Generality
Androstenedione is a hormone secreted in plasma by the adrenal glands, the testicle in men and the ovary in women. This hormone is produced as an intermediate in the biochemical pathway that leads to the synthesis of testosterone, estrone and estradiol.
Androstenedione can be used as a marker of adrenal, testicular and ovarian function, and allows the evaluation of androgen production.
Elevated blood levels can be found in the presence of adrenal hyperplasia, polycystic ovary, and various neoplastic processes.
In adult men, an excess of androstenedione does not cause macroscopic signs, but in women it can cause virilization (appearance of male secondary characters) and amenorrhea.
Androstenedione is one of the sex hormones responsible for differentiating male and female characteristics (such as a beard and a deep voice in a man).
An excess of this hormone or other androgens can cause abnormalities in the genital organs of children, hirsutism (excess body hair), changes in the menstrual cycle in girls and precocious puberty in boys.
What's this
Androstenedione, or 4-androstenedione, is a steroid hormone with 19 carbon atoms, produced by the adrenal gland and gonads. A small amount is also synthesized at the peripheral level, starting from specific precursors (dehydroepiandrosterone and 17-hydroxyprogesterone).
In turn, andostrenedione is the precursor of estradiol and estrone (female sex hormones), and of the androgen testosterone (male sex hormone par excellence). This characteristic limits the possibilities of use of androstenedione as a pro-hormone capable of increasing serum testosterone levels; the simultaneous increase in conversion to estrogen tends to cancel the alleged anabolic (increase in muscle mass) and ergogenic (increase in strength) effects.
In the female, androstenedione is produced, under the stimulus of the pituitary gonadotropins, by the theca cells, and readily converted into oestrone by the granulosa cells. Both these cells are part of the ovarian follicle, that is, the structure containing the egg cell and its lining The outermost layer of the follicle consists of theca cells, the innermost layer of granulosa cells.
The adrenal synthesis of androstenedione - in percentage terms higher after menopause - occurs under stimulation of the pituitary ACTH.
Because it is measured
The androstenedione test is useful when it is necessary:
- Assess the functionality of the adrenal glands;
- Establish the cause of virilization (appearance of male secondary characters) in females and signs of precocious puberty in male children (hirsutism, lowering of the voice, increased musculature and increased size of the genitals);
- Testing for androgen production and gonadal function (i.e. of the ovaries and testes).
The determination of androstenedione can be indicated by the doctor at the same time or after other tests - such as the testosterone and 17-OH progesterone test - when there is an overproduction (or, more rarely, a deficiency) of androgens.
Androstenedione can also be measured if puberty is late in appearing or when the woman has infertility, in the presence of signs such as hirsutism (abundant hair on the face and body), acne, absence of menstruation (amenorrhea) or irregular menstruation and baldness with typically male alopecic site.
Androstenedione dosage can also be used to periodically monitor glucocorticoid treatment for congenital adrenal hyperplasia.
Normal values
Physiological plasma levels of Androstenedione
Babies
20-290 ng / dL or 0.7-10.1 mmol / L
Pre puberty
8-50 ng / dL or 0.3-1.7 mmol / L
Adult women
75-205 ng / dL or 2.6-7.2 mmol / L
Adult men
85-275 ng / dL or 0.3-9.6 mmol / L
Women in the postmenopausal period
Reference values may vary from laboratory to laboratory
Androstenedione Alto - Causes
Although the androgenic activity of the hormone is only 1/5 of that of testosterone, high serum levels of androstenedione in women are often associated with acne, hirsutism, virilization and androgenetic baldness.
Values higher than the reference values, especially if associated with elevated luteinizing gonadotropin (LH), point towards a possible diagnosis of polycystic ovary syndrome (Stein-Leventhal syndrome), while in Cushing's syndrome they are accompanied by hypercortisolism.
Very high values (> 30 nmol / L) may suggest a hormone-secreting adrenal or ovarian tumor.
Androstenedione Basso - Causes
Lower than normal androstenedione values are typical of adrenal insufficiency.
How it is measured
To measure androstenedione levels, the patient must have blood drawn from a vein in the arm.
Preparation
Before undergoing the sample useful for the determination of androstenedione, it is necessary to observe a fast of at least 8 hours. During this period, a modest quantity of water is allowed.
Levels of androstenedione in the blood vary throughout the day and during the ovarian cycle in women. Therefore, in fertile women, it is indicated to undergo the examination one week before or after the onset of menstruation.
Interpretation of Results
- A normal concentration of androstenedione in the blood, coupled with an adequate result of other adrenal activity tests, should indicate that the glands are functioning properly.
- An "increased concentration of androstenedione in the blood signals an increase in production by the adrenal glands, ovaries or testes. A high level of this hormone is not diagnostic in itself, but indicates the need to investigate the clinical picture with further investigations. An increase in androstenedione may in fact depend on various conditions, including adrenal tumors and polycystic ovary syndrome (PCOS).
- A low concentration could indicate adrenal, ovarian, or testicular dysfunction.
Androstendione can be included in the anti-doping test panel. Sometimes, in fact, this hormone can be illegally taken as a drug by athletes to improve their performance. As with other anabolic steroids (synthetic analogues of testosterone), this practice is not without its negative consequences, including cardiovascular disease and liver damage.
Select Blood Tests Blood Tests Uric acid - uricaemia ACTH: adrenocortitotropic hormone Alanine amino transferase, ALT, SGPT Albumin Alcoholism Alphafetoprotein Alphafetoprotein in pregnancy Aldolase Amylase Ammonemia, ammonia in the blood Androstenedione Antibody-endomysial antibodies Anti-gliadicides Nucleus Helicobacter pylori antibodies Embryo carcinoal antigen - CEA Prostate specific antigen PSA Antithrombin III Haptoglobin AST - GOT or aspartate aminotransferase Azotemia Bilirubin (physiology) Direct, indirect and total bilirubin CA 125: tumor antigen 125 CA 15-3: tumor antigen 19-9 as tumor marker Calcemia Ceruloplasmin Cystatin C CK-MB - Creatine kinase MB Cholesterolemia Cholinesterase (pseudcholinesterase) Plasma concentration Creatine kinase Creatinine Creatinine Creatinine clearance Chromogranin A D-dimer Hematocrit Blood culture Hemocrome Hemoglobin Glycated hemoglobin a Blood tests Blood tests, Down syndrome screening Ferritin Rheumatoid factor Fibrin and its degradation products Fibrinogen Leukocyte formula Alkaline phosphatase (ALP) Fructosamine and glycated hemoglobin GGT - Gamma-gt Gastrinemia GCT Glycemia Red blood cells Granulocytes HE4 and Cancer at "Ova" Immunoglobulins INR Insulinemia Lactate dehydrogenase LDH Leukocytes - white blood cells Lymphocytes Lipases Tissue damage markers MCH MCHC MCV Metanephrines MPO - Myeloperoxidase Myoglobin Monocytes MPV - average platelet volume Natremia Neutrophils Homocysteine Thyroid hormones OGTT Osmocyte Plasma protein A associated with pregnancy Peptide C Pepsin and pepsinogen PCT - platelet or platelet hematocrit PDW - distribution width of platelet volumes Platelets Plateletpenia PLT - number of platelets in blood Preparation for blood tests Prist Test Total IgEk Protein C (PC) - Protein C Activated (PCA) C Reactive Protein Rast Protein Test Specific IgE Reticulocytes Renin Reuma-Test Oxygen Saturation Sideremia BAC, BAC TBG - Thyroxine Binding Globulin Prothrombin Time Partial Thromblopastin Time (PTT) Activated Partial Thromboplastin Time (aPTT) Testosterone Testosterone: free and bioavailable fraction Thyroglobulin Thyroxine in the blood - Total T4, free T4 Transaminases High transaminases Transglutaminase Transferrin - TIBC - TIBC - UIBC - saturation of transferrin Transtyretin Triglyceridemia Triiodothyronine in the blood - Total T3, free T3 Troponin TRH and Troponins of s thymol to TRH TSH - Thyrotropin Uremia Liver values ESR VDRL and TPHA: serological tests for syphlis Volemia Conversion of bilirubin from mg / dL to µmol / L Conversion of cholesterol and triglyceridemia from mg / dL to mmol / L Conversion of creatinine from mg / dL to µmol / L Conversion of blood glucose from mg / dL to mmol / L Conversion of testosteronemia from ng / dL - nmol / L Conversion of uricemia from mg / dL to mmol / L
