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Acromegaly. ARUP Consult®. Retrieved May 10, 2026, https://arupconsult.com/content/acromegaly

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Acromegaly

Last Literature Review: February 2026 Last Update:

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Acromegaly is an endocrine disorder that typically results from hypersecretion of growth hormone (GH) from a dysregulated pituitary adenoma. The result is overproduction of insulin-like growth factor 1 (IGF-1). Typical clinical findings and features include abnormal musculoskeletal growth, most often noted in the face (i.e., facial disfigurement, dental abnormalities) and distal extremities, as well as arthritis, sleep apnea, hypertension, hyperhidrosis, and impaired glucose tolerance. Life expectancy is decreased as a result of related complications of the vascular, gastrointestinal, cardiovascular, and pulmonary systems, as well as malignancy. 

In rare cases, acromegaly may result from excess secretion of GH stimulated by carcinoid neuroendocrine tumors (NETs) or tumors of the hypothalamus, such as gliomas, gangliocytomas, or hamartomas.  Acromegaly can also be associated with multiple endocrine neoplasia (MEN) types 1 and 4, as well as McCune-Albright syndrome (MAS) and Carney complex (CNC). ,  Familial isolated primary adenomas or familial acromegaly may explain the presence of acromegaly in certain patients and families. 

Laboratory testing can be useful in the diagnosis of acromegaly and involves GH and IGF-1 testing. GH affects IGF-1 concentrations by acting primarily in the liver, with measurable GH concentrations resulting from the pulsatile secretions in the somatotrophs present in the pituitary adenoma.  The underlying origin of GH synthesis dysregulation in acromegaly is hormonal and/or cell cycle impacts to the somatotrophs resulting from uncontrolled cell division. 

Quick Answers for Clinicians

What is the recommended approach to evaluate gigantism in adolescents and children?

Dramatic linear growth acceleration in children or adolescents should prompt investigation for acromegaly using measurement of random serum insulin-like growth factor 1 (IGF-1), normalized for sex and age.  An elevated concentration of IGF-1 confirms the diagnosis of acromegaly in these cases. 

What advantages does the measurement of insulin-like growth factor 1 have over growth hormone measurement in the diagnosis of acromegaly?

Insulin-like growth factor 1 (IGF-1) is secreted in a continuous, nonpulsatile manner and is less subject to variability related to exercise and food intake than is growth hormone (GH).  IGF-1 is an accurate indicator of GH levels, as the two analytes are closely correlated. 

What factors are important to consider in the use and interpretation of assays for acromegaly?

Repeat testing for acromegaly should be performed by the same laboratory throughout the evaluation of the patient due to poor test standardization between test manufacturers. The assay used should be adjusted for age and sex of the patient for the greatest accuracy. , , , 

Which medical conditions or states can complicate interpretation of insulin-like growth factor 1 concentrations when assessing an individual for acromegaly?

Resistance to growth hormone (GH) within the liver may result from cirrhosis, anorexia, generalized systemic inflammation, kidney failure, chronic liver disease, or use of oral contraceptives and can affect the concentrations of insulin-like growth factor 1 (IGF-1). Impaired IGF-1 synthesis can be an effect of malnutrition, obesity, and periods of fasting, with or without the presence of acromegaly.  Refer to the Impact of Medical Conditions and States on GH and IGF-1 Concentrations table for additional factors that may impact IGF-1 as well as GH concentrations.

Diagnosis

Timely diagnosis of acromegaly is imperative to begin treatment and improve quality of life, as well as decrease mortality. ,  Clinical examination and a detailed medical history are recommended before initiation of laboratory-based testing. Biochemical testing in combination with radiologic studies support the diagnostic workup of acromegaly.

Indications for Testing

  • Acromegaly testing should be considered in adults with the following:
    • Enlarged (coarse) facial or acral features, frontal bossing, prognathism 
    • Abnormal musculoskeletal growth and uncontrolled growth of distal extremities
    • A combination of several of the following: progressive jaw misalignment, chronic headaches, sleep apnea, bony arthritis, colon polyps, carpal tunnel syndrome, diabetes mellitus type 2, cardiac disease (such as ventricular hypertrophy, hypertension, loss of vision, fatigue, and hyperhidrosis) , , , 
    • Pituitary mass , 
  • Acromegaly testing is appropriate in children with accelerated linear growth (gigantism) 

Laboratory Testing

Diagnosis

The Endocrine Society (ES) recommends measurement of IGF-1 concentrations when acromegaly is suspected due to clinical signs and symptoms that represent the classical spectrum, particularly involving facial structural characteristics (i.e., frontal bossing, coarse facial appearance). ,  IGF-1 concentrations should also be measured when less definitive features are present (e.g., diabetes mellitus, hypertension, severe arthritis, sleep apnea, hyperhidrosis). ,  Importantly, all patients with a newly diagnosed pituitary mass should have IGF-1 concentration testing performed.  If serum IGF-1 concentrations are elevated or indeterminate, a repeat test or oral glucose tolerance test (OGTT) with serial GH measurement should be performed. , ,  Elevated IGF-1 concentrations and failure of GH to suppress during an OGTT confirms the diagnosis of acromegaly.  A random GH measurement following an overnight fast has been shown to be predictive of prognosis but is not essential for making the diagnosis. 

The American Association of Clinical Endocrinology (AACE) guidelines stress that brain imaging is also important as part of the diagnostic workup, and when the optic chiasm is present, visual field testing should be performed. ,  Visual field testing is also recommended in pregnant patients with macroadenomas.  The Pituitary Society guidelines suggest that when IGF-1 or GH results are inconsistent, IGF-binding protein 3 or acid-labile subunit testing can be performed. , 

Assays for IGF-1 and GH vary, and it is important for clinicians to be aware of the means of calibration and validation, as well as how normal ranges were determined for the assay being used, and the overall assay performance. 

The following table lists conditions that may affect GH and IGF-1 concentrations.

Impact of Medical Conditions and States on GH and IGF-1 Concentrations
Elevated GH and Reduced IGF-1Elevated GH and Normal/Elevated IGF-1
Anorexia/fastingPregnancy
Exogenous estrogenPuberty
Liver diseaseUncontrolled hyperthyroidism
Renal insufficiency—
Uncontrolled diabetes mellitus—
Sources: Katznelson, 2014 ; Ogedegbe, 2022 ; Giustina, 2024 

Monitoring Therapeutic Efficacy

Biochemical testing for evidence of disease remission should be performed by measuring IGF-1 concentrations (i.e., evaluating for normalization of IGF-1 concentrations) in the first postoperative year at 3- to 6-month intervals, with follow-up monitoring for evidence of recurrence every 6-12 months thereafter. ,  OGTT results can be helpful in the event of borderline IGF-1 concentrations in patients with evidence of continuing disease. 

According to current guidelines, IGF-1 and GH concentrations that have been normalized based on patient age through therapeutic interventions (such as surgery and/or medication) are correlated with successful outcomes, including reduced morbidity and mortality. , ,  Improvement in medical therapy has also been beneficial in decreasing mortality rates and establishing remission. ,  Because of the variability of assays between laboratories and the behavior of GH after glucose suppression, however, a uniform descriptor of what constitutes a “cure” or “biochemical control” as a result of therapeutic interventions is difficult. ,  Interpreting biochemical measures in the context of presenting clinical signs and symptoms is important. 

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