Type of test Blood

Normal findings

Adults: 42-110 ng/mL

 Children:

Test explanation and related physiology

Growth hormone (GH) exerts its effects on many tissues through a group of peptides called somatomedins. The most commonly tested somatomedins are insulin-like growth factor 1 (IGF-1) and IGF-3. Measurement of free IGF-1 and IGF binding protein (BP) 3 is preferred to GH measurements in cases of short stature in early adolescence. IGF is the test of choice in identifying and monitoring treatment of acromegaly.

Great variation in GH secretion occurs during the day. A random GH assay result may significantly overlap between normal and abnormal values. To diminish the common variations in GH secretion, screening for IGF-1 provides a more accurate reflection of the mean plasma concentration of GH. Somatomedins are not affected (as GH is) by the time of day, food intake, or exercise because they circulate bound to proteins that are durable or long-lasting. Normally there is a large increase during the pubertal growth spurt.

Levels of IGF-1 depend on levels of GH. As a result, IGF-1 levels are low when GH levels are deficient. Nonpituitary causes of reduced IGF-1 levels include malnutrition, severe chronic illnesses, severe liver disease, hypothyroidism, renal failure, inflammatory bowel disease, and Laron dwarfism. Abnormally low-test results require an abnormally reduced or absent GH during a GH-stimulation test to make the diagnosis of GH deficiency.

Pediatricians commonly use IGF BPs to even further diminish the influence of the variables affecting GH and somatomedin levels. Specifically, IGF BP 2 and IGF BP 3 are the most commonly measured. However, if GH deficiency is strongly suspected yet documentation using GH or somatomedins is questionable, IGF BP determinations are helpful. IGF BP 3 is less age-dependent and is the most accurate (97% sensitivity and specificity). These proteins help to evaluate GH deficiencies and GH-resistant syndromes (e.g., Laron dwarfism). Finally, these binding proteins are very useful in predicting responses to therapeutic exogenous GH administration.

 Interfering factors

* Drugs that may cause decreased levels include high doses of estrogens.

Procedure and patient care

 • See inside front cover for Routine Blood Testing.

 • Fasting: yes

• Blood tube commonly used: lavender or red

Abnormal findings

Increased levels

- Acromegaly

- Gigantism

- Hyperpituitarism

- Obesity

- Pregnancy

- Precocious puberty

Decreased levels

- GH deficiency/resistance

- Laron dwarfism

- Inactive GH

- Resistance to somatomedins

- Nutritional deficiency

- Delayed puberty

- Pituitary tumor

- Hypopituitarism

- Cirrhosis of the liver

اخر الاخبار

اخبار العتبة العباسية المقدسة

قسم الشؤون الدينية يُطلق دورة فقهية دينية لملاكات مستشفى الكفيل

شعبة فاطمة بنت أسد للدراسات القرآنية تعلن نتائج مسابقة (ميثاق الرسول)

شعبة الخطابة الحسينية النسوية تنظّم مسابقة فرقية لطالبات برنامج ثمار العطاء

قسم العلاقات ينظم ورشة عن فن الإقناع والتواصل الفعّال للطلبة المنسقين

المزيد

الآخبار الصحية

تغيير بسيط في نمط التفكير قد يحدث فرقا كبيرا لصحة الدماغ ؟

لماذا ينعشنا المشروب الساخن في الطقس الحار؟

علماء يكتشفون فئة دم فريدة من نوعها في العالم !

لماذا ينصح الأطباء بزيت الزيتون يوميا؟

المزيد

الآخبار التكنلوجية

حساس الإطارات.. ما هو وعلامات تلفه وكيفية صيانته؟

ما معنى أودي Quattro؟ سر الأداء والتميز الهندسي ؟!

فصل الشاحن أم الهاتف أولا؟.. عادات بسيطة تطيل عمر البطارية

تعود للقرن الرابع قبل الميلاد.. اكتشاف بقايا "إيمت" المصرية

المزيد

مواضيع ذات صلة

lactic acid (Lactate)

ischemia-modified albumin (IMA)

iron level and total iron-binding capacity (Fe and TIBC, Transferrin saturation, Transferrin)

Platelet Indices and Platelet Count

Red Cell Distribution

Flow Cytometry

intrinsic factor antibody (IF ab)

insulin assay

immunoglobulin quantification

Diagnosis of Familial Dyslipidemia

Lipid Profile

5-hydroxyindoleacetic acid (5-HIAA)