The answers are in your blood

Yes, you need to face the needle: Regular tests are best

By Amy Leap Pocono Record Writer

January 26, 2012

The body is an intricate machine, and normally all the organs and functions work together to keep you healthy. But doctors need to check now and then to ensure everything is working as it should — and an external exam won't suffice.

"Blood tests are one of the best ways for a physician to gain information about your health," said Anna Friemann of Hamilton Township. She is a nurse in the Level II Neuro Trauma Center at Community Medical Center, Scranton.

The Centers for Disease Control and Prevention advises having routine blood tests done somewhere around 35 and 40 years old. This gives the doctor a starting point to monitor any changes as you get older.

"At around the age of 50, there are specific blood tests the doctor should order on a yearly basis, and if you haven't had the tests, you should ask the physician about having them," she said.

When the doctor orders the lab to run a complete series of tests, you can find out about the status of the liver, the thyroid, the blood cholesterol as well as the blood sugar, Friemann said.

Women and men 50 and older

The following blood chemistry tests require a single sample of blood serum, which may require several vials of blood that can be used to run a series of tests quickly and inexpensively.

The following are the most commonly requested tests:

r Complete Blood Count is the most common test and is usually ordered as part of a complete physical examination. CBC measures the number, size and shape of the types of cells in the blood.

r Glucose test can indicate diabetes if the level is high, or hypoglycemia if it is low. A fasting glucose of less than 100 is normal, a level of 100 to 125 is abnormal and called "impaired glucose tolerance" and a level of 126 or greater means diabetes.

r Blood Urea Nitrogen and creatinine tests see if the kidneys are working normally and measures the amount of nitrogen in blood that comes from the waste product urea. Urea is made when protein is broken down in the body. Urea is made in the liver and passed out of the body in the urine. If the kidneys are not able to remove urea from the blood normally, the BUN level rises.

The level of creatinine in the blood also tells how well the kidneys are working. A high creatinine level may mean the kidneys are not working properly. BUN and creatinine tests can be used together to find the BUN-to-creatinine ratio that tells if the kidneys are working properly.

r Sodium, potassium and chloride tests are especially important when taking diuretics, known as water pills. The tests measure the blood salts or electrolytes.

r Uric Acid test measures the level of acid, a waste product of all cells. An elevated level could mean kidney disease or gout.

r Albumin test measures the blood protein the liver produces. A low albumin count can be a sign of liver or kidney disease.

r Globulin test measures the level of blood protein produced by the immune system. A high level can point to chronic inflammation, infection or blood disorders, such as multiple myeloma.

r Calcium test has nothing to do with how much calcium is in the bones. It is a component of the blood that helps all the cells in the body function normally. A high count can point to a disorder called hyperparathyroidism, which predisposes people to kidney stones and low bone density.

r Serum Glutamine Pyruvic Transaminase test measures an enzyme normally present in liver and heart cells. SGPT is released into the blood when the liver or heart is damaged. Elevated levels of SGPT can happen as a result of a heart attack or from viral hepatitis.

r Lactate Dehydrogenase test measures an enzyme produced by many cells of the body. If LDH is extremely high, it can indicate a malignancy, and the doctor will do additional tests to rule this out.

r Bilirubin test measures a chemical in bile that gives it the yellow color. If the bile passages from the liver to the intestine are blocked, the bilirubin level will be high. Possible causes include gallstones and liver disease.

r Gamma Glutamyl Transpeptidase test measures the amount of enzyme produced by the liver. Obesity and excessive alcohol use are the most common reasons it can be mildly increased. It will also be elevated when there is blockage of bile and with liver disease.

r Blood fats or blood lipids test identifies lipids, often listed together in a separate "panel" on the blood chemistry report as Low Density Lipoprotein and High Density Lipoprotein. The total cholesterol is the sum of the LDL and HDL. High total cholesterol levels are linked to heart disease. The lower the total cholesterol the better. A total below 200 is desirable.

HDL is the good cholesterol. The more of it, the better. Ideally, the HDL cholesterol should be at least 30 percent of the total amount. In men, an HDL greater than 40 is normal; in women, an HDL greater than 50 is normal.

LDL is the bad cholesterol. A high LDL puts the patient at risk for heart disease, and the doctor will suggest diet and often medication to get the LDL cholesterol below 130. If diabetes or heart disease is present, the treatment goal for LDL cholesterol should be below 100.

Triglycerides are the other form of fat in the blood. The level will be much higher after a meal. If the level is out of range, it should be repeated after an overnight fast. Elevated levels increase the risk of heart disease and could be a sign of early diabetes. Ideally, they should be under 150.

r Thyroid function test can diagnose an underactive thyroid, a common condition in women over age 50. It also measures the level of two hormones produced by the thyroid glands: thyroxine 3 (T3) and thyroxine 4 (T4). Both regulate the metabolism.

The brain keeps levels normal by sending thyroid stimulating hormone (TSH) to the thyroid gland if the T3 and T4 are low. The TSH level is the best indicator of the condition of the thyroid and the effects of thyroid medication.

For example, if the thyroid hormone levels (T3 and T4) are low, the TSH level will be high. If the thyroid hormone levels are too high, then the TSH level will be low or immeasurable.

Just for women

r C-reactive protein test measures blood inflammation and marker of future heart disease risk. The test is recommended for women with a waist circumference over 35 inches because of increased risk for metabolic syndrome and heart disease.

Just for men

r Prostate-Specific Antigen test measures the prostate-specific protein produced by cells of the prostate gland. A high PSA can mean prostate cancer or prostate inflammation.

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Know Your ALT

The Serum Alt: Frequently Asked Questions

What is it?
The ALT is a protein manufactured in the liver which participates in metabolism. The term ALT refers to alanine-amino transferase. This protein is an enzyme which participates in modifying amino acids, the building blocks of proteins. The ALT is made predominately in the liver and therefore alterations in the serum ALT can be directly related to disturbances of liver structure and function.

Is the serum ALT hard to measure?
It is straightforward to have ones blood sample tested for a serum ALT, it only requires obtaining a blood sample. The serum ALT is easily measured in laboratories throughout the world. The methodology may vary from laboratory to laboratory, making direct comparisons of the absolute serum ALT value difficult, but all laboratories have a normal range for men and women.

What does an elevated serum ALT reflect?
The ALT is manufactured within liver cells. Elevations in the serum ALT reflect alterations in the structure and function of the liver. Damaged liver cells release ALT into the blood stream where it can then be measured. The serum ALT, therefore, reflects damage to liver cells, liver injury, and underlying liver disease.

Why should I know my serum ALT?
We should all be aware of our health. Unfortunately, unlike diseases affecting other organs, injury to the liver can be silent. Patients may not have any symptoms and the ALT can be elevated for years before one is aware of an underlying liver disease. When one develops symptoms from liver disease, it usually reflects advanced damage to the liver. Once significant damage to the liver has occurred, therapies other than liver transplantation, may not be very beneficial. Therefore, making the diagnosis of a liver disease early in its course can be very beneficial in regards to receiving specific therapies and modifying lifestyle.

My doctor also measures other blood tests. What are they and is the serum ALT the best test?
The liver is a complex organ with a variety of essential functions for the body. It participates in metabolism, produces bile, and generates proteins secreted into the blood, so your doctor may measure compounds associated with all of these liver functions. All of those tests are frequently measured in a battery of tests referred to as a “liver panel.” Depending upon the type and nature of the underlying liver injury and therefore the liver disease, changes in the magnitude of the various components of this panel provide meaningful information to your physician. However, if one simply wants to know whether one has liver wellness or may have an underlying liver disease, the ALT is likely the most sensitive test for the vast majority of liver illness.

Is there a direct correlation between the magnitude of the serum ALT elevation and the severity of the underlying liver disease?
Although there can be a relationship between the magnitude of elevation in the serum ALT and the severity of the abnormalities in liver structure and function, this relationship is not absolute. Patients with advanced scarring of the liver may have significant liver dysfunction despite only mild elevations of the serum ALT. Therefore, any elevation of the serum ALT should be taken seriously and one should seek appropriate medical care to determine the cause.

What are some common causes of an elevated serum ALT?
Perhaps the most common cause in the North American population is fat accumulation within liver cells. Fat can accumulate anywhere in the body, but its accumulation in the liver cells is toxic to the liver. In particular, patients who are above their ideal body weight, have diabetes, or elevations in their blood lipids, may be at risk for having fat within the liver. The serum ALT is a common approach to determine whether one may have fat in the liver and if it is injurious to this organ. Other common causes of an elevated serum ALT include excessive consumption of alcohol, infection by chronic hepatitis viruses such as hepatitis B and C, toxicity from pharmaceutical medications, a genetic liver disease associated with an excess accumulation of iron in the liver, and autoimmune liver diseases. The latter are a variety of liver diseases in which the body’s immune system inflicts damage on ones own organ.

I have an elevated ALT. What should I do?
If you have an elevated ALT, you should seek medical attention. The vast majority of primary care physicians and specialists in gastroenterology and hepatology, can perform the necessary testing to determine the cause of an elevated serum ALT.

How often should I have my serum ALT measured?
Like the serum cholesterol and blood glucose tests for elevated cholesterol and diabetes, respectively; one should have the serum ALT measured repeatedly and regularly over time. A conservative approach would be to have ones serum ALT measured on an annual basis during the annual physical examination.

Source

The healthy range for serum ALT and the clinical significance of “unhealthy” normal ALT levels in the Korean population

Hyun Seok Kang 1, Soon Ho Um 1, Yeon Seok Seo 1,*, Hyonggin An 2, Kwang Gyun Lee 1, Jong Jin Hyun1, Eun Sun Kim 1, Sung Chul Park 1, Bora Keum 1, Ji Hoon Kim 1, Hyung Joon Yim 1, Yoon Tae Jeen1, Hong Sik Lee 1, Hoon Jai Chun 1, Chang Duck Kim 1, Ho Sang Ryu 1

Journal of Gastroenterology and Hepatology
Accepted Article (Accepted, unedited articles published online for future issues)
DOI: 10.1111/j.1440-1746.2010.06481.x
Journal compilation © 2010 Journal of Gastroenterology and Hepatology Foundation

Author Information

1 Departments of Internal Medicine and
2 Biostatistics, Korea University College of Medicine, Seoul, Korea

* Correspondence: Yeon Seok Seo,

* Correspondence: Yeon Seok Seo, MD, PhD Division of Gastroenterology and Hepatology, Department of Internal Medicine, Korea University Anam Hospital, Korea University College of Medicine, Anam-dong 5-ga, Seongbuk-gu, Seoul 136-705, Korea Tel: 82-2-920-6608, Fax: 82-2-953-1943, E-mail: drseo@korea.ac.kr

Publication History
Accepted manuscript online: 17 AUG 2010 12:20PM EST
Accepted date: 02 August 2010

Keywords:
aminotransferase;metabolic syndrome;insulin resistance;nonalcoholic fatty liver disease

ABSTRACT

Background and Aims: It remains unclear whether the currently used normal range for serum alanine aminotransferase (ALT) levels really reflects a healthy liver. This study was performed to evaluate the healthy range of serum ALT in the Korean adult population and to determine the clinical significance of unhealthy levels.

Methods: We reviewed the medical records, including questionnaires and the results of laboratory and radiologic tests conducted at the Health Promotion Center in Korea University Anam Hospital between March 2005 and February 2007. The records written in questionnaire form included the baseline data, including physical status, social behaviors, medication history, and past and present disease histories.

Results: The mean age of the 7403 enrolled subjects was 48 years, and 49.9% of them were men. A healthy cohort was selected after excluding subjects who showed any abnormalities of the factors that were significantly associated with serum ALT level on multivariate regression analysis. The upper limit of the healthy range of serum ALT level (i.e., 95th percentile) in the healthy population was 31 IU/L for the men and 23 IU/L for the women. The prevalence of metabolic syndrome and insulin resistance were significantly higher in subjects with an “unhealthy” normal ALT level than in subjects with a healthy ALT level.

Conclusion: In our study, the upper limit of the healthy range of serum ALT level was 31 IU/L for the men and 23 IU/L for the women. An unhealthy normal ALT level was associated with higher prevalence of metabolic syndrome and insulin resistance.

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Liver Enzymes: A Look at AST and ALT

From Charles Daniel, former About.com Guide
Updated September 05, 2008

About.com Health's Disease and Condition content is reviewed by the Medical Review Board

Liver enzymes allow doctors to learn about the health of your liver. There are thousands of these enzymes in the liver and blood stream, but two of them -- known as aminotransferases AST and ALT -- are especially useful for determining liver disease.

What Are Aminotransferases?

Aminotransferases are chemicals the liver uses to help make the energy-storage molecule glycogen. Aspartate aminotransferase, or AST, is found in the liver, but also the brain, pancreas, heart, skeletal muscle, kidneys and lungs. Alanine aminotransferase, or ALT, is primarily found in the liver. To remember the difference between the two, I use the "L" in ALT to remind me of the liver.

Why Are AST and ALT Useful?

Because these enzymes are found in liver cells (hepatocytes) which have lots of contact with your blood supply, AST and ALT can "leak" into the blood if the hepatocytes are damaged. Blood tests can determine the level of these enzymes in your blood and doctors can use this information to form a diagnosis. Abnormally high levels of both liver enzymes show that liver cells have been damaged, but they can't tell what caused the damage. Because AST is located in many places in the body, high levels of AST alone don't suggest liver disease (a notable, but rare, exception is Wilson's disease). However, the ratio of AST to ALT, or the level of AST compared to the level of ALT, provides many clues to what's going on inside. Based on these ratios, doctors can focus their attention on a particular kind of liver disease. Here are some common guidelines used for liver disease:

• An AST:ALT ratio equal to one (the level of ALT is higher or equal to AST), but the levels are very high, suggests acute viral hepatitis or drug-related hepatitis.
• An AST:ALT ratio higher than 2:1 (two times the level of AST to ALT) is very suggestive of alcoholic liver disease.
• An AST:ALT ratio higher than one (where the level of AST is higher than the ALT) could also indicate cirrhosis in a person that doesn't have alcoholic hepatitis.

Because increased enzyme levels can be seen in other diseases (heart attack, obesity, diabetes mellitus, mononucleosis), they are just one piece of a larger puzzle. To give doctors a complete clinical picture, enzyme levels must be used with other blood tests, patient examination and medical history.

• Diagnosing Hepatitis
• Blood Tests for Hepatitis C 

What Are the Normal AST and ALT Levels?

The normal levels of AST and ALT vary from person to person and depend on your BMI, or the ratio of your height and weight. A small amount of AST and ALT is normally in your blood, so it's really a large increase over your normal level that indicates a problem. For people with acute viral hepatitis, they might have aminotransferase levels higher than 1,000 IU/L. This stands for International Units per Liter (of blood) and is a unit of measurement that labs use for many medical tests. Common ranges for AST and ALT are:

• AST 2-45 IU/L
• ALT 2-40 IU/L

How Are Liver Enzymes Tested?

To test for AST and ALT, a doctor needs to order an enzyme test, which usually consists of several additional tests like albumin, bilirubin and prothrombin time. A technician will draw a sample of your blood and send it to a lab to be tested. The results are sent to your doctor.

Sources:
Pratt DS, Kaplan MM. Evaluation of Liver Function. In: AS Fauci, E Braunwald, DL Kasper, SL Hauser, DL Longo, JL Jameson, J Loscaizo (eds), Harrison’s Principles of Internal Medicine, 17e. New York, McGraw-Hill, 2008.

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Blood Basics

 The Components of Blood and Their Importance

Blood Basics

Blood is a specialized body fluid. It has four main components: plasma, red blood cells, white blood cells, and platelets. Blood has many different functions, including:

• transporting oxygen and nutrients to the lungs and tissues
• forming blood clots to prevent excess blood loss
• carrying cells and antibodies that fight infection
• bringing waste products to the kidneys and liver, which filter and clean the blood
• regulating body temperature

The blood that runs through the veins, arteries, and capillaries is known as whole blood, a mixture of about 55 percent plasma and 45 percent blood cells. About 7 to 8 percent of your total body weight is blood. An average-sized man has about 12 pints of blood in his body, and an average-sized woman has about 9 pints.

The Components of Blood and Their Importance

Many people have undergone blood tests or donated blood, but hematology – the study of blood – encompasses much more than this. Doctors who specialize in hematology (hematologists) are leading the many advances being made in the treatment and prevention of blood diseases. If you or someone you care about is diagnosed with a blood disorder, your primary care physician may refer you to a hematologist for further testing and treatment.

Plasma

The liquid component of blood is called plasma, a mixture of water, sugar, fat, protein, and salts. The main job of the plasma is to transport blood cells throughout your body along with nutrients, waste products, antibodies, clotting proteins, chemical messengers such as hormones, and proteins that help maintain the body's fluid balance.

Red Blood Cells (also called erythrocytes or RBCs)

Known for their bright red color, red cells are the most abundant cell in the blood, accounting for about 40-45 percent of its volume. The shape of a red blood cell is a biconcave disk with a flattened center – in other words, both faces of the disc have shallow bowl-like indentations (a red blood cell looks like a donut).

Production of red blood cells is controlled by erythropoietin, a hormone produced primarily by the kidneys. Red blood cells start as immature cells in the bone marrow and after approximately seven days of maturation are released into the bloodstream. Unlike many other cells, red blood cells have no nucleus and can easily change shape, helping them fit through the various blood vessels in your body. However, while the lack of a nucleus makes a red blood cell more flexible, it also limits the life of the cell as it travels through the smallest blood vessels, damaging the cell’s membranes and depleting its energy supplies. The red blood cell survives on average only 120 days.

Red cells contain a special protein called hemoglobin, which helps carry oxygen from the lungs to the rest of the body and then returns carbon dioxide from the body to the lungs so it can be exhaled. Blood appears red because of the large number of red blood cells, which get their color from the hemoglobin. The percentage of whole blood volume that is made up of red blood cells is called the hematocrit and is a common measure of red blood cell levels.

White Blood Cells (also called leukocytes)

White blood cells protect the body from infection. They are much fewer in number than red blood cells, accounting for about 1 percent of your blood.

The most common type of white blood cell is the neutrophil, which is the “immediate response” cell and accounts for 55 to 70 percent of the total white blood cell count. Each neutrophil lives less than a day, so your bone marrow must constantly make new neutrophils to maintain protection against infection. Transfusion of neutrophils is generally not effective since they do not remain in the body for very long.

The other major type of white blood cell is a lymphocyte. There are two main populations of these cells. T lymphocytes help regulate the function of other immune cells and directly attack various infected cells and tumors. B lymphocytes make antibodies, which are proteins that specifically target bacteria, viruses, and other foreign materials.

Platelets (also called thrombocytes)

Unlike red and white blood cells, platelets are not actually cells but rather small fragments of cells. Platelets help the blood clotting process (or coagulation) by gathering at the site of an injury, sticking to the lining of the injured blood vessel, and forming a platform on which blood coagulation can occur. This results in the formation of a fibrin clot, which covers the wound and prevents blood from leaking out. Fibrin also forms the initial scaffolding upon which new tissue forms, thus promoting healing.

A higher than normal number of platelets can cause unnecessary clotting, which can lead to strokes and heart attacks; however, thanks to advances made in antiplatelet therapies, there are treatments available to help prevent these potentially fatal events. Conversely, lower than normal counts can lead to extensive bleeding.

Complete Blood Count (CBC)

A complete blood count (CBC) test gives your doctor important information about the types and numbers of cells in your blood, especially the red blood cells and their percentage (hematocrit) or protein content (hemoglobin), white blood cells, and platelets. The results of a CBC may diagnose conditions like anemia, infection, and other disorders. The platelet count and plasma clotting tests (prothombin time, partial thromboplastin time, and thrombin time) may be used to evaluate bleeding and clotting disorders.

Your doctor may also perform a blood smear, which is a way of looking at your blood cells under the microscope. In a normal blood smear, red blood cells will appear as regular, round cells with a pale center. Variations in the size or shape of these cells may suggest a blood disorder.

Normal blood smear.

The four larger cells shown are called granulocytes, a type of white blood cell.

Abnormal blood smear with variation in the size and color of the red blood cells.

Where Do Blood Cells Come From?

Blood cells develop from hematopoietic stem cells and are formed in the bone marrow through the highly regulated process of hematopoiesis. Hematopoietic stem cells are capable of transforming into red blood cells, white blood cells, and platelets. These stem cells can be found circulating in the blood and bone marrow in people of all ages, as well as in the umbilical cords of newborn babies. Stem cells from all three sources may be used to treat a variety of diseases, including leukemia, lymphoma, bone marrow failure, and various immune disorders.

Where Can I Find More Information?

If after further exploration of the Blood: The Vital Connection Web site you find that you are interested in learning more about blood diseases and disorders, here are a few other resources that may be of some help:

Articles From Hematology, the ASH Education Program Book
The American Society of Hematology (ASH) Education Book, updated yearly by experts in the field, is a collection of articles about the current treatment options available to patients. The articles are categorized here by disease type. If you are interested in learning more about a particular blood disease, we encourage you to share and discuss these articles with your doctor.

Results of Clinical Studies Published in Blood
Search Blood, the official journal of ASH, for the results of the latest blood research. While recent articles generally require a subscriber login, patients interested in viewing an access-controlled article in Blood may obtain a copy by e-mailing a request to the Blood Publishing Office.

Other Resources
This section includes a list of Web links to patient groups and other organizations that provide information.

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