What Is IGF-I Test?
IGF-I is a hormone produced primarily in the liver and plays a crucial role in growth and development. It is closely linked to growth hormone (GH) levels, as GH stimulates the production of IGF-I. This test is often used to evaluate growth disorders, such as gigantism or dwarfism and to diagnose or monitor conditions related to the pituitary gland, such as acromegaly or growth hormone deficiency.
The test is also helpful in assessing nutritional status, as IGF-I levels can be affected by malnutrition or chronic illnesses. Additionally, it is used to monitor the effectiveness of growth hormone therapy in patients with growth hormone deficiencies. By measuring IGF-I levels, healthcare providers can gain insights into the body’s growth hormone activity and identify potential endocrine disorders.
How is the Test Performed?
Sample Collection
The test requires a blood sample drawn from a vein of the patient.
Lab Testing
The sample is sent to our laboratory, where it is analyzed using advanced immunoassay techniques to measure IGF-I concentration.
Processing Time
Results are typically available within a few hours to a couple of days, depending on the type of test.
What are the symptoms that prompt this test?
Symptoms vary according to age and gender. The most common symptoms that warrant this test are:
Men
- Reduced muscle mass
- Fatigue and low energy
- Decreased libido
- Unexplained weight gain or loss
- Osteoporosis or weak bones
Women
- Irregular menstrual cycles
- Hair thinning or loss
- Low bone density
- Unexplained fatigue
- Difficulty losing or gaining weight
Children
- Delayed growth and development
- Short stature compared to peers
- Delayed puberty
- Poor muscle development
Elderly
- Increased frailty
- Muscle weakness
- Reduced bone density
- Cognitive decline
What are Normal Ranges for This Test?
Normal IGF-I levels vary by age, sex and laboratory standards. Below are general ranges:
Men
- Ages 16~24g 182–780 ng/mL
- Ages 25~39 114–492 ng/mL
- Ages 40~54 90–360 ng/mL
- Ages 55 and older 71–290 ng/mL
Women
- Ages 16~24g 187–859 ng/mL
- Ages 25~39 116–490 ng/mL
- Ages 40~54 93–354 ng/mL
- Ages 55 and older 75–280 ng/mL
**The above mentioned range is for information purpose only. Normal levels are dependent on a number of factors including age, gender how the test is performed and health condition of patient etc. Result interpretation should be done by a qualified doctor or healthcare professional.**
What Happens if Test Results Show Abnormal Levels?
Abnormal IGF-I levels may indicate growth hormone disorders, liver disease or nutritional deficiencies. If results are high, conditions like acromegaly or gigantism may be suspected, requiring additional testing such as GH suppression tests or MRI scans. If results are low, growth hormone deficiency, malnutrition or chronic illness could be the cause, prompting further endocrine evaluations.
A doctor may recommend additional hormone tests, imaging studies or specialized treatment plans based on the results.
