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Although the CMP is used in the diagnosis and management of many diseases, it is most often used to monitor patients with Type 2 diabetes, kidney disease, and chronic liver diseases. According to the Centers for Disease Control and Prevention (CDC), as many as 28,500,000 people in the United States have Type 2 diabetes. The National Kidney Foundation estimates that 37 million Americans have kidney disease. Approximately 4.5 million adults, or 1.8% of the adult population of the United States, have been diagnosed with chronic liver disease.
This guide provides a detailed overview of the comprehensive metabolic panel, including why it’s ordered and how the test is performed. It also contains information on the symptoms and consequences of Type 2 diabetes, kidney disease, and chronic liver diseases.
The purpose of the comprehensive metabolic panel is to screen for high or low blood sugar, determine how well the liver and kidneys are functioning, and check for electrolyte imbalances. Electrolytes are electrically charged substances that help the human body carry out important functions such as contracting the muscles and generating energy in the cells. The CMP can also be used to screen for metabolic disorders, assess an individual’s acid-base balance, and determine if an individual has a normal amount of protein in the blood.
The comprehensive metabolic panel should be performed as part of a routine physical, according to MedlinePlus. It may also be ordered when an individual has signs or symptoms of any of the following:
CMP testing is performed on a blood sample drawn from a vein. The sample is collected by a phlebotomist and analyzed in a clinical laboratory.
In some cases, an individual must refrain from eating or drinking for 10 to 12 hours before the test. Otherwise, no special preparation is required.
Although there are several types of diabetes, Type 2 is by far the most common. Type 2 diabetes develops when an individual does not produce insulin or is unable to use insulin effectively. Insulin is a hormone that helps glucose (blood sugar) enter the cells. Due to a lack of insulin, people with uncontrolled diabetes have elevated glucose levels. Some of the most common symptoms of Type 2 diabetes include excessive thirst, frequent urination, fatigue, unexplained weight loss, blurred vision, slow-healing wounds, and frequent hunger.
Some individuals are more likely to develop Type 2 diabetes than others. People with high blood pressure, depression, a history of stroke or heart disease, a family history of diabetes, high levels of triglycerides, low levels of “good” cholesterol (HDL cholesterol), or a history of gestational diabetes have an elevated risk of developing Type 2 diabetes. Obesity and lack of physical activity are also risk factors for this disease.
The kidneys are responsible for filtering wastes from the blood and making urine. In people with kidney disease, the kidneys don’t carry out their filtering duties as well as they should. Diabetes, high blood pressure, and chronic kidney infections are some of the conditions that increase the risk for kidney disease. The disease can also develop when someone uses illegal drugs or takes large quantities of over-the-counter pain medications like ibuprofen and acetaminophen.
In some cases, kidney disease causes no symptoms until it’s fairly advanced, which is why the comprehensive metabolic panel is so important. The CMP can reveal a decline in kidney function even before the signs and symptoms of the disease are evident. Fatigue, itchy skin, difficulty sleeping, an increased urge to urinate, bloody or foamy urine, muscle cramps, and swelling of the feet and ankles are among the most common signs and symptoms of kidney disease.
Chronic liver diseases develop when the liver tissue is destroyed over time. Cirrhosis and fibrosis are two of the most common chronic liver diseases. Cirrhosis destroys the liver tissue, causing scar tissue to form in its place. As the scar tissue grows, it blocks normal blood flow, inhibiting the liver’s ability to metabolize medications, use hormones, and break down nutrients. Cirrhosis also prevents the liver from producing proteins and other substances the body needs to function normally. Fibrosis develops when an individual has a liver infection, inflammation of the liver, or some type of liver injury. Like cirrhosis, fibrosis causes scar tissue to form in the liver, preventing it from functioning normally.
Fibrosis, on its own, does not cause any symptoms. Cirrhosis causes a variety of signs and symptoms, including the following:
A comprehensive metabolic panel has 14 components:
Glucose, also known as blood sugar, is a major source of energy for the human body. Checking glucose levels helps in the diagnosis and management of diabetes, hypoglycemia, and other conditions that can affect the amount of glucose in the bloodstream. Sodium, carbon dioxide, chloride, and potassium are electrolytes involved in controlling the body’s acid-base balance and maintaining normal fluid levels. Checking electrolyte levels is helpful for diagnosing dehydration, kidney disease, and other conditions that can cause electrolyte imbalances.
Creatinine and blood urea nitrogen (BUN) are waste products filtered out of the blood by the kidneys. An elevated creatinine or BUN level can indicate that the kidneys are not functioning normally. Calcium is a mineral that is essential for the normal function of the heart, muscles, and nervous system. The CMP helps determine if an individual’s calcium level is too high or too low. ALP, AST, and ALT are enzymes manufactured by the liver, albumin is a protein made by the liver, and bilirubin is a waste product made by the liver. These components of the CMP are useful for assessing an individual’s liver function. Total protein is just what it sounds like — the total amount of protein in the blood. Checking total protein levels is helpful in the diagnosis and management of nutritional deficiencies, liver diseases, and kidney diseases.
The CMP requires a blood sample drawn from an individual’s vein. This sample is usually collected by a phlebotomist, a person who has been trained to collect laboratory specimens and handle them safely. The collection process is fairly simple; the phlebotomist ties a tourniquet around the upper arm, cleans the skin with an antiseptic wipe, and inserts a needle into the vein. The blood is collected in a test tube, which is labeled with the patient’s name and other identifying information.
Treatment options for Type 2 diabetes include lifestyle changes and medications. For individuals who are overweight or obese, lifestyle changes are usually aimed at losing excess weight and keeping it off. Weight loss helps with glucose control, which can prevent diabetes complications in the future. Type 2 diabetics must also make healthy food choices, even if they don’t need to lose weight. An individual’s nutritional needs vary based on many factors, so it’s important for a Type 2 diabetic to work with a registered dietitian or other medical professional to develop a customized nutrition plan.
It’s also important for people with Type 2 diabetes to get regular aerobic exercise. The American Academy of Family Physicians recommends 150 minutes per week of moderate exercise, but anyone with diabetes should consult with a medical professional before developing an exercise plan. Depending on factors such as weight and medical history, some individuals may need more or less than 150 minutes of exercise per week.
If lifestyle changes are not enough to control glucose levels, a Type 2 diabetic may have to take daily medication. Metformin is an oral medication that reduces the amount of glucose made in the liver and makes the body more sensitive to insulin. This helps more glucose enter the cells, reducing the amount of glucose remaining in the bloodstream. Some diabetics have to take insulin to prevent their glucose levels from getting too high. Insulin is available in rapid-acting, short-acting, intermediate-acting, and long-acting forms.
In most cases, people with chronic kidney disease do not regain their lost kidney function. Therefore, treatment for kidney disease aims to preserve the remaining kidney function and prevent complications. Like diabetics, people with kidney disease are often advised to make lifestyle changes to keep their health under control. When the kidneys are damaged, they don’t filter as well as they should, which allows fluid and waste products to build up in the blood. Reducing sodium intake and avoiding alcoholic beverages can help prevent swelling and other complications. For people with advanced kidney disease, it may be necessary to reduce protein intake or limit the amount of liquid consumed each day. Getting regular exercise and avoiding tobacco products can also help people with kidney disease preserve their health.
Some people with kidney disease need hemodialysis, a mechanical process that filters excess fluid and waste products out of the blood. The device used for hemodialysis, which is called a dialyzer, replaces some of the functions of the damaged kidneys. During hemodialysis, blood is removed from the patient’s body and filtered by the dialyzer. Once the blood has been filtered, it is returned to the patient’s bloodstream. Hemodialysis can help an individual with kidney disease feel better, but it does not cure kidney disease. If kidney disease progresses to end-stage renal failure, the individual may need a kidney transplant. A transplant is a surgical procedure in which a healthy donor kidney is placed in the body to do the work of the recipient’s failing kidneys.
Cirrhosis has several causes, so there is no single treatment plan that works for every person with the disease. For someone with alcoholic cirrhosis, the individual may be advised to stop consuming alcohol and seek treatment for alcoholism. Weight loss can help people with nonalcoholic fatty liver disease prevent further liver scarring and control their symptoms, as losing weight can reduce the amount of fat in the liver. People with chronic hepatitis may take medications to fight the hepatitis virus and prevent additional liver damage. For people who develop cirrhosis as a complication of an autoimmune disorder, it may be necessary to take medications to suppress immune activity and prevent the immune system from attacking healthy liver tissue. If an individual with chronic liver disease develops liver failure, a liver transplant is the only available treatment option.
The results of a comprehensive metabolic panel are usually ready within three days; however, it may take up to a week to receive the results from the ordering health care provider. Some providers call their patients with the results, while others send results letters via the postal service. If the ordering provider sends a letter, it may take several days to receive it.
In healthy people, the comprehensive metabolic panel is usually ordered once per year as part of a routine physical; however, some people need the test more often. Individuals with liver and kidney disease need to have a CMP every three to six months. A patient awaiting a kidney transplant may need to have a CMP and other blood tests every month in preparation for transplant surgery. Diabetics may need to have the test more often to ensure that high glucose levels have not damaged the kidneys or caused other complications.
The basic metabolic panel has fewer components than the comprehensive metabolic panel. It includes glucose, sodium, potassium, calcium, BUN, creatinine, chloride, and carbon dioxide; it does not include the liver enzymes, albumin, bilirubin, and total protein found in the CMP.
Yes. Insulin, hormones, and steroids can all affect the results of a CMP. An individual who takes any of these medications should alert the ordering provider before having blood drawn.
Having blood drawn is a relatively low-risk procedure, but there is some risk of infection if the venipuncture site is not cleansed properly. Bruising and fainting can also occur after a blood draw.
To learn more about Type 2 diabetes, kidney disease, and liver diseases, visit the following resources.
|Centers for Disease Control and Prevention||www.cdc.gov/diabetes/basics/type2.html||The CDC offers a comprehensive overview of Type 2 diabetes, including causes, symptoms, and options for managing the condition.|
|National Institute of Diabetes and Digestive and Kidney Diseases||www.niddk.nih.gov/health-information/diabetes||Patients with diabetes can learn more about making healthy food choices and getting enough exercise with this NIDDK resource.|
|National Kidney||www.kidney.org/atoz/content/about-chronic-kidney-disease||The National Kidney Foundation defines chronic kidney disease and explains its causes and symptoms.|
|National Institute of Diabetes and Digestive and Kidney Diseases||www.niddk.nih.gov/health-information/liver-disease/cirrhosis||The NIDDK offers several fact sheets on the definition, symptoms, causes, and treatment options for cirrhosis of the liver.|
|MedlinePlus||www.medlineplus.gov/liverdiseases||MedlinePlus provides an overview of chronic liver diseases and links to more information on relevant diagnostic tests and treatment options.|