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6 Articles in this Series
Introduction
Where Are We With a National Pain Strategy?
Prevalence of Growth Hormone Deficiency in Fibromyalgia
The Perfect Storm: Chronic Pain, Inflammation, and Dysfunctional Sleep
Ketamine and Pyschotherapy Effective for Management of CRPS and PTSD
Using a Multimodal Approach to Physical Therapy for Chronic Pain
Combining Noninvasive Brain Stimulation Therapies for CRPS

Prevalence of Growth Hormone Deficiency in Fibromyalgia

Physicians should explore easily detectable and treatable hGH levels in their FM patients.

Interview with Thomas J. Romano MD, PhD, FACP, FACR, DAAPM

Doctors usually consider human growth hormone (hGH) as a promoter of linear growth in children. In reality, hGH’s physiologic importance is far-reaching, and could be an overlooked factor in the broad population of adults with fibromyalgia syndrome (FM).

Most doctors do not consider their patients’ hGH levels when managing symptoms of fibromyalgia, challenged Thomas J. Romano, MD, PhD, FACP, FACR, DAAPM, a rheumatologist based in Martins Ferry, Ohio.1 Yet this could be a significant oversight, according to new research indicating that an overwhelming percentage of FM patients have low hGH levels, requiring replacement therapy.1

“The problem is that in the old days, endocrinologists were taught that hGH deficiency in adults was usually the result of a pituitary tumor since the hormone is produced by the anterior pituitary gland,” or that hGH deficiency had to be caused by some form of massive head trauma, Dr. Romano told Practical Pain Management (PPM).

The reality is that hGH deficiency may be found in about 1/3 of all fibromyalgia patients,2 which may be 1 of the most prevalent factors affecting inadequate patient outcomes for those taking medications to manage their FM.

Growth Hormone: Overlooked in FM Management?

“Fibromyalgia patients are difficult to treat for a large number of reasons,” said Dr. Romano, "and a major reason is their propensity to have multiple comorbidities, including low thyroid hormone, low magnesium levels, and low hGH."

A prime stimulator of protein synthesis and cellular uptake of amino acids, hGH is known to play a role in various physiological processes. Therefore, an hGH deficiency has been linked to a variety of health issues, including increased fatigue, atypical depression, chronic pain, impaired cognition—many of the symptoms synonymous with the complaints expressed by FM patients.3

Currently, there are 3 drugs approved by the US Food and Drug Administration (FDA) for the treatment of fibromyalgia, including:

  • Pregabalin (Lyrica; Pfizer Inc.)
  • Duloxetine (Cymbalta; Eli Lilly & Company)
  • Milnacipran (Savella; Allergan)

Unfortunately, FM can be a difficult condition to treat even with the help of these medications. Patients often gain weight as a side effect of antidepressants and still experience chronic pain, sleep disturbance, and other symptoms that adversely affect their quality of life, Dr. Romano noted.

FM patients should have their serum levels for hGH checked, but unfortunately, this is not standard practice for practitioners who treat patients with FM. While serum level charts do provide doctors with a normal range for hGH levels, some clinicians may not be aware that hGH levels are age-dependent.“The normal range is not very helpful because it gives a number for what’s normal for the general population at all ages, so it’s a very broad range,” he noted. A simple formula can be used to determine the age-dependent range for hGH levels.

At his own private practice, Dr. Romano tested serum levels of hGH in 78 female FM patients (mean age, 45 years) treated over the past 4 years. Dr. Romano found 70 patients (90%) had low-for-age insulin-dependent growth factor 1 (IGF-1), a hormone that secretes in response to hGH. Of those 70 patients, 48 patients (68.5%) received an IV growth hormone stimulation test. Dr. Romano found 44 patients (92%) subsequently failed the test, confirming diagnosis of growth hormone deficiency (GHD). This meas that out of the 78 patients, at least 56% had GHD.1 The percentage possibly could have been higher, considering 22 patients were unable to receive the stimulation test because of insurance reasons, Dr. Romano noted.

The research is not the first investigation into GHD in FM patients. Since the early 1990s, researchers have hypothesized GHD to be intrinsically linked to FM, considering patients with FM have a tendency to suffer from an abnormal sleep pattern that affects the 3rd and 4th stages of non-REM sleep.4 Interestingly, growth hormone reaches its peak rate of secretion during those stages of rest.5

Treating GHD in FM Patients

“Fibromyalgia treatment won’t really succeed very well if you don’t acknowledge the comorbidities because you can’t cure fibromyalgia, but you can sure treat and reverse problems like hGH deficiency,” Dr. Romano told PPM.

Indeed, once patients are confirmed to have a deficiency in the hormone, replacement therapy yields consistently positive results. While it can take up to 6 months for patients to notice an effect, significant improvements in Fibromyalgia Impact Questionnaire Scores and tender point scores have been documented.6

Patients also report general increases in energy, improvements in mood, and a higher propensity for exercise and better muscle strength about 3 months into treatment.6-8

When the treatment is properly titrated to an effective dose, adverse reactions are very rare for patients, especially if patients show no contraindications prior to taking the drug, such as the presence of a tumor or a prior abdominal surgery. According to Dr. Romano, about 5% of patients may experience myalgia, or severe muscle pains, which may necessitate the patient is taking off the therapy. However, this occurs in patients within the first few weeks of treatment and never becomes an issue for patients already taking the drug for a long period of time.

Other patients may experience an increase in blood sugar. However, those patients also show an increased energy inventory for exercise and general activity. In those cases, patients who exercise regularly see their blood sugar levels naturally drop, as well as reap the rewards of fat loss and increased lean muscle mass, Dr. Romano noted.

According to Dr. Romano, it’s important for practitioners to be aware of the prevalence of GHD in the general FM population, and he encourages practitioners to test their patients’ growth hormone levels to help determine if there is a need for replacement therapy. It also should be noted that other related syndromes have been associated with GHD. “I’m not just finding it in fibromyalgia patients, I’m finding it in a bunch of people who have chronic pain problems that are interrelated with sleep.”

References

  1. Romano TJ. Prevalence of growth hormone deficiency in fibromyalgia.  Abstract presented at: Academy of Integrative Pain Management 27th Annual Meeting; September 23, 2016; San Antonio, Texas.
  2. Bennett RM, Clark SR, Campbell SM, at al. Low levels of somatomedin C in patients with the fibromyalgia syndrome. A possible link between sleep and muscle pain. Arthritis Rheum. 1992;35:1113-1116.
  3. Jones KD, Deodhar P, Lorentzen A, et al. Growth hormone perturbations in fibromyalgia: a review. Semin Arthritis Rheum. 2007;36:357-379.
  4. Moldofsky H, Scarisbrick P, England R, et al. Musculoskeletal symptoms and non-REM sleep disturbance in patients with "fibrositis syndrome" and healthy subjects. Psychosom Med. 1975;37:341-351.
  5. Bennett RM. Beyond fibromyalgia: ideas on etiology and treatment. J Rheumatol. 1989;19(suppl):185-191.
  6. Bennett RM, Clark SC, Walczyk J. A randomized, double-blind, placebo-controlled study of growth hormone in the treatment of fibromyalgia. The American Journal of Medicine. 1998;104:227-231.
  7. Cuneo RC, Salomon F, Wiles CM, et al. Growth hormone treatment in growth hormone-deficient adults. II. Effects on exercise performance. J Appl Physiol. 1991;70:695-700.
  8. Cuneo RC, Salomon F, Wiles CM, et al. Growth hormone treatment in growth hormone-deficient adults. I. Effects on muscle mass and strength. J Appl Physiol. 1991;70:688-694.
Next summary: The Perfect Storm: Chronic Pain, Inflammation, and Dysfunctional Sleep
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