Human growth hormone deficiency can affect anyone. Although it is more commonly considered to be a disorder suffered by children, adults can also experience this condition. So if you are an adult who feels that you might be suffering from HGH deficiency, how can you be sure? What investigations will your doctor have you go through to confirm the diagnosis? Understanding the disease is crucial to enable you to take more control over your condition and begin the best treatment for a healthy physical condition and lifestyle.
What Is HGH Deficiency?
Human growth hormone is produced by the pituitary gland in the brain. A deficiency of the hormone occurs when the gland does not generate a sufficient level of the hormone. Although this condition is not common in adults, it is not unknown either. The most likely causes of HGH deficiency in adults are a severe head injury, brain tumors involving the pituitary gland or hypothalamus, or undergoing radiation therapy for brain cancer.
Adults with an HGH deficiency may experience the following symptoms:
- Dry skin
- Increased weight gain and body fat, especially around the waist area
- Decreased muscle mass, tone, and strength
- Lowered energy and stamina leading to fatigue
- Baldness for males
- Higher sensitivity to temperature changes
- An increase in cholesterol, higher levels of triglycerides and fibrinogen, abnormalities in lipids, most notably a rise in LDL
- Cardiac dysfunction
- Lowered bone density leading to a higher risk of osteoporosis and more bone fractures as the individual grows older
- A decrease in sexual drive or function
- Trouble with memory and concentration
- Behavioral changes, and more feelings of anxiety, isolation, or depression.
When Should Test For Growth Hormone Deficiency?
Although you may have the symptoms of HGH deficiency, it is important to speak with your doctor in order to know for sure. There are other conditions and disorders that have similar symptoms as HGH deficiency, so your doctor might want to run other confirmatory tests first, such as checking the levels of testosterone, TSH, T4, LH, FSH, and cortisol. After these tests have eliminated other possible conditions, your doctor will run HGH deficiency tests.
What Are The Tests For Adult Growth Hormone Deficiency?
Next, we will take a look at the variety of HGH deficiency tests that your doctor might run. Bear in mind, however, that not all of these tests are used commonly – some might be more likely to be used in studies and research than in a doctor’s office. Many of the tests are individualized to fit certain circumstances. Endocrinologists still debate the accuracy of some tests and the usefulness of each test in a clinical setting. However, all these tests may still be used by endocrinologists to determine and treat the presence of an HGH deficiency. The number and variety of tests show how complex a diagnosis of HGH deficiency can be. The tests below are designed to distinguish the patients with normal levels of HGH from those with a deficiency.
What Is The IGF-1 Hormone Test?
IGF-1 stands for Insulin-like growth factor -1 hormone test. Endocrinologists usually order it in conjunction with GH stimulation or GH suppression tests.
The different GH Tests
The GH Stimulation Test
The GH stimulation test is intended to diagnose both HGH deficiency and hypopituitarism. The patient must take a fast for ten to twelve hours before the test. During the test, the doctor takes a blood sample, before giving the patient intravenous arginine or insulin. Afterward, the tester takes further samples of blood at set time intervals. The samples will be used to test the patient’s growth hormone levels, giving the endocrinologist an idea of whether the insulin or arginine has successfully stimulated the pituitary gland to produce a normal amount of HGH. If the tests do not show the pituitary gland as stimulated, and the patient has symptoms of HGH deficiency in conjunction with a low level of IGF-1, the endocrinologist can treat the likely deficiency. Similarly, if the patient undergoes vigorous exercise without an increase in HGH levels, then it is also likely that they are suffering from hormone deficiency. Bear in mind that tests for low levels of TSH should be run first since HGH deficiencies and thyroid deficiencies might have similar symptoms.
The GH Suppression Test
The GH suppression test, on the other hand, is intended to measure excessively high levels of HGH in the patient. It can also be used in conjunction with other blood tests and various imaging scans in order to identify tumors of the pituitary. Again, the patient must fast for at least ten and up to twelve hours before the test. Then, a blood sample is taken. Next, the patient takes a glucose solution, and later further blood samples are drawn at certain intervals of time. The levels of HGH in the blood are tested in order to see whether the glucose has suppressed the amount of hormone generated by the pituitary gland. If the HGH levels are not suppressed, and the patient has accompanying symptoms of gigantism or Acromegaly, then the person is likely to be producing excessive amounts of the hormone. Similarly, if X-rays, CT scans, or MRIs show the presence of a mass in the brain, then the patient may have a pituitary tumor. Most of the time such tumors are benign.
What Are The GH Secretion Tests?
The 24 hour GH secretion test is intended to measure the HGH levels using polyclonal radioimmunoassay. It can show significant amounts of overlap between healthy patients and those who have a hormone deficiency. The test must take place over twenty-four hours, and requires the taking of repeated samples. This can be a time-consuming process. The secretion test is noted to have a sensitivity level of ninety percent. However, for patients under forty years of age, its specificity might be seventy-nine percent, while for those who are older than sixty the specificity drops to thirty-six percent.
The GH secretion dynamic test measures the level of HGH reserve. The tester must induce hypoglycemia in the patient using an insulin bolus intravenously. Then the doctor will measure the patient’s HGH levels every fifteen minutes to half an hour for a period of one hundred and twenty minutes. After the patient’s blood glucose drops to a sufficient point of 2.2 mmol/L, polyclonal radioimmunoassay is used to track growth hormone response. A peak response of under 5 ng/mL indicates HGH deficiency, and peak response of under 3 ng/mL suggests that the deficiency might be severe. This division allows doctors to separate the responses of normal subjects from those with hypopituitarism, as well as taking into account other factors that may affect the amount of HGH the body secretes, such as obesity or age. The secretion dynamic test can indicate the necessity for adult HGH replacement therapy. However, although it is often considered “the gold standard,” this test is still not a perfect indicator. The patient might not achieve a sufficient state of hypoglycemia, and may even require hospital admission. This can consume a large number of resources in health care. Also, the intensive testing required can last as much as three or four hours, since the action of the glucagon might be delayed. Additionally, it is necessary for an experienced medical professional at a sufficiently equipped center to successfully carry out this test.
What is the Arginine test?
The Arginine test is used to measure HGH reserves. However, because the response of the hormone to this test is not very strong, it usually provides less stimulant for the release of HGH than other tests such as the GST. On the other hand, patients tend to prefer the arginine test, because it is associated with very few side effects except for minor cases of dry mouth.
For the GHRH + Arginine test, patients are given one bolus of arginine (measured at 0.5 g/kg of their overall body weight) and one bolus of GHRC (1 mcg/kg of overall weight) intravenously. It is intended to stimulate powerfully the generation of HGH in the pituitary gland, which can help doctors diagnose any deficiencies. Next, samples of serum are collected every fifteen minutes to half an hour for a period of two hours. However, there is a great deal of debate connected with this test mainly regarding the cutoff point to diagnose deficiency. According to some endocrinologists, 4.1 ng/mL is the proper cutoff, but others say that it should be 9 ng/mL. Furthermore, although most patients find this to be a safe test, with no more severe side effects than flushing, in rare cases more serious effects can occur. This test should not be given at all to patients who suffer from chronic renal failure.
If you are an adult and have symptoms that might indicate human growth hormone deficiency or you are just interested in the anti-aging HGH benefits, consult your doctor first. Hormone deficiencies can be serious – but they can be managed. Medical professionals can help you find the best treatment options for your lifestyle and provide you with the necessary knowledge about your condition.
GH Deficiency Symptoms Infographic