Growth hormone (GH) is an important compound produced by the pituitary gland that stimulates the growth of muscles and bones, and helps regulate the body’s metabolism. While the amount of growth hormone in the blood changes throughout the course of a day, recent research has demonstrated similarities between unusually low GH levels and the symptoms of fibromyalgia (FM).
According to renowned Chronic Fatigue Syndrome (CFS) physician and researcher, Paul Cheney, M.D., the key function of growth hormone is protein synthesis. It sharply increases the flow of sugar into muscle and fat, stimulates protein production in the liver and muscle, and slows the production of fatty tissue. Along with cortisol, growth hormone helps maintain blood sugar levels in the brain, and increases the availability of fat to other body cells as fuel.
Growth hormone is replenished during the sleep cycle, particularly during stage four deep sleep. For fibromyalgia patients, approximately 60-90% report trouble sleeping (some reports suggest that as many as 100% of patients have un-refreshing sleep.) Likewise, David Bell, M.D., reports that “…Sleep disturbance is present in almost all [CFS] patients.” Growth hormone is almost entirely produced during delta-wave present deep sleep. Stated simply, if you are not sleeping deeply, you are probably not producing adequate levels of growth hormone.
Research on Growth Hormone and FM
In a study led by Robert Bennett, M.D., Ph.D. from the Oregon Health Sciences University (OHSU), 70 female FM patients and 55 healthy controls were evaluated to see if the stage four sleep disruption seen in the FM patients affected growth hormone secretion1.
Growth hormone has a very short half-life and can break down over a brief period of time. In the study, the researchers measured serum levels of a compound called somatomedin C. This compound is the major regulator of growth hormone’s actions and is required to maintain normal muscle health. The results showed significantly lower levels of somatomedin C in the fibromyalgia patients compared with controls. These results could not be explained by an accompanying therapy or by weight, and in a subset of 21 patients in whom this was investigated, there was no correlation with various indicators of disease activity.
These findings indicate that there is a distinctive disruption of the growth hormone somatomedin C in a majority of fibromyalgia patients, and that this abnormality may explain the link between disturbed sleep and predisposition to muscle pain.
Another indicator of growth hormone levels in the body is insulin-like growth factor 1 (IGF-1). As growth hormone circulates in the blood stream it stimulates the liver to produce IGF-1. This is a marker for growth hormone production. Low levels of IGF-1 have been found in fibromyalgia patients demonstrating symptoms such as low energy, impaired cognition, and muscle weakness.
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In a 1998 study, Dr. Bennett and fellow OHSU researchers conducted a double-blind, placebo-controlled study to determine if suboptimal growth hormone production was relevant to the symptoms of fibromyalgia, and assessed the clinical effects of growth hormone treatment upon related symptoms2.
Fifty women diagnosed with fibromyalgia entered into a nine month study. Daily subcutaneous injections of growth hormone or placebo were administered to the patients. The results showed daily growth hormone injections produced a prompt and sustained increase in IGF-1 levels. The treatment group showed significant improvements over placebo in both the Fibromyalgia Impact Questionnaire (FIQ) and tender point scores after nine months. The researchers noted a delayed response to therapy, with most patients seeing improvements at the six month mark.
The researchers also found after treatment was discontinued, subjects reported a worsening of symptoms one to three months after treatment.
The researchers concluded that a secondary growth hormone deficiency may be responsible for some FM symptoms, while daily growth hormone therapy improved overall symptomatology and number of tender points.
Options for Growth Hormone Deficient Individuals
Growth Hormone injections are very expensive, with year long treatments ranging from $12,000 to $20,000. As a result, other growth hormone enhancing methods have emerged. Some options include secretagogues that contain amino acids to stimulate the pituitary gland to produce GH naturally, or supplementation of the IGF-1 protein directly into the body.
1. Bennett RM, Clark SR, Campbell SM, Burckhardt CS. “Low levels of somatomedin C in patients with the fibromyalgia syndrome. A possible link between sleep and muscle pain.” Arthritis Rheum. 1992 Oct; 35(10):1113-6.
2. Source: Bennett R.M., Clark S.C., Walczyk J. “A randomized, double-blind, placebo-controlled study of growth hormone in the treatment of fibromyalgia.” American Journal of Medicine 1998 Mar; 104 (3): 227-231.