is irreversible and complete impairment of kidney function, which needs kidney replacement to maintain life. Scientifically, we can calculate the existing amount of kidney functions; when it is less than 10, we can call it end-stage kidney disease (normal is 80–120).
There are few golden rules for preventing CKD and end-stage kidney disease. These include proper control of diabetes and high blood pressure. Awareness and regular screening of high-risk groups for CKD is a must. High-risk groups include all diabetics, hypertensive people who live in areas where kidney disease is endemic, those who have positive family history of CKD, and people with any other kidney disease such as kidney stones.
To maintain the health of the kidneys in general, we should consume enough pure water, treat blood sugar and high blood pressure properly, avoid high salt content in diet, avoid over-the-counter medication, avoid smoking, maintain a healthy weight, and have an active lifestyle with regular physical exercise.
This year’s theme for World Kidney Day is ‘Kidneys and women’s health’. There are a few conditions which specifically affect women’s kidneys. These include complications in pregnancy and autoimmune type of kidney diseases. Kidney infections are more frequent in females than in males. CKD reduces the fertility of women and also results in poor foetal and maternal outcomes in pregnancy. Certain complications of pregnancy can lead to CKD and timely diagnosing and management of these complications can prevent permanent damage. Public awareness, prevention, early detection, and timely treatment are the factors that promote the health of kidneys in the case of women.
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