The healthy and happy growth of children has always attracted the attention and attention of parents, especially the physical development and height growth of children, which tugs at the heartstrings of every parent. A child's height is determined by genes, living environment, nutritional conditions, exercise, endocrine factors, etc., and some diseases can lead to the appearance of "short stature".
Children with short stature need to be scientifically judged by professional clinicians in combination with genetic height, current height, growth rate, bone age, sexual development status, laboratory evaluation, etc., to improve their final height.
In a similar growth environment, if a child's height is 2 standard deviations lower than the average height of normal children, or if the height is less than the 3rd percentile of the height of children in the same population, it is called short stature.
01. Reliable indicators of IGF-1 and IGFBP-3 in the diagnosis of ghd.
Causes of short stature** include growth hormone deficiency (GHD), idiopathic short stature, hypothyroidism, puberty retardation, Turner syndrome, precocious puberty, and small-for-gestational-age (SGA). Among them, GHD is a common cause of growth retardation and short stature in children**, and early diagnosis and application of genetically recombinant human growth hormone (RHGH)** can effectively improve final height.
Under normal physiological conditions, the body's growth hormone (GH) is secreted in a pulse, which is related to the integrity of the pituitary gland, hypothalamus, neurotransmitters and brain structure and function, with obvious individual differences, and is affected by sleep, exercise, feeding and stress, so the measurement of a single GH level can not truly reflect the secretion of GH in the body.
Insulin-like growth factor 1 (IGF-1) and insulin-like growth factor-binding protein 3 (IGFBP-3) rely on GH to stimulate growth, and the level in the blood is quite stable, and there is no obvious pulse secretion and circadian rhythm changes, which can better reflect the endogenous GH secretion of the body.
02. What are IGF-1 and IGFBP3?
IGF-1, short for Insulin-like Growth Factor-1, is a peptide hormone secreted by the liver and other tissues that promotes cell proliferation, differentiation, and metabolism. The secretion of IGF-1 is regulated by growth hormone (GH), so IGF-1 can reflect the secretion level and effect of GH.
IGFBP-3, short for Insulin-like Growth Factor Binding Protein 3, is a protein that binds to IGF-1 and protects IGF-1 from degradation, prolongs its half-life, facilitates its transport in the body, and regulates its interaction with receptors. IGFBP-3 secretion is also affected by GH, so IGFBP-3 can also be used as an indirect indicator of GH.
03. How to detect IGF-1 and IGFBP-3?
A common method for the detection of IGF-1 and IGFBP-3 is to collect a fasting venous blood sample and analyze it using electrochemiluminescence immunoassay.
04. How to understand the test results?
The test results need to be compared with the corresponding normal reference range according to different factors such as age, gender, height, weight, pubertal development stage, etc., to determine whether it is normal or abnormal. At present, some studies at home and abroad have established the normal reference range of IGF-1 and IGFBP-3 in different populations, but there are still some differences and limitations, which need to be selected and adjusted according to the actual situation.
In general, the levels of IGF-1 and IGFBP-3 are positively correlated with the levels of GH, i.e., when GH secretion increases, the levels of IGF-1 and IGFBP-3 also increase, and vice versa.
Therefore, if IGF-1 and IGFBP-3 levels are significantly below the normal range, GH secretion may be inadequate, and further GH provocation testing is required to confirm the diagnosis of GHD; Levels of IGF-1 and IGFBP-3 that are significantly higher than the normal range may indicate GH hypersecretion and require further GH suppression testing to confirm the diagnosis of acromegaly.
Of course, the levels of IGF-1 and IGFBP-3 can also be affected by other factors, such as nutritional status, degree of obesity, thyroid function, sex hormone levels, kidney function, liver function, diabetes, medications, etc. Therefore, the test results need to be combined with comprehensive analysis of clinical manifestations, medical history, physical examination, other laboratory tests, etc., in order to make a correct diagnosis and decision-making.
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