IGF-1, LC/MS

Description: Insulin-like growth factor is a test that is testing for the amount of IGF in the blood. It is used to determine if there is a lack of IGF, causing growth to be slow and underdeveloped for the age, or less likely and excesses causing too much growth for the age. It can also be used to monitor growth hormone treatments.

Also Known As: Insulin-like Growth Factor 1 Test, Somatomedin-C Test, IGF1 Test, IGF-I Test, IGF Test

Collection Method: Blood Draw

Specimen Type: Serum

Test Preparation: No preparation required

When is a IGF-1 test ordered?

IGF-1 testing is ordered in conjunction with a GH stimulation test when:

• A youngster has GH deficient signs such as delayed growth and reduced stature.

• Impaired bone density, weariness, undesirable changes in cholesterol levels, and reduced exercise tolerance are among the symptoms that a health practitioner suspects are caused by a GH deficit in adults. However, in adults with these symptoms, testing for IGF-1 insufficiency is not standard; GH and IGF-1 deficiency are both extremely rare causes of these illnesses.

When a doctor suspects someone has an underactive pituitary gland, an IGF-1 test may be requested, as well as at regular intervals to monitor individuals on GH medication.

When a child develops symptoms of gigantism or an adult shows evidence of acromegaly, IGF-1 testing may be requested along with a GH suppression test.

When a GH-producing pituitary tumor is discovered, GH and IGF-1 tests are performed after the tumor has been surgically removed to see if all of the tumor has been eliminated. When someone is enduring the medication and/or radiation therapy that usually follows tumor resection, IGF-1 is also ordered at regular intervals.

IGF-1 levels can be tested at regular intervals for many years to track a person's GH production and look for recurrence of a pituitary tumor.

What does a a IGF-1 blood test check for?

Insulin-like growth factor-1 is a hormone that, together with growth hormone, aids in the normal growth and development of bones and tissues. The test determines how much IGF-1 is present in the blood.

In response to GH stimulation, the liver and skeletal muscle, as well as many other tissues, create IGF-1. Many of GH's activities are mediated by IGF-1, which promotes the growth of bones and other tissues as well as the synthesis of lean muscle mass. It's difficult to interpret the findings of a single GH test because GH is released into the blood in pulses throughout the day. IGF-1 levels are similar to GH excesses and deficiencies, however unlike GH, they are steady throughout the day. As a result, IGF-1 can be used to estimate average GH levels. As a result, the IGF-1 test is frequently used to determine if a person has GH deficit or excess.

IGF-1 levels, like GH, start low in early childhood, progressively rise throughout childhood, peak at puberty, and then fall in adulthood. A malfunctioning pituitary gland with diminished pituitary hormones or the presence of a non-GH-producing pituitary tumor that destroys hormone-producing cells can induce GH and IGF-1 deficiencies. Where there is a lack of response to GH, IGF-1 deficiencies can also emerge. Conditions such as starvation, hypothyroidism, sex hormone insufficiency, and chronic disorders can cause this insensitivity. Genetic GH insensitivity is quite uncommon.

Early-life IGF-1 deficit, which is usually caused by GH shortage, can stifle bone growth and development, resulting in a child who is shorter than average in stature. Reduced production in adults can result in a loss of bone density, muscular mass, and lipid levels. Adults with lower bone density and/or muscle strength, as well as elevated lipids, are not routinely tested for IGF-1 deficiency, or GH deficit. A extremely rare cause of these illnesses is GH deficit, which leads to IGF-1 deficiency.

Excess GH and IGF-1 can induce acromegaly and gigantism, two rare disorders characterized by abnormal skeleton growth and other signs and symptoms. Gigantism causes bones to grow longer in children, resulting in a person who is unusually tall and has huge feet and hands. Acromegaly is a condition that causes bones to thicken and soft tissues, such as the nose, to enlarge in adults. Both disorders can cause organ enlargement, such as the heart, as well as additional problems like type 2 diabetes, a higher risk of cardiovascular disease, high blood pressure, arthritis, and a shorter lifespan.

A GH-producing pituitary tumor is the most common cause of excessive GH secretion in the pituitary. Surgical removal of the tumor and/or treatment with medicines or radiation are frequently options. In most situations, GH and IGF-1 levels will revert to normal or near normal levels as a result of this.

Lab tests often ordered with a IGF-1 test:

• Growth Hormone

• Growth Hormone Releasing Hormone

• Glucose

• Glucose Tolerance Tests

• Total T4

• Free T4

• IGFBP-3

Conditions where a IGF-1 test is recommended:

• Pituitary Disorders

• Endocrine Syndromes

• PCOS

How does my health care provider use a IGF-1 test?

An insulin-like growth factor-1 test may be used to:

• It may be ordered in conjunction with GH stimulation testing to provide extra information a s a follow-up to abnormal hormone test findings

• Examine the function of the pituitary gland.

IGF-1 tests are less usually used to detect excess growth hormone and to diagnose and monitor the therapy of acromegaly and gigantism, two rare diseases.

IGF-1 is a hormone that, along with growth hormone, aids in the normal growth and development of bone and tissue. Along with GH, an IGF-1 test is frequently requested. IGF-1 reflects GH excesses and deficiencies, but its blood level remains constant throughout the day, making it a good measure of typical GH levels.

IGF-1 may be ordered in conjunction with other pituitary hormone assays, such as prolactin, FSH, and LH, to aid in the diagnosis of pituitary gland malfunction and low pituitary hormone levels.

A GH-producing pituitary tumor can be detected and treated using IGF-1 testing and a GH suppression test. Imaging scans that help identify and pinpoint the tumor are usually used to confirm an anterior pituitary tumor. If surgery is required, GH and IGF-1 levels are evaluated after the tumor has been removed to see if the tumor was completely eliminated. To try to reduce GH production and bring IGF-1 to a normal or near-normal concentration, drug and/or radiation therapy may be used in addition to, or sometimes instead of, surgery. IGF-1 may be ordered at regular intervals for years following treatment to monitor GH production and detect tumor recurrence and to monitor the success of this therapy.

The measurement of GH and IGF-1 levels can also provide information about GH insensitivity. If the IGF-1 level is found to be normal for age and sex before completing definitive GH testing, GH insufficiency is ruled out and conclusive testing is not required.

What do my IGF-1 test results mean?

A normal IGF-1 level must be viewed in context. Even if a person has a GH shortage, their IGF-1 level can be normal.

If the IGF-1 level is low, it's likely that you have a GH deficiency or a GH insensitivity. If this occurs in a child, the GH shortage may already have resulted in low height and delayed development, which can be corrected with GH supplementation. Adults will see a decline in production as they get older, but lower than normal levels could indicate a GH deficiency or insensitivity.

If a drop in IGF-1 is thought to be the result of a more general loss in pituitary function, multiple other endocrine glands and their pituitary-regulating chemicals will need to be assessed before treatment can be determined. Reduced pituitary function can occur as a result of genetic abnormalities or as a result of pituitary injury caused by trauma, infections, or inflammation.

Nutritional deficits, chronic kidney or liver disease, inactive/ineffective forms of GH, and excessive estrogen dosages can all cause IGF-1 levels to drop.

Greater IGF-1 levels usually imply increased GH synthesis. IGF-1 levels are a representation of average GH production, not the actual quantity of GH in the blood at the time the sample for the IGF-1 measurement was obtained, because GH levels vary throughout the day. This is correct up until the liver's capacity for IGF-1 production is achieved. The IGF-1 level will stabilize at an enhanced maximal level with drastically increased GH production.

Increased GH and IGF-1 levels are typical throughout puberty and pregnancy, although pituitary tumors are the most common cause.

If IGF-1 levels remain elevated after a pituitary tumor has been surgically removed, the surgery may not have been completely successful. The treatment is reducing GH production if IGF-1 levels decrease with successive medication and/or radiation therapies. If IGF-1 levels return to "normal," the person is no longer making excessive amounts of GH. An increase in IGF-1 levels may suggest a return of the pituitary tumor when someone is being monitored for a long time.

We advise having your results reviewed by a licensed medical healthcare professional for proper interpretation of your results.