AGHD may lead to fatigue, changes in body composition, metabolic effects, and decreased health and well-being. However, the problem is that all of these factors can be caused by any kind of hormone disorders.
This is why the AGHD is not diagnosed by its signs and even blood test results. It is evaluated with the help of the patient’s medical history, pituitary gland function and laboratory tests as well as, in many cases, the patient’s reaction to growth hormone stimulation testing.
What Is Adult Growth Hormone Deficiency?
This hormone is produced by the pituitary gland that is located in the brain’s base. Apart from the fact that the growth hormone performs several functions connected with the growth process, it is still significant for metabolism, muscles and bones, and body composition of the adult person.
Hormonal deficiency in the adult usually occurs after the diseases or damage of the pituitary gland or hypothalamus. Hormonal deficiency can be caused by tumors, surgery, irradiation of the brain or pituitary gland region, severe head injuries, or sometimes, it is present from birth.
Growth hormone levels naturally decrease with age, so a lower level in an older person is not, on its own, evidence of AGHD.
Growth Hormone Deficiency Adult Symptoms
Symptoms may be very hard to recognize. They may include constant feeling of tiredness, low energy levels, less ability to do physical exercise, low muscle mass, high body fat, particularly in the abdominal region, and low bone density. There are some reports of lowered feeling of well-being.
No symptom is sufficient enough to diagnose the disorder. Fatigue may have various causes including problems in sleeping, anemia, thyroid dysfunction, medications, depression, illness, or any other reason. Also, changes in the body composition may occur because of dieting, physical inactivity, aging, or any other metabolic disorder.
Who Should Be Tested for Growth Hormone Deficiency?
In most cases, physicians will not suggest the growth hormone deficiency test because the patient complains of fatigue and excess fat in their abdomen. The diagnosis of growth hormone deficiency will be more relevant to the case if the mentioned symptoms appear in a person who has a risk factor associated with hypothalamic or pituitary disease.
The mentioned risk factors might include the history of a pituitary tumor, surgical intervention in the pituitary gland, radiotherapy of pituitary gland or its close proximity, severe brain trauma, or pituitary hormone deficiency. People who have had treatment for growth hormone deficiency during childhood may require testing again when they reach adult size based on the underlying cause of the deficiency.
An endocrinologist will consider all these issues together with medications, other hormone levels, and possible causes of symptoms before determining whether the patient requires special testing. Stimulation tests may not be required in selected individuals with a proven genetic or structural cause, or in those with known hypothalamic-pituitary disease, at least three other pituitary hormone deficiencies, and an unambiguously low IGF-1.
Importance of Correct Diagnosis Before Treatment
The use of growth hormone replacement therapy is meant to be prescribed only to individuals who have been diagnosed with medically proven deficiency, but not for those experiencing tiredness, aging, body building, or weight loss. It depends on whether the treatment should be used based on a comprehensive medical evaluation.
How Is Adult Growth Hormone Deficiency Diagnosed?
History and Hormone Screening
The initial assessment typically includes symptoms, a review of the patient’s history, and pituitary function testing. The IGF-1 test is one of the screening tests done for this condition. The insulin-like growth factor 1 or IGF-1 is affected by growth hormone and tends to remain relatively constant in comparison to the growth hormone.
In some cases, a low IGF-1 is enough in the presence of the correct clinical scenario, but the test is not conclusive on its own. Similarly, a normal IGF-1 may not necessarily negate growth hormone deficiency in adults.
It is crucial to verify the level of IGF-1 relative to the reference range according to age from the laboratory where the test was carried out. IGF-1 levels can be low due to diabetes that is not well-managed, diseases of the liver, malnutrition, and oral intake of estrogen, hence the need to consider such factors while interpreting the result.
Growth hormone screening using one random test is inconclusive because the hormone is secreted in pulses by the pituitary gland.
Growth Hormone Stimulation Tests
For confirmation of deficiency, there are growth hormone stimulation tests that help to stimulate the production of growth hormone and evaluate the response via blood tests.
Prior to a stimulation test, it is important to make sure that all other pituitary hormone deficiencies have been addressed and stabilized, as inappropriate treatment or dosing will interfere with the test.
The ITT or insulin tolerance test has long been considered the reference test for adults, although it intentionally produces hypoglycemia and thus requires medical supervision. Patients who have seizures in their past or serious cardiovascular disease may be unable to perform this test. Other choices include the glucagon stimulation test and oral macimorelin test. It depends on the patient’s medical history and contraindications.
Interpretation of the Test Results
The endocrinologist looks into the results in context instead of focusing on just a single number. The testing method, patient age, patient body mass, presence of other diseases, and probability of pituitary disease may affect the interpretation.
Patient obesity, for instance, is known to decrease stimulated growth hormone levels, while different stimulation tests have different cut-off points for diagnosis. Thus, the growth hormone deficiency in adults diagnosis will be a result of biochemical testing plus the clinical profile.
What Happens After a Growth Hormone Deficiency Diagnosis?
Treatments for Established Growth Hormone Deficiency
There may be some adults who have been diagnosed with AGHD and would benefit from growth hormone replacement therapy. Somatropin is the man-made version of growth hormone for humans. Norditropin is one brand of somatropin that can be used for adults who suffer from growth hormone deficiency.
Adult growth hormone deficiency treatment is personalized. It requires an assessment of the adult’s condition by an endocrinologist in consideration of diagnosis, age, medical conditions, hormone deficiencies, drug use, and contraindications. Growth hormone is not an approved treatment for anti-aging or performance enhancement among adults without growth hormone deficiency.
Monitoring Treatment and Managing Side Effects
Follow-up is an integral part of the treatment process. The clinician can measure IGF-1 levels, the severity of the symptoms, treatment effectiveness, and side effects, making necessary changes to the treatment.
Some of the possible side effects of the growth hormone replacement are fluid retention, edema, joint or muscle pain, and alterations in glucose metabolism. Glucose levels need to be monitored, as the treatment can lead to a decreased insulin sensitivity. Thyroid and adrenal gland functions need to be evaluated, as growth hormone replacement can unmask or increase central hypothyroidism and adrenal insufficiency.
When Should You Speak With an Endocrinologist?
It may be beneficial to consult with a health professional about AGHD if you have ongoing symptoms which are interfering with your day-to-day activities and also have risk factors for pituitary problems. Make sure to include information on past pituitary tumors or pituitary surgery, brain irradiation, serious head trauma, childhood GHD, and known hormone disorders.
Your doctor can exclude more likely reasons for fatigue and/or body composition issues and send you to an endocrinologist as needed. The endocrinologist who will evaluate your hormone deficiencies will know whether an IGF-1 test, pituitary function tests, imaging studies, or stimulation tests are needed.
