Acromegaly

Clinical information

There are many different reasons for growth disorders in children, adolescents and adults. Around 3% of children show too little, too early or too much length growth and are considered auxologically conspicuous. In many cases, these are just deviations from the norm that require no treatment. However, growth disorders can also be a first sign of underlying chronic illnesses. These require treatment and must be excluded by differential diagnosis.

Diagnostics

Growth disorders can have a genetic or environmental cause or be a consequence of chronic diseases such as Crohn’s or coeliac disease. In rare cases, psychosocial or diet-related causes or hormone disorders are responsible for growth disorders. Finding the underlying cause is therefore the primary focus of growth disorder diagnostics.  

Growth hormone (GH) is one of the several essential hormones secreted by the pituitary gland and is crucial for the regulation of growth. GH has direct effects in some parts of the body but mainly stimulates production of insulin-like growth factor-I (IGF-I) in the liver. IGF-I, in turn, mediates many of the anabolic and metabolic actions of GH.   

Due to the variable levels of GH secretion and its short half-life, single measurements of circulating GH are less meaningful in the assessment of growth-related disorders. Diagnosis is usually confirmed by dynamic testing, i.e. a stimulation or suppression test. The levels of the substances which are under the control of GH (e.g. IGF-I and II, IGFBP-2 and -3, ALS) can also be used as an indirect assessment of GH secretion in the diagnosis of patients with GH disorders. IGF-I and IGBP-3, however, represent the key markers for the evaluation of growth hormone status. 

Endocrine-related tall stature is caused by hypersecretion of IGF-I. In children and adolescents this hormone excess often causes changes of appearance, manifesting as excessively tall stature (so-called gigantism), while in adults it often leads to growth of certain parts of the body, so-called acromegaly.  

The IGF-I concentration can be determined to diagnose growth disorders more rapidly and to monitor growth hormone treatment. A key requirement in assessment of IGF-I levels is the comparison to detailed reference ranges to allow appropriate target values. A unique group of 15,000 subjects was used to establish the most extensive IGF-I reference intervals which are available with the IDS IGF-I assay. 

The unique specificity of the IDS GH assay allows its use in monitoring endogenous GH levels in acromegalic patients during Pegvisomant therapy. It also allows monitoring of GH levels in pregnant females as it does not cross-react with placental GH.  

An extensive number of scientific literature describing the IDS Growth panel assays provides the best support to clinicians for optimal patient care.  

Information material

Growth