From the FDA Drug Label
1 INDICATIONS AND USAGE
- 2 Adult Patients Nutropin AQ is indicated for the replacement of endogenous GH in adults with GHD who meet either of the following two criteria: Adult Onset: Patients who have GHD, either alone or associated with multiple hormone deficiencies (hypopituitarism), as a result of pituitary disease, hypothalamic disease, surgery, radiation therapy, or trauma;
The patient has a pituitary adenoma and is considered growth hormone deficient. The patient's IGF1 level is 93 and z score is -0.8, which supports the diagnosis of growth hormone deficiency.
- The patient meets the criteria for Adult Onset GHD due to pituitary disease.
- According to the label, somatropin (SQ) is indicated for the replacement of endogenous GH in adults with GHD, including those with pituitary disease 1.
From the Research
This 52-year-old female with a pituitary adenoma, fatigue, headaches, IGF-1 of 93, and a z-score of -0.8 is not considered growth hormone deficient based on the current IGF-1 values alone. The IGF-1 level of 93 with a z-score of -0.8 falls within the normal range, as a z-score between -2 and +2 is typically considered normal 2. Growth hormone deficiency is generally diagnosed when IGF-1 levels are below the reference range with a z-score less than -2, often in conjunction with abnormal growth hormone stimulation testing. The patient's symptoms of fatigue and headaches, while potentially related to the pituitary adenoma, are not specific to growth hormone deficiency and could be caused by various factors including the mass effect of the adenoma itself. Some key points to consider in the management of this patient include:
- Management should focus on addressing the pituitary adenoma through appropriate neurosurgical consultation and treating specific hormonal deficiencies if present.
- If there is clinical suspicion for growth hormone deficiency despite the normal IGF-1, a growth hormone stimulation test such as insulin tolerance test or glucagon stimulation test could be considered for definitive diagnosis, as suggested by recent guidelines 2, 3.
- Growth hormone replacement therapy has been shown to have benefits in body composition, exercise capacity, skeletal integrity, and quality of life measures, but it is most likely to benefit those patients who have more severe GHD 4, 3. However, based on the current evidence, growth hormone replacement therapy would not be indicated for this patient based solely on the provided IGF-1 values. It is essential to approach the diagnosis and treatment of adult growth hormone deficiency with careful consideration of the benefits and risks specific to the individual, as emphasized in recent reviews and guidelines 2, 5, 3.