[Note: Insulin-like growth factor 1 (growth hormone) helps maintain muscle tissue. Most growth hormones are secreted during the deep sleep cycle, so it is important to reach this restorative sleep phase for healthy levels of IGF-1. Recent research indicating sodium oxybate (Xyrem) may help fibromyalgia symptoms could be owing to an ability to stimulate release of growth hormone. See for example “Sodium oxybate for the treatment of fibromyalgia,” Jun 16, 2011, by Roland Staud at the University of Florida.]
Functional defects in growth hormone (GH) secretion and its efficacy as a complementary treatment have been suggested for fibromyalgia.
This study investigated the efficacy and safety of low-dose GH as an add-on therapy in patients with both severe FM and low insulin-like growth factor 1 levels.
A total of 120 patients were enrolled in a multicenter, placebo-controlled study for 18 months.
• They were randomly assigned to receive either 0.006mg/kg/day of GH subcutaneously (group A, n=60) or placebo (group B, n=60) for 6 months (blind phase).
• The placebo arm was switched to GH treatment from month 6 to month 12 (open phase),
• And a follow-up period after GH discontinuation was performed until month 18.
Standard treatment for fibromyalgia (selective serotonin re-uptake inhibitors, opioids, and amitriptyline) was maintained throughout the study.
Number and intensity of tender points, Fibromyalgia Impact Questionnaire (FIQ) with its subscales, and EuroQol 5 dimensions test (EQ5D) with visual analog [pain] scale (VAS) were assessed at different time points. At the end of the study [6 months after therapy ended]:
• 53% of group A patients [who received GH for 12 months] obtained fewer than 11 positive tender points, vs 33% of group B patients [who received GH from months 7 -12] (P<.05).
• 39.1% vs 22.4% reached more than 50% improvement in VAS (P<.05). [The VAS pain scale measures pain by color, descriptions, and numbers 1-10, from 'none' (0) to 'agonizing' (10).]
• Group A patients showed significantly improved FIQ scores (P=.01) compared with group B.
Although GH discontinuation worsened all scores in both groups during follow-up, impairment in pain perception was less pronounced in the GH-treated group [who received it for 12 months](P=.05).
In this largest and longest placebo-controlled trial performed in FM (NCT00933686), addition of GH to the standard treatment is effective in reducing pain, showing sustained action over time.
Source: Pain, Mar 30, 2012. Cuatrecasas G, Alegre C, Fernandez-Solà J, Gonzalez MJ, Garcia-Fructuoso F, Poca-Dias V, Nadal A, Cuatrecasas G, Navarro F, Mera A, Lage M, Peinó R, Casanueva F, Liñan C, Sesmilo G, Coves MJ, Izquierdo JP, Alvarez I, Granados E, Puig-Domingo M. Endocrinology Department Centro Médico Teknon and Clinica Sagrada Familia, Barcelona, Spain.