Low HGH Levels: What are the Symptoms?

Do You Have Symptoms of Low HGH Levels?

What improves your energy, helps you lose fat, increases muscle gain, makes bones more dense, makes skin look more youthful, improves sleep, improves memory, increases your capacity to exercise, and can reduce anxiety and depression?  If you said growth hormone, you’re right.  And, we didn’t even mention the word growth.  The benefits of growth hormone go way beyond its role in skeletal growth when we’re kids and adolescents. There are many symptoms related to low HGH levels.

Growth hormone (GH) is produced in the anterior pituitary gland that resides in the brain. Head trauma can lead to diminished growth hormone production.  Even a mild concussion can disrupt GH production.  See “Head Trauma Can Lead to Hormone Deficiencies”.

Many factors play a role in the production and release of growth hormone.  The signs and symptoms related to low HGH levels are multiple, but are also non-specific.  This mean that other causes could be responsible for the same signs and symptoms.  Therefore, it’s essential to be thoroughly evaluated by a physician knowledgeable in growth hormone if you suffer from many of the signs or symptoms listed below. Therapy for growth hormone deficiency is available and safe with few side effects when monitored closely by a physician.

Signs/Symptoms of Low HGH Levels

• Fatigue
• Metabolic syndrome
• Truncal obesity
• Decreased bone mineral density
• Decreased muscle strength and size
• Decreased energy and vitality
• Social withdrawal
• Depression/anxiety
• Increased cardiovascular risk
• Sleep disturbance
• Decreased cognitive ability
• Memory loss
• Reduced exercise capacity

What Stimulates Growth Hormone Release?

• Growth hormone releasing hormone (GHRH)
• Ghrelin
• Sex hormones (testosterone and estrogen)
• Low blood sugar (hypoglycemia)
• Arginine (amino acid)
• Propranolol (medication used to treat high blood pressure and heart disease)
• Deep sleep
• Fasting
• Vigorous exercise

What Inhibits Growth Hormone Release?

• High blood sugar
• Dihydrotestosterone
• Glucocorticoids (steroidal anti-inflammatory medication)

Diagnosing Adult Growth Hormone Deficiency (Low HGH Levels)

Diagnosing adult growth hormone deficiency or low HGH levels is not as easy as it may seem.  There is much controversy regarding the best way to diagnose adult growth hormone deficiency.  Certainly signs and symptoms should be taken into account and are very helpful.

The controversy is with what laboratory tests should be used.  It’s quite challenging to measure growth hormone levels in the blood.  Growth hormone is produced in pulses which can be quite random and related to many factors, though there is a predictable pulse during deep wave sleep.    Another problem is growth hormone has a short half-life of 20 to 30 minutes so it clears the blood quickly.  All of this makes interpreting growth hormones levels difficult.

Growth hormone, though, stimulates the liver to make insulin-growth factor 1 (IGF-1) which mediates many of the effects of growth hormone.   IGF-1 levels are fairly stable throughout the day.  Therefore, IGF-1 levels in adults is frequently performed first, though a normal levels does not exclude the possibility of someone having adult growth hormone deficiency.

Some experts argue that IGF-1 levels in conjunction with signs and symptoms is not enough to secure the diagnosis of adult growth hormone deficiency and suggest that the diagnosis can only be made from doing a stimulation test which measures one’s ability to release growth hormone in response to chemical stimulation.  There are several of these stimulation tests.  Some require hospitalization and there are some risks involved in performing them.

Many physicians still consider stimulation tests as the gold standard.  Stimulation tests, though, are far from reliable.  Some studies show that half of the patients that initially test negative on one stimulation test will test positive a week later on the same test.  Or, there can be conflicting results when two or more stimulation tests are performed on the same individual.

Interesting though, if someone is diagnosed with low HGH levels via a stimulation test, IGF-1 levels are then used to monitor treatment with human growth hormone replacement.  Stimulation tests cannot be used to monitor effectiveness of treatment.  So it seems somewhat contradictory that on one hand IGF-1 levels are not sufficient to make a diagnosis in the eyes of some, but acceptable to monitor one’s response to therapy.    Welcome to the inconsistencies in medicine.

See “Human Growth Hormone Facts” and “The Landmark Human Growth Hormone Study”.