Adult-onset growth hormone deficiency occurs when the pituitary gland fails to produce enough growth hormone (somatropin). It can be successfully treated with growth hormone therapy.

Alternative names for adult-onset growth hormone deficiency include such as adult growth hormone deficiency syndrome; adult GH deficiency; growth hormone deficiency; and GHD.

What is adult-onset growth hormone deficiency?

Adult-onset growth hormone deficiency is a medical condition that occurs when the pituitary gland in the brain does not produce enough growth hormone. Growth hormone is made by the anterior pituitary gland. It stimulates the release of another hormone called insulin-like growth factor 1 (IGF-1), which is produced mainly by the liver.

Together, these hormones stimulate growth in childhood (especially height) and psychological well-being and physical performance in adult life. GH also has widespread metabolic effects throughout the body.

Growth hormone deficiency is classified depending on when, or at what stage of life, the deficiency first becomes evident. There are some adults who were diagnosed as growth hormone deficient when they were children (childhood-onset growth hormone deficiency) and there are others who become growth hormone deficient once they reach adult life (adult-onset).

What causes adult-onset growth hormone deficiency?

Most cases of adult-onset growth hormone deficiency result from damage to the pituitary gland caused by a pituitary tumor or by treatment for this using surgery and/or radiotherapy. Pituitary damage can also result from:

• radiotherapy to the brain for other tumors close to the pituitary gland or for leukemia;
• from a severe head injury;
• autoimmune disease;
• from interference with the blood supply to the pituitary gland (for example, in Sheehan’s syndrome, a loss of function of the pituitary gland due to severe blood loss after childbirth, or pituitary apoplexy, sudden bleeding into the pituitary gland).

Most other types of growth hormone deficiency are caused by genetic abnormalities (e.g. Prader-Willi syndrome or Turner syndrome) or by abnormal development of the pituitary gland in the fetus. These are usually diagnosed at birth or in early childhood, but growth hormone deficiency is a lifelong condition and treatment may be needed in adult life too.

What are the signs and symptoms of adult-onset growth hormone deficiency?

Adults with growth hormone deficiency may have a wide range of symptoms. When these symptoms are severe, they can reduce people’s ability to function – both physical and psychological – and this can dramatically lower the quality of their lives.

These symptoms include:

• a decrease in the amount of muscle bulk and strength;
• increase in the amount of fat in the body (especially around the waist);
• abnormalities of ‘good’ and ‘bad’ cholesterol. This can lead to an increase in the risk of heart disease;
• abnormalities in the blood and in the circulation;
• osteoporosis (brittle bones);
• low energy levels and decreased stamina;
• impaired concentration and memory.

How is adult-onset growth hormone deficiency diagnosed?

The most common test is the ‘Insulin tolerance test’. This involves giving an injection of insulin to the patient to lower the blood sugar level. During this stress reaction, the body normally releases the growth hormone.

Failure to produce an adequate amount of growth hormone in response to this insulin-induced stress confirms growth hormone deficiency. Most patients find the test a little uncomfortable but the unpleasant symptoms do not usually last long and, if severe, can be stopped by giving glucose without invalidating the test.

The insulin tolerance test should not be carried out in patients with known heart disease or epilepsy. Alternative tests are also available in which growth hormone-releasing hormone, arginine, or glucagon are used to cause growth hormone release.

These tests should be carried out in a specialist unit, by experienced staff in performing these tests safely. The tests usually take two to four hours and can be carried out as outpatient or day case procedures. Patients may be asked not to eat before these tests.

Growth Hormone Replacement Therapy

Adult-onset growth hormone deficiency is treated with growth hormone replacement therapy. The growth hormone that is used is an artificial preparation that individuals can administer themselves. This is done using daily injections underneath the skin into the fat tissue around the lower abdomen, with an injection device.

The needles are the same as those used by people who inject insulin for diabetes and the injections are virtually painless. However, there are needle-free devices available for patients who are unable to overcome the fear of injecting. Pen delivery devices are available to administer growth hormone more reliably and some pen devices can hide the needle so well that you cannot even see it when you are giving the injection.

A doctor will calculate the dose of growth hormone appropriate for you. The dose may change depending upon your responses. It is important to note that growth hormone cannot be administered orally because it is digested in the stomach before it can be absorbed into the bloodstream.

Treatment starts as an outpatient clinic with education and support, usually from an endocrine nurse. Once started, individuals are carefully monitored and given regular blood tests. The dosage of the growth hormone is adjusted depending upon the patient’s response and results of blood tests.

Are there any side-effects of the treatment?

Side-effects from growth hormone therapy are infrequent and tend to occur when the dose is too high. Fluid retention and discomfort in the joints are reported, but decreasing the dose temporarily can relieve these symptoms. You can avoid the side effects if you follow all doctor prescriptions and never overdose on your medication.

Growth Hormone for Adults – Main Benefits

Adults with growth hormone deficiency (which may result from problems with the pituitary gland or hypothalamus) may have symptoms including:

• poor bone density (which can lead to osteoporosis if untreated);
• reduced muscle mass;
• fatigue;
• depression;
• poor memory;
• increased body fat around the waist.

They can benefit from treatment with growth hormone injections, which can help:

• increase bone density, thereby preventing fractures;
• increase muscle mass;
• increase energy levels;
• increase the capacity for exercise;
• decrease body fat;
• reduce the risk of heart disease.

The metabolic actions of growth hormone (GH) last a lifetime and involve several physiological functions associated with the control of body composition, energy metabolism, water regulation, immune response, cardiovascular performance, physical and mental work.

Chronic Fatigue and Hormone Replacement

Chronic Fatigue and lack of energy are some of the most common symptoms that cause patients to look for solutions that are often linked to hormone replacement therapy. There are many potential reasons for these symptoms. The best approach when evaluating these types of symptoms is to have a specialized hormone specialist conduct a complete evaluation, including medical history, physical examination, and diagnostic lab testing.

Adrenal Fatigue may be often mentioned in relation to adrenal system exhaustion, but there are many factors that may in fact be causing these symptoms.

The key hormones produced by the adrenal system include:

Cortisol (Glucocorticoids)

Cortisol helps control the body’s use of fats, proteins, and carbohydrates; suppresses inflammation; regulates blood pressure; increases blood sugar, and can also decrease bone formation. Cortisol also controls the sleep/wake cycle. It is released during times of stress to help your body get an energy boost and better handle an emergency situation.

Aldosterone (Mineralocorticoids)

This hormone plays a central role in regulating blood pressure and certain electrolytes (sodium and potassium).

DHEA and Androgenic Steroids (Adrenal androgens)

These hormones are precursor hormones that are converted in the ovaries into female hormones (estrogens) and in the testes into male hormones (dehydroepiandrosterone (DHEA) and testosterone).

Epinephrine (Adrenaline) and Norepinephrine (Noradrenaline)

Among other things, these hormones are capable of increasing the heart rate and blood flow to the muscles and brain, relaxing airway smooth muscles, and assisting in glucose metabolism. They also help maintain blood pressure while increasing blood pressure in response to stress.

Epinephrine and norepinephrine are often activated in physically and emotionally stressful situations when your body needs additional resources and energy to endure unusual strain.

Adrenals and Stress

When under stress, the adrenal glands produce and release bursts of cortisol into the bloodstream. The theory is that when people are under constant stress, the adrenal system reaches a burnout phase where the adrenals can’t keep up, thereby triggering a low cortisol level.

Low Cortisol could cause symptoms of low energy, depression, lightheadedness, and sleep issues. Although this is possible, there are many other factors and variables that can contribute to these types of symptoms.

But what you do if you have these types of symptoms?

Have a complete medical evaluation that looks at your comprehensive health and lifestyle. There are many reasons for these types of symptoms including hormone deficiency and imbalance; anemia, sleep disorders; stress; cardiovascular health; depression, anxiety, and kidney/liver function, just to name a few.

If you’ve got any concerns don’t hesitate to contact our medical staff and we’ll get back to you as soon as possible.