Everybody's situation is different - some of these tests may not apply to you. Similarly, your situation may need a test that is not included in this list. Also, having test results that are not in the "normal" range (as provided on your lab sheet) doesn't always mean there is a problem or concern.
Measuring CKD complications: nutrition & malnourishment
Good nutrition is important for providing your body with the resources to fight infections, repair body tissue, and build new muscle. Having a more advanced stage of chronic kidney disease increases your risk of problems with your nutritional health and malnourishment, especially for people who are on dialysis. It is not possible to measure your nutritional health directly, so a variety of tests can be used to check the highest risk areas for health problems.
Albumin is an important protein normally found in the blood that serves many roles in the body. These roles include building muscle, repairing tissue, and fighting infection. A low level of albumin in your blood may be caused by not getting enough protein or calories in your diet, especially if you are on hemodialysis. Since albumin is made in the liver, low albumin levels can also be a sign of liver problems. A low albumin level may lead to health problems such as difficulty fighting off infections. When compared against your other health information and test results, your serum albumin level can help your healthcare professional see if you are getting enough nutrients in your diet.
Normalized protein nitrogen appearance (nPNA)
If you are on dialysis, the nPNA can be a helpful tool that your healthcare professional may use to see if you are eating enough protein. This number is calculated using your blood urea nitrogen (BUN) level just before your dialysis session, your weight, and the amount of protein you ate (including food, drink, and supplements) during a specific period of time. The amount of urea nitrogen in your urine may also be used.
When compared against your other health information and test results, your nPNA results can help your healthcare professional see if you are getting enough protein in your diet.
Another name for this test is the normalized protein catabolic rate (nPCR).
Subjective global assessment (SGA)
If you are on dialysis, your dietitian may use the SGA to help check for signs of nutrition problems. The dietitian will ask you a few questions about your daily diet and any symptoms you may have, measure your weight, and then check your fat and muscle stores in your face, hands, arms, shoulders, and legs. All this information can help your dietitian see if you are getting enough nutrition in your diet. If there are any concerns, your dietitian will work with you to create a plan to help you get the nutrition you need.
Hemoglobin is the protein in your red blood cells that carries oxygen. For adults and children over 15 years living with CKD, anemia is suspected when the hemoglobin level is under 13 g/dL (in males) or under 12 g/dL (in females).
Hematocrit is very similar to hemoglobin. It is a measure of how many red blood cells your body is making. The number is the actual percentage of your blood sample that is made up of red blood cells.
Ferritin (pronounced FAIR-ritt-in) is the stored form of iron found in your body. So, your ferritin level is a measure of how much iron your body has available to use at any given moment. Iron is an important ingredient for making hemoglobin. Having enough iron (ferritin) available is important for being able to make more red blood cells. Having a low level of ferritin means you may need an iron supplement to help treat your anemia.
Transferrin saturation (TSAT)
Transferrin (pronounced trans-FAIR-rin) is a protein that helps move iron throughout your body. So, your transferrin saturation (TSAT, pronounced TEE-sat) number helps show what percent of the transferrin in your blood is currently attached to iron. Your healthcare professional will likely look at your TSAT number in combination with your ferritin level to decide the best way to treat your anemia. In general, a TSAT number of 20% or more is considered “normal”.
Mean corpuscular volume (MCV)
The mean corpuscular volume (MCV) is a blood test that measures the average size of your blood cells. When combined with your other test results and medical history, it can help your healthcare professionals identify the best treatment for your anemia.
For example, an MCV below the reference range suggests the anemia may be caused by low iron. Similarly, an MCV above the reference range suggests the anemia may be caused by low vitamin B12 and/or folic acid.
Parathyroid hormone (PTH)
Parathyroid hormone (PTH), also known as intact parathyroid hormone (iPTH), helps balance the levels of calcium and phosphorus in your blood. When your blood level of calcium goes down, your body makes more PTH to raise it, usually by releasing calcium (and phosphorus) from your bones. PTH also helps remove extra phosphorus from your blood through the kidneys. So, the kidneys play a very active role in this complex process.
Even though this test has the word “thyroid” in the name, it is entirely separate from anything related to your thyroid function. The name “parathyroid” comes from the place where the hormone comes from - very small glands in your neck that sit very close to your thyroid.
A “normal” PTH level in the blood is hard to define because it depends on many other factors (including your stage of CKD, phosphorus level, and calcium level). Ask your healthcare professional what your custom target PTH level should be.
Calcium is an important mineral your body needs for strong bones, and for your nerves, muscles, and heart to work properly. Your kidneys play a very active role in balancing your calcium levels to make sure the level is just right. If your body needs more calcium, your kidneys activate vitamin D to help absorb more calcium from your food and drink. Your body is not able to absorb the calcium without it. In more advanced stages of chronic kidney disease, your kidneys may have a hard time activating vitamin D. This makes it very hard for your body to absorb enough calcium from your food. So, your body starts breaking down bones to supply the calcium. This increases your risk of CKD-related bone disease.
For people living with advanced CKD, your healthcare professional will likely compare your results from this test with your phosphorus and PTH levels. Looking at these three tests together will help them provide you with custom guidance about your target for each item.
Phosphorus (sometimes called phosphate) is an important mineral that your body needs to make strong bones, store energy, and maintain your tissues and cells. Your kidneys play a very active role in keeping your phosphorus levels in the goal range. In more advanced stages of chronic kidney disease, your kidneys may have a hard time removing extra phosphorus from the blood, especially if you are on dialysis. This increases your risk of having phosphorus levels that are too high, and can also lead to CKD-related bone disease.
For people living with advanced CKD, your healthcare professional will likely compare your results from this test with your calcium and PTH levels. Looking at these three tests together will help them provide you with custom guidance about your target for each item.
Vitamin D (25-hydroxyvitamin D; 25(OH)D; calcidiol)
Vitamin D is something your body needs to absorb calcium from your food. Vitamin D is needed for strong teeth and bones. It also helps keep your muscles, nerves, and immune system working well. Your body gets vitamin D from sun exposure and the food that you eat. Once absorbed, your liver converts the vitamin D into its storage form to save for later, also known as 25-hydroxyvitamin D or calcidiol. Your kidneys are responsible for activating the stored vitamin D when your body needs it.
In more advanced stages of chronic kidney disease, your kidneys may have a hard time activating vitamin D. This increases your risk of not absorbing enough calcium from your food. So, your body can start breaking down bones to get the calcium it needs. This increases your risk of CKD-related bone disease. Having a low 25-hydroxyvitamin D (calcidiol) level suggests you may not have enough stored vitamin D ready to use when your body needs it.
Total cholesterol (TC)
Total cholesterol is the total level of cholesterol in your blood. This number includes all the major types of cholesterol that exist in your blood (LDL cholesterol, HDL cholesterol, and triglycerides). For most people, a level below 200 mg/dL is considered the goal. However, there may be situations where a higher TC number is okay – for example, people who have very high HDL (“good”) cholesterol levels. So, your healthcare professional may advise you to focus more attention on the numbers for the different types of cholesterol listed below.
HDL cholesterol (HDL-C)
HDL cholesterol is the level of “good cholesterol” in your blood. It has this name because it helps remove extra fats from your blood. This lowers the risk of having blocked arteries and lowers your risk of heart disease. For this test, a higher number is better, especially if it is 40 mg/dL or higher.
LDL cholesterol (LDL-C)
LDL cholesterol is the level of “bad cholesterol” in your blood. It has this name because it increases the amount of fat that attaches to the walls of your blood vessels. This increases the risk of blockages in your arteries and raises your risk of heart disease. For this test, a lower number is better. A number less than 100 mg/dL is generally considered to be at goal. People who already have heart disease or are at very high risk for developing heart disease may have an even lower LDL-C goal.
Triglycerides (TG or “trigs”)
Triglycerides are a mixture of fats and carbohydrates (sugars) that your body uses as an energy source. A high triglyceride level can increase the risk of heart disease and pancreatitis. For this test, a lower number is better, especially if it is less than 150 mg/dL.
Your hemoglobin A1C, often just called “A1C”, is a blood test that describes your average blood sugar over the past 2-3 months.
- If you have not been diagnosed with diabetes before, this test can be used to check for it. An A1C of 5.7% or more can be a sign that you are at high risk for developing diabetes. An A1C of 6.5% or more can be a sign that you have diabetes. A repeat test is usually recommended to confirm the results are accurate before a diagnosis can be made.
- If you have been diagnosed with diabetes before, this test is used to see how well you are managing it. The goal for most adults living with diabetes is an A1C of 7% or lower. Some people may need a higher or lower goal depending on their clinical situation. Ask your healthcare professional what your goal A1C level should be.
The A1C test may not be as accurate for people on dialysis or receiving erythropoietin stimulating agents (ESAs, a medication for anemia caused by CKD).
Serum (blood) glucose (sugar)
Glucose (sugar) is an important source of energy for your body, including your brain and red blood cells. This test describes the amount of glucose that is in your blood at the time of testing.
- If you have not been diagnosed with diabetes before, this test can be used to check for it (although an A1C test is usually more preferred).
- A fasting blood glucose level of 100 mg/dL or higher is a sign that you may be at high risk for developing diabetes.
- A fasting level of 126 mg/dL or more is a sign that you may have diabetes.
- In both cases, “fasting” means you have not had anything to eat or drink (except water) during the 8-12 hours before the test.
- A blood sugar level of 200 mg/dL or more at any time is also a sign that you may have diabetes.
- In all of these cases, a repeat test is usually recommended to confirm the results are accurate before a diagnosis can be made.
- If you have been diagnosed with diabetes before, this test is used to see how well you are managing it. Keeping your blood glucose (sugar) level within your goal range is important. A blood sugar level that is too low (less than 70 mg/dL) can starve your brain and other parts of the body of energy. A blood sugar level that is too high can cause damage to your kidneys, heart, and other organs in your body. Everyone’s goal range is different – ask your healthcare professional what your goal range is.