The diagnosis of adult growth hormone deficiency requires the presence of symptoms as well as a failure of GH to rise appropriately after an insulin or other appropriate stimulation test.
GH is often the first anterior pituitary hormone to be lost following pituitary damage. Radiotherapy is particularly associated with GH deficiency.
Radiotherapy is widely used and highly effective in cancer management, and many more adults are now survivors of previous cancer. However, cranial and craniospinal irradiation for childhood haematological malignancy, bone marrow transplants, or intracranial tumours, does increase the risk of hypopituitarism developing, and GH deficiency tends to be the first manifestation of this.
Multiple, rather non-specific symptoms may occur in the syndrome of adult GH deficiency, though none are diagnostic of it. The QOL-AGHDA disease specific questionnaire has been specifically developed to seek symptoms of adult GH deficiency. Scores above 11/25 are required to qualify for GH replacement therapy according to NICE guidelines.
This is a commonly reported feature of adult GH deficiency.
This is a commonly reported feature of adult GH deficiency, as well as a general lack of energy and concentration.
This may occur in the syndrome of adult GH deficiency, and is most likely to be recognised by completing the QOL-AGHDA questionnaire.
This is a commonly reported feature of adult GH deficiency, as well as a general lack of energy and concentration.
This may occur in the syndrome of adult GH deficiency, though is obviously not specific to it.
This may be detected on close questioning.
Osteoporosis is more common in pituitary patients. It often occurs in the context of supraphysiological glucocorticoid replacement, though is also exacerbated by GH deficiency, or thyroxine excess.
Increased central adiposity, with loss of lean muscle bulk, may occur with GH deficiency.
This may improve with GH replacement therapy.
GH is frequently the first manifestation of anterior pituitary failure. However, GH replacement should only be considered after all other axes have been tested and replaced if necessary.
Weight loss, fatigue, dizziness, cold intolerance, amenorrhoea, erectile dysfunction, loss of libido and hot flushes are all features suggestive of anterior pituitary hormone deficiency.
Hyperprolactinaemia occurs in multiple pituitary pathologies, and so may accompany GH deficiency. Gynaecomastia, erectile dysfunction and loss of libido are common presentations in male patients, amenorrhoea and galactorrhoea are the usual early presentations in female patients.
Non functioning pituitary tumours may also lead to anterior pituitary failure, and so a thorough assessment for mass effects is mandatory.
Estrogen replacement therapy of any preparation will lead to elevations in cortisol binding globulin and so effect serum cortisol results.
Inhaled and topical steroids also affect the hypothalamic-pituitary-adrenal axis, and steroids may occasionally be found in preparations thought by the patient to be 'natural' or 'herbal'.
This occurs most frequently during initial dose titration, is usually transient, and if necessary reverses on dose reduction.
This is a symptom of GH excess, but is rare in patients on replacement therapy.
This should prompt dose reduction.