CHRONIC KIDNEY DISEASE DEFINITION Chronic kidney disease includes conditions that damage your kidneys and decrease their ability to keep you healthy by doing the jobs listed. If kidney disease gets worse, wastes can build to high levels in your blood and make you feel sick. You may develop complications like high blood pressure, anaemia (low blood count), weak bones, poor nutritional health and nerve damage. Also, kidney disease increases your risk of having heart and blood vessel disease. These problems may happen slowly over a long period of time. Chronic kidney disease may be caused by diabetes, high blood pressure and other disorders. Early detection and treatment can often keep chronic kidney disease from getting worse. When kidney disease progresses, it may eventually lead to kidney failure, which requires dialysis or a kidney transplant to maintain life. The disease is called “chronic” because the damage to your kidneys happens slowly over a long period of time. This damage can cause wastes to build up in your body. CKD can also cause other health problems. The kidneys’ main job is to filter extra water and wastes out of your blood to make urine. To keep your body working properly, the kidneys balance the salts and minerals—such as calcium, phosphorus, sodium, and potassium—that circulate in the blood. Your kidneys also make hormones that help control blood pressure, make red blood cells, and keep your bones strong. Kidney disease often can get worse over time and may lead to kidney failure. If your kidneys fail, you will need dialysis or a kidney transplant to maintain your health. The sooner you know you have kidney disease, the sooner you can make changes to protect your kidneys. FACTS ABOUT CKD 30 million American adults have CKD and millions of others are at increased risk. Early detection can help prevent the progression of kidney disease to kidney failure. Heart disease is the major cause of death for all people with CKD. Glomerular filtration rate (GFR) is the best estimate of kidney function. Hypertension causes CKD and CKD causes hypertension. Persistent proteinuria (protein in the urine) means CKD is present. High risk groups include those with diabetes, hypertension and family history of kidney failure. African Americans, Hispanics, Pacific Islanders, American Indians and Seniors are at increased risk. Two simple tests can detect CKD: blood pressure, urine albumin and serum creatinine. Recent research suggests that 1 in 10 of the population may have CKD, but it is less common in young adults, being present in 1 in 50 people. In those aged over 75 years, CKD is present in 1 out of 2 people. However, many of the elderly people with CKD may not have ‘diseased’ kidneys, but have normal ageing of their kidneys. Although severe kidney failure will not occur with normal ageing of the kidneys, there is an increased chance of high blood pressure and heart disease or stroke, so that medical checks will be helpful. CAUSES OF CKD You are at risk for kidney disease if you have Diabetes. Diabetes is the leading cause of CKD. High blood glucose, also called blood sugar, from diabetes can damage the blood vessels in your kidneys. Almost 1 in 3 people with diabetes has CKD.1 High blood pressure. High blood pressure is the second leading cause of CKD. Like high blood glucose, high blood pressure also can damage the blood vessels in your kidneys. Almost 1 in 5 adults with high blood pressure has CKD.1 Heart disease. Research shows a link between kidney disease and heart disease. People with heart disease are at higher risk for kidney disease, and people with kidney disease are at higher risk for heart disease. Researchers are working to better understand the relationship between kidney disease and heart disease. Family history of kidney failure. If your mother, father, sister, or brother has kidney failure, you are at risk for CKD. Kidney disease tends to run in families. If you have kidney disease, encourage family members to get tested. Use tips from the family health reunion guide and speak with your family during special gatherings. Your chances of having kidney disease increase with age.The longer you have had diabetes, high blood pressure, or heart disease, the more likely that you will have kidney disease. African Americans, Hispanics, and American Indians tend to have a greater risk for CKD. The greater risk is due mostly to higher rates of diabetes and high blood pressure among these groups. Scientists are studying other possible reasons for this increased risk. Other conditions that affect the kidneys are: Glomerulonephritis, a group of diseases that cause inflammation and damage to the kidney's filtering units. These disorders are the third most common type of kidney disease. Inherited diseases, such as polycystic kidney disease, which causes large cysts to form in the kidneys and damage the surrounding tissue. Malformations that occur as a baby develops in its mother's womb. For example, a narrowing may occur that prevents normal outflow of urine and causes urine to flow back up to the kidney. This causes infections and may damage the kidneys. Lupus and other diseases that affect the body's immune system. Obstructions caused by problems like kidney stones, tumors or an enlarged prostate gland in men. Repeated urinary infections. SYMPTOMS OF CKD Chronic kidney disease (CKD) usually gets worse slowly, and symptoms may not appear until your kidneys are badly damaged. In the late stages of CKD, as you are nearing kidney failure (ESRD), you may notice symptoms that are caused by waste and extra fluid building up in your body. You may notice one or more of the following symptoms if your kidneys are beginning to fail: Itching Muscle cramps Nausea and vomiting Not feeling hungry Swelling in your feet and ankles Too much urine (pee) or not enough urine Trouble catching your breath Trouble sleeping If your kidneys stop working suddenly (acute kidney failure), you may notice one or more of the following symptoms: Abdominal (belly) pain Back pain Diarrhoea Fever Nosebleeds Rash Vomiting Having one or more of any of the symptoms above may be a sign of serious kidney problems. If you notice any of these symptoms, you should contact your doctor right away. COMPLICATIONS OF CKD Your kidneys help your whole body work properly. When you have CKD, you can also have problems with how the rest of your body is working. Some of the common complications of CKD include: Gout Anaemia Bone Disease Heart Disease High Potassium High Calcium Fluid Build-up STAGES OF CKD AND SLOWING MEASURES Chronic kidney disease (CKD) refers to all 5 stages of kidney damage, from very mild damage in Stage 1 to complete kidney failure in Stage 5. The stages of kidney disease are based on how well the kidneys can do their job – to filter waste and extra fluid out of the blood. In the early stages of kidney disease, your kidneys are still able to filter out waste from the blood. In the later stages, your kidneys have to work harder to get rid of waste, and may stop working altogether. The eGFR is a blood test that measures how well the kidneys filter waste from the blood. The stages of kidney disease are based on the eGFR number. Stage 1 CKD Stage 2 CKD Stage 3 CKD Stage 4 CKD Stage 5 CKD Stage 1 CKD Stage 1 kidney disease means kidney damage and an eGFR greater than 90.In Stage 1 kidney disease there is mild kidney damage, and usually no symptoms. If you have Stage 1 kidney disease, it is important to talk to your doctor about how to prevent your kidney damage from getting worse. Most of the time an eGFR greater than 90 means the kidneys are healthy and working well. If you have Stage 1 kidney disease, this means you have other signs of kidney damage even though your eGFR is normal. Signs of kidney damage could be protein in your urine or physical damage to the kidneys.Below are ways to slow kidney damage in Stage 1 kidney disease: Control your blood sugar if you have diabetes. Keep a healthy blood pressure. Eat a healthy diet. Do not smoke or use tobacco. Exercise 30 minutes a day, 5 days a week. Keep a healthy weight. Ask your doctor if there are medicines you can take to protect your kidneys. Make an appointment to see a nephrologist, even if you already have a general doctor. Stage 2 CKD Stage 2 kidney disease means kidney damage and an eGFR between 60 and 89. In Stage 2 kidney disease there is mild kidney damage, and usually no symptoms. If you have Stage 2 kidney disease, it is important to talk to your doctor about how to prevent your kidney damage from getting worse. Most of the time an eGFR between 60 and 89 means the kidneys are healthy and working well. If you have Stage 2 kidney disease, this means you have other signs of kidney damage even though your eGFR is normal. Signs of kidney damage could be protein in your urine or physical damage to the kidneys. Below are ways to slow kidney damage in Stage 2 kidney disease: • Control your blood sugar if you have diabetes. • Keep a healthy blood pressure. • Eat a healthy diet. • Do not smoke or use tobacco. • Exercise 30 minutes a day, 5 days a week. • Keep a healthy weight. • Ask your doctor if there are medicines you can take to protect your kidneys. • Make an appointment to see a nephrologist, even if you already have a general doctor. Stage 3 CKD Stage 3 kidney disease is an eGFR between 30 and 59.Stage 3 kidney disease means the kidneys are moderately damaged and are not working as well as they should. Stage 3 kidney disease is separated into two stages; Stage 3a and Stage 3b. Stage 3a is an eGFR between 45 and 59. Stage 3b is an eGFR between 30 and 44. Many people with Stage 3 kidney disease do not have any symptoms. But if there are symptoms, some of the more common ones are: Swelling in the hands and feet Back pain Urinating more or less than normal By Stage 3 kidney disease, you are more likely to have health complications as a result of waste building up in your body. Common complications from kidney disease are high blood pressure, anaemia, and bone disease. To keep your kidney disease from getting worse, follow the same steps for living a healthy lifestyle as in Stages 1 and 2. There are other things you can do in Stage 3 to keep your kidney disease from getting worse: Visit a nephrologist to make a treatment plan that is right for you. Your nephrologist will tell you how often you will need to have your kidneys checked. Meet with a dietician, who will help you follow a diet that will keep you healthy. If you have diabetes or high blood pressure, ask your doctor about special kinds of blood pressure medicines called ACE inhibitors and ARBs. Sometimes these medicines can help keep kidney disease from getting worse. Stage 4 CKD Stage 4 kidney disease is an eGFR between 15 and 30.Stage 4 kidney disease means your kidneys are moderately or severely damaged and are not working nearly as well as they should. Stage 4 kidney disease should be taken very seriously. It is the last stage of kidney disease before kidney failure. By Stage 4 kidney disease, it becomes more common to have symptoms. Some of the more common symptoms are: Swelling in the hands and feet Back pain Urinating more or less than normal By Stage 4 kidney disease, you will likely have other health complications as a result of waste building up in your body. Common complications from kidney disease are high blood pressure, anaemia, and bone disease. To keep kidney disease from getting worse at this stage, there are steps that must be taken: Have regular appointments with a nephrologist, to make a treatment plan that is best for you. Your nephrologist will tell you how often you will need to have your kidneys checked. Meet with a dietician, who will help you follow a diet that will keep you healthy. If you have diabetes or high blood pressure, ask your doctor about special kinds of blood pressure medicines called ACE inhibitors and ARBs. Sometimes these medicines can help keep kidney disease from getting worse. When you have Stage 4 kidney disease, this is the time to start talking with your nephrologist about how to prepare for kidney failure. Once your kidneys have failed, you will need to start dialysis or have a kidney transplant to live. You can start planning for dialysis or kidney transplant before you reach kidney failure. Preparing for dialysis: There are several things you should consider when getting ready for dialysis. You will need to choose a type of dialysis, your vascular access type, and consider your finances and employment. Preparing for transplant: If you are able to find a living kidney donor, you may not need to start dialysis at all. It is possible to have a transplant when your kidneys are getting close to failure. There are many things to consider as you prepare for transplant. Stage 5 CKD Stage 5 kidney disease is an eGFR less than 15.Stage 5 kidney disease means the kidneys are getting very close to failure or have completely failed. Stage 5 kidney disease has severe symptoms because the kidneys have usually stopped working. If your kidneys fail, toxins and wastes build up in your blood which makes you very sick. Some of the symptoms of kidney failure are: Once live. Itching Muscle cramps Nausea and vomiting Not feeling hungry Swelling in the hands and feet Back pain Urinating more or less than normal Trouble breathing Trouble sleeping your kidneys have failed, you will need to start dialysis or have a kidney transplant to Preparing for dialysis: There are several things you should consider when getting ready for dialysis. You will need to choose a type of dialysis, your vascular access type, and consider your finances and employment. Preparing for transplant: If you are able to find a living kidney donor, you may not need to start dialysis at all. It is possible to have a transplant when your kidneys are getting close to failure. There are many things to consider as you prepare for transplant. DIAGNOSIS OF CKD To check for kidney disease, health care providers use: a blood test that checks how well your kidneys are filtering your blood, called GFR. GFR stands for glomerular filtration rate. a urine test to check for albumin. Albumin is a protein that can pass into the urine when the kidneys are damaged. If you have kidney disease, your health care provider will use the same two tests to help monitor your kidney disease and make sure your treatment plan is working. Blood test for GFR Your health care provider will use a blood test to check your kidney function. The results of the test mean the following: a GFR of 60 or more is in the normal range. Ask your health care provider when your GFR should be checked again. a GFR of less than 60 may mean you have kidney disease. Talk with your health care provider about how to keep your kidney health at this level. a GFR of 15 or less is called kidney failure. Most people below this level need dialysis or a kidney transplant. Talk with your health care provider about your treatment options. A diagram of a GFR dial showing how a GFR that is 60 or higher is normal; a GFR below 60 may mean kidney disease; and a GFR of 15 or lower may mean kidney failure. GFR results show whether your kidneys are filtering at a normal level. You can’t raise your GFR, but you can try to keep it from going lower. Learn more about what you can do to keep your kidneys healthy. Creatinine. Creatinine is a waste product from the normal breakdown of muscles in your body. Your kidneys remove creatinine from your blood. Providers use the amount of creatinine in your blood to estimate your GFR. As kidney disease gets worse, the level of creatinine goes up. Urine Test for Albumin If you are at risk for kidney disease, your provider may check your urine for albumin. Albumin is a protein found in your blood. A healthy kidney doesn’t let albumin pass into the urine. A damaged kidney lets some albumin pass into the urine. The less albumin in your urine, the better. Having albumin in the urine is called albuminuria. A diagram showing a healthy kidney with albumin only found in blood, and a damaged kidney that has albumin in both blood and urine. A healthy kidney doesn’t let albumin pass into the urine. A damaged kidney lets some albumin pass into the urine. A health care provider can check for albumin in your urine in two ways: Dipstick test for albumin. A provider uses a urine sample to look for albumin in your urine. You collect the urine sample in a container in a health care provider’s office or lab. For the test, a provider places a strip of chemically treated paper, called a dipstick, into the urine. The dipstick changes color if albumin is present in the urine. Urine albumin-to-creatinine ratio (UACR). This test measures and compares the amount of albumin with the amount of creatinine in your urine sample. Providers use your UACR to estimate how much albumin would pass into your urine over 24 hours. A urine albumin result of o 30 mg/g or less is normal o more than 30 mg/g may be a sign of kidney disease If you have albumin in your urine, your provider may want you to repeat the urine test one or two more times to confirm the results. Talk with your provider about what your specific numbers mean for you. If you have kidney disease, measuring the albumin in your urine helps your provider know which treatment is best for you. A urine albumin level that stays the same or goes down may mean that treatments are working. Other tests Sometimes other tests are also used to assess the level of damage to your kidneys.These may include: An ultrasound scan, Magnetic resonance imaging (MRI) scan or Computerised tomography (CT) scan – to see what the kidneys look like and check whether there are any blockages A kidney biopsy – a small sample of kidney tissue is removed using a needle so the cells can be examined under a microscope for signs of damage Test results and stages of CKD Your test results can be used to determine how damaged your kidneys are, known as the stage of CKD.This can help your doctor decide the best treatment for you and determine how often you should have tests to monitor your condition. Your eGFR result is given as a stage from 1 to 5: Stage 1 (G1) – a normal eGFR (above 90ml/min), but other tests have detected signs of kidney damage Stage 2 (G2) – a slightly reduced eGFR (60-89ml/min), with other signs of kidney damage Stage 3a (G3a) – an eGFR of 45-59ml/min Stage 3b (G3b) – an eGFR of 30-44ml/min Stage 4 (G4) – an eGFR of 15-29ml/min Stage 5 (G5) – an eGFR below 15ml/min, meaning the kidneys have lost almost all of their function Your ACR result is given as a stage from 1 to 3: A1 – an ACR of less than 3mg/mmol A2 – an ACR of 3-30mg/mmol A3 – an ACR of more than 30mg/mmol For both eGFR and ACR, a higher stage indicates more severe kidney disease. TREATMENT FOR CKD There's no cure for chronic kidney disease (CKD), but treatment can help relieve the symptoms and stop it getting worse. Your treatment will depend on the stage of your CKD. The main treatments are: Lifestyle changes – to ensure you remain as healthy as possible Medication – to control associated problems, such as high blood pressure and high cholesterol Dialysis – treatment to replicate some of the kidney's functions, which may be necessary in advanced (stage 5) CKD Kidney transplant – this may also be necessary in advanced (stage 5) CKD Lifestyle changes The following lifestyle measures are usually recommended for people with kidney disease: stop smoking if you smoke eat a healthy, balanced diet restrict your salt intake to less than 6g (0.2oz) a day do regular exercise – aim to do at least 150 minutes a week moderate your alcohol intake so it's within the recommended limits of no more than 14 alcohol units a week lose weight if you're overweight or obese avoid over-the-counter non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, except when advised to by a medical professional – these medicines can harm your kidneys if you have kidney disease Medication There's no medicine specifically for CKD, but medication can help control many of the problems that cause the condition and complications that can occur as a result of it. You may need to take medication to treat or prevent the different problems caused by CKD. High blood pressure Good control of blood pressure is vital to protect the kidneys. People with kidney disease should usually aim to get their blood pressure down to below 140/90mmHg, but you should aim to get it down to below 130/80mmHg if you also have diabetes. There are many types of blood pressure medication, but medicines called angiotensin converting enzyme (ACE) inhibitors are often used. Examples include ramipril, enalapril and lisinopril. Side effects of ACE inhibitors can include: a persistent dry cough dizziness tiredness or weakness headaches If the side effects of ACE inhibitors are particularly troublesome, you can be given a medication called an angiotensin-II receptor blocker (ARB) instead. High cholesterol People with CKD have a higher risk of cardiovascular disease, including heart attacks and strokes.This is because some of the causes of kidney disease are the same as those for cardiovascular disease, including high blood pressure and high cholesterol.You may be prescribed medication called statins to reduce your risk of developing cardiovascular disease. Examples include atorvastatin, fluvastatin and simvastatin. Side effects of statins can include: headaches feeling sick constipation or diarrhoea muscle and joint pain Water retention You may experience swelling in your ankles, feet and hands if you have kidney disease.This is because your kidneys aren't as effective at removing fluid from your blood, causing it to build up in the body tissues (oedema).You may be advised to reduce your daily salt and fluid intake, including fluids in food like soups and yoghurts, to help relieve the swelling.In some cases you may also be given diuretics (tablets to help you pee more), such as furosemide.Side effects of diuretics can include dehydrationand reduced levels of sodium and potassium in the blood. Anaemia Many people with later-stage kidney disease develop anaemia, which is a lack of red blood cells. Symptoms of anaemia include: tiredness lack of energy shortness of breath a pounding, fluttering or irregular heartbeat (palpitations) If you experience anaemia, you may be given injections of a medication called erythropoietin. This is a hormone that helps your body produce more red blood cells. If you have an iron deficiency as well, iron supplements may also be recommended. Bone problems If your kidneys are severely damaged, you can get a build-up of phosphate in your body because your kidneys cannot get rid of it.Along with calcium, phosphate is important for maintaining healthy bones. But if your phosphate level rises too much, it can upset the balance of calcium in your body and lead to thinning of the bones.You may be advised to limit the amount of high-phosphate food in your diet, such as red meat, dairy products, eggs and fish.If this doesn't lower your phosphate level enough, you may be given medicines called phosphate binders. Commonly used medicines include calcium acetate and calcium carbonate.Some people with kidney disease also have low levels of vitamin D, which is necessary for healthy bones, too.If you're low in vitamin D, you may be given a supplement called colecalciferol or ergocalciferol to boost your vitamin D level. Glomerulonephritis Kidney disease can be caused by inflammation of the filters inside the kidneys, known as glomerulonephritis.In some cases this occurs as a result of the immune system mistakenly attacking the kidneys. If a kidney biopsy finds that this is the cause of your kidney problems, you may be prescribed medicine to reduce the activity of your immune system, such as steroid medication or a medication called cyclophosphamide. Dialysis In a small proportion of people with kidney disease, the condition will eventually get to a point where their kidneys stop working. This rarely happens suddenly, so there should be time to plan the next stage of your treatment. One of the options when CKD reaches this stage is to have dialysis. This is a procedure to remove waste products and excess fluid from the blood. There are 2 main types of dialysis: Haemodialysis – this involves diverting blood into an external machine, where it's filtered before being returned to the body Peritoneal Dialysis – this involves pumping dialysis fluid into the space inside your tummy to draw out waste products from the blood passing through vessels lining the inside of your tummy Haemodialysis is usually done about 3 times a week, either at hospital or at home. Peritoneal dialysis is normally done at home several times a day, or overnight. If you don't have a kidney transplant, treatment with dialysis will usually need to be lifelong. Talk to your doctor about the pros and cons of each type of dialysis and discuss which type you would prefer if your kidney function becomes severely reduced. Kidney transplant An alternative to dialysis for people with severely reduced kidney function is a kidney transplant. This is often the most effective treatment for advanced kidney disease, but it involves major surgery and taking medications to stop your body attacking the donor organ (immunosuppressant) for the rest of your life. You can live with one kidney, which means donor kidneys can come from recently deceased or living donors. But there's still a shortage of donors, and sometimes you could wait months or years for a transplant. You may need to have dialysis while you wait for a transplant. Survival rates for kidney transplants are extremely good nowadays. About 90% of transplants still function after 5 years and many work usefully after 10 years or more. Supportive treatment You'll be offered supportive treatment if you decide not to have dialysis or a transplant for kidney failure, or they're not suitable for you. This is also called palliative or conservative care. The aim is to treat and control the symptoms of kidney failure. It includes medical, psychological and practical care for both the person with kidney failure and their family, including discussion about how you feel and planning for the end of life. Many people choose supportive treatment because they: are unlikely to benefit from or have a good quality of life with treatment don't want to go through the inconvenience of treatment with dialysis are advised against dialysis because they have other serious illnesses, and the negative aspects of treatment outweigh any likely benefits have been on dialysis, but have decided to stop this treatment are being treated with dialysis, but have another serious illness, such as severe heart disease or stroke, that will shorten their life If you choose to have supportive treatment, your kidney unit will still look after you. Supportive care can still allow you to live for some time with a good quality of life. Doctors and nurses will make sure you receive: medicines to protect your remaining kidney function for as long as possible medicines to treat other symptoms of kidney failure, such as feeling out of breath, anaemia, loss of appetite or itchy skin help to plan your home and money affairs bereavement support for your family PROBLEMS IN CLASSIC CKD DIAGNOSIS The different problems in classic diagnosis are: Staging systems for chronic disease should identify risk for progression and complications. The current staging system for CKD, based exclusively on eGFR, does not appear to reliably identify those people at greatest risk for progression. Emerging research suggests an approach that includes multiple factors, such as urine albumin, age, and diabetes status may better predict progression. The current staging requires accuracy of eGFR above 60 mL/min/1.73 m2. However, values above 60 calculated using the MDRD Study equation are not accurate. When using the MDRD Study equation, NKDEP encourages laboratories to report eGFR above 60 as age "≥ 60" rather than as numerical values. While the CKD-EPI equation has increased accuracy for eGFR values above 60 mL/min/1.73 m2 compared to the MDRD Study equation. The influence of imprecision of creatinine assays on the uncertainty of an eGFR value is greater at higher eGFR values. Although kidney function tends to decrease with age, this process has not been well investigated. Many people with age-related kidney function decline may not progress to kidney failure. Thus, the prognosis for a 75-year-old patient with an eGFR of 55 may be different than that for a 45-year-old patient with the same eGFR. GFR may be too narrow a basis on which to assess risk for progression. The approach to staging is likely to evolve as it is informed by ongoing longitudinal research, e.g., the Chronic Renal Insufficiency Cohort Study. The family history is not considered as a major influence in these tests. The diagnosis also depends on the experience of the doctor as the level of uncertainty in CKD is very high. USE OF MACHINE LEARNING IN CKD DIAGNOSIS The different advantages of using machine learning algorithms for ckd diagnosis are: The overall time taken to diagnose ckd can be reduced. The overall time and overall cost for diagnose can be reduced. The imprecision in creatinine assays, complex MDRD and CKD-EPI equations have less effect on diagnosis as their use is reduced. ML algorithms will help in recognising the important features that have major effect on ckd diagnosis. It will also help in eliminating the harmless elements.