Introduction: Functional GH deficiency has been described in fibromyalgia (FM). The efficacy of GH as add-on treatment has been suggested in small studies, but little is known in larger and homogeneous populations.
Design: Patients (120) were enrolled in a multicenter, randomized, placebo-controlled trial for 18 months (NCT00933686). FM impact questionnaire (FIQ) >75 (severe), duration of FM >18 months, and stability of the standard therapy (amitriptiline+opioids+SSRI) >12 months were required. Adult GH deficiency and insensitivity were ruled out with an ITT test and IGF1-generation test respectively. In the first 6 months (blind-phase), Group A received 0.006 mg/kg per day of GH s.c. (further titrated based on IGF1) and group B, placebo, both added to standard therapy. Placebo arm was then switched to GH from 6 to 12 months (open-phase), and an extension study from 12 to 18 months was carried-on after GH withdrawal. Number and intensity of tender points, FIQ and subscales, Quality of Life test (EQ5D) with visual analogic scale (VAS) were evaluated at different time-points.
Results: At 12 months, 53% of the patients in group A (GH continuously) reached <11 positive tender points (cut-off for diagnosis) versus 33% in group B (6 months of GH) (P<0.05). Significant improvements were also seen comparing FIQ (P=0.01), subscales (P<0.05) and EQ5D (P<0.05). In group A, 56.5% patients reached >30% improvement in VAS and 39.1%>50%. Medication withdrawal in the extension study phase worsened all the scores within each group from the 1st month of follow-up (P<0.05). Carpal tunnel syndrome was the most prevalent related adverse event (17%) and no discontinuations were seen.
Conclusions: This is the larger and longer placebo-controlled trial performed so far in FM. Added GH is comparable to some labelled drugs in term of pain reduction, FIQ and VAS and further shows a sustained pattern of action.
30 Apr - 04 May 2011
European Society of Endocrinology