Cystatin C test with EGFR
The cystatin C test (which also includes estimated creatinine clearance eGFR) can be done along with creatinine or creatinine clearance test in cases where those tests aren’t appropriate, such as patients taking creatine supplements for bodybuilding. These supplements can increase creatinine and decrease creatinine clearance, which can alarm doctors who fear kidney dysfunction. This creatinine increase is not clinically relevant but running a Cystatin C test can give physicians reassurance and allow the patient to keep taking that effective bodybuilding supplement.
The Cystatin C test and the creatinine test are both used to evaluate kidney function, but they provide different information about the kidneys and are used for different purposes. The Cystatin C test provides a more sensitive measure of kidney function and is not affected by muscle mass or other factors that can affect creatinine levels, making it a useful alternative to the creatinine test for monitoring kidney function in certain populations.
Table of Contents
What is Cystatin C Test?
Cystatin C is a protein found in almost all the cells in the body. Cystatin C helps to regulate the activity of enzymes needed to break down bigger molecules both inside of and around those cells.
Cystatin C level in the blood can be measured to determine how well the kidneys are functioning. The kidneys, liver, and spleen all work to filter the blood and excrete any waste substances as urine. This filtration process happens in a microscopic structure in the kidneys; the glomerulus. Each kidney contains approximately one-million glomeruli that function as tiny sieves to extract waste. The glomerular filtration rate (GFR) rate is a measure of how well the glomeruli are filtering blood.
How Does the Cystatin C Test Compare with the Creatinine Test?
Both the Cystatin C test and the creatinine test are used to evaluate kidney function, but they provide different information about the kidneys and are used for different purposes. The creatinine test provides a general measure of kidney function and is often used as part of a routine health check. The Cystatin C test provides a more sensitive measure of kidney function, particularly in the early stages of kidney disease, and is often used to monitor the progression of kidney disease.
One advantage of the Cystatin C test over the creatinine test is that it is not affected by muscle mass. Creatinine levels can be elevated in individuals with high muscle mass, leading to an overestimation of kidney function. Cystatin C levels are not affected by muscle mass, making the test a more accurate measure of kidney function in individuals with high muscle mass.
Another advantage of the Cystatin C test is that it is not affected by age, sex, or other factors that can affect creatinine levels. This makes the Cystatin C test a useful alternative to the creatinine test for monitoring kidney function in individuals who may be at risk for kidney disease.
Who May Need a Cystatin C Test?
The cystatin C test (which also includes estimated creatinine clearance eGFR) can be done along with creatinine or creatinine clearance test in cases where those tests aren’t appropriate, such as:
- Patients taking creatine supplements for bodybuilding. These supplements can increase creatinine and decrease creatinine clearance, which can alarm doctors who fear kidney dysfunction. This creatinine increase is not clinically relevant but running a Cystatin C test can give physicians reassurance and allow the patient to keep taking that effective bodybuilding supplement.
- In patients with cirrhosis
- Cases of morbid obesity
- Malnourishment
- Reduced muscle mass
Since the concentration of cystatin C in the blood will not change due to infection or inflammation and isn’t affected by body weight, drugs or diet - cystatin C level could be a more reliable indicator of kidney health than creatinine.
Testing for cystatin may also be useful to detect kidney disease early when the affected person isn’t experiencing many (if any) symptoms, and other test like creatinine and eGFR results are normal.
For more information, please read
Is the Cystatin C Test Better than Creatinine for Muscular Men?
HOW DOES DISCOUNTEDLABS.COM WORK?
-
Go to the "Find a Location" page to find the closest lab location. No need to make an appointment since walk-ins are welcomed. Once you have identified your closest location, go to step 2.
-
Go to "Choose a Test" and add your selection (s) in the shopping cart. If you prefer to save money on bundled tests, we have created "Lab Test Panels" that can help you decide what to order.
-
If you have a discount coupon code, add it to your cart.
-
A $8 lab processing fee will be added to your total.
-
Pay using a credit card.
-
You will receive an order confirmation and instructions email on how to download your lab request.
-
Print lab request form that you downloaded.
-
Take that form to the closest location. Get your blood drawn.
-
You will receive an email when the results are ready for you to download.
Note: You cannot place an order under someone else's profile. The profile person's name will appear on the lab order form.If you have further questions, please email [email protected].