Growth hormone deficiency
Growth hormone (GH) deficiency causes short stature in children and a nonspecific syndrome of fatigue, reduced muscle mass, and adverse body composition in adults, usually from hypothalamic-pituitary disease, surgery, irradiation, or head trauma. Diagnosis relies on a low age-adjusted IGF-1 with confirmatory provocative testing when needed, and treatment is daily subcutaneous somatropin titrated to a normal IGF-1, avoided in active malignancy or an untreated pituitary tumor.
- Topic reviewThe full article, organized the way the exam asks it.
- ABIM-format MCQsVignettes with an explanation for every wrong answer.
- Key factsThe numbers and thresholds worth memorizing, up front.
- AI tutorMedBrain answers the question you're stuck on.
What this article covers
- Overview
Growth hormone (GH) deficiency is inadequate GH secretion from the anterior pituitary, producing short stature and growth failure in childhood and a nonspecific syndrome of fatigue, adverse body…
- Epidemiology
Adult-onset GH deficiency is uncommon in the absence of a recognized hypothalamic-pituitary disorder; idiopathic isolated adult GH deficiency is rare, which is why testing is reserved for patients…
- Risk factors
A history of hypothalamic or pituitary disease (tumor, infiltrative or inflammatory disease, or a structural lesion) is the leading risk factor for adult GH deficiency.
- Pathophysiology
GH is secreted by somatotroph cells of the anterior pituitary under stimulatory control by hypothalamic GH-releasing hormone (GHRH) and inhibitory control by somatostatin.
- Clinical features
In adults, the presentation is nonspecific and subtle: fatigue, reduced muscle mass and strength, and more fat relative to lean body mass, often with low bone density, adverse lipid profile, and impaired quality of life or mood.
- Differential diagnosis
Primary hypothyroidism: shares fatigue, weight gain, and reduced energy, but is distinguished by an elevated TSH with low free T4, rather than a low IGF-1 with an appropriate or low TSH.
- Diagnosis
The diagnosis rests on a low age- and sex-adjusted serum IGF-1 in a patient with a plausible cause, with provocative GH testing reserved for equivocal cases; a normal IGF-1 does not exclude the…
- Management
First, correct any coexisting ACTH deficiency with hydrocortisone 15-20 mg PO daily in two divided doses, lifelong, before starting other hormone replacement, because untreated secondary adrenal…
- Complications
Low bone mineral density and fracture risk from chronically low IGF-1 and its effects on bone turnover.
- Prognosis
GH replacement improves muscle strength, body composition, bone density, and quality of life in adults with confirmed deficiency, though long-term effect on cardiovascular outcomes and mortality is not established.
- Prevention
Assess pituitary function (including IGF-1, TSH, free T4, cortisol, and testosterone in men) at 3 to 6 months and then yearly for at least 3 years in patients with moderate to severe traumatic brain…
Read the whole article
Subscribing to Internal Medicine opens every article, the full question bank and MedBrain, on the web, iPhone and Android.
Related articles
- Nonfunctioning pituitary adenoma
A nonfunctioning pituitary adenoma is a benign pituitary tumor, usually of gonadotroph origin, that does not secrete a clinically excessive hormone and presents through mass effect (visual field loss, headache) or hypopituitarism rather than a hypersecretory syndrome. Diagnosis requires excluding hormone excess and screening for hypopituitarism; treatment is observation for a small asymptomatic incidentaloma or transsphenoidal surgery for mass effect, apoplexy, or growth on follow-up.
- Acromegaly
Acromegaly is acral and soft-tissue overgrowth from chronic growth hormone excess, almost always caused by a GH-secreting pituitary adenoma, diagnosed with an elevated IGF-1 confirmed by failure of GH suppression on an oral glucose tolerance test. First-line treatment is transsphenoidal resection of the pituitary tumor, with somatostatin analogues, pegvisomant, or cabergoline for persistent disease.
- Central diabetes insipidus
Central diabetes insipidus is inability of the posterior pituitary to produce adequate antidiuretic hormone, causing free water loss, polyuria, and hypernatremia; common causes include pituitary/hypothalamic tumor, surgery, trauma, and infiltrative disease. Diagnosis is confirmed with a water deprivation test followed by a desmopressin challenge, and treatment is desmopressin (DDAVP) 10-40 mcg intranasally or 0.1-0.4 mg orally, dosed once nightly or twice daily and titrated to control polyuria while avoiding dilutional hyponatremia from over-replacement.