There are evidences of functional growth hormone (GH) deficiency, expressed by means of low serum levels of insulin-like growth factor 1 (IGF-1), in a subset of fibromyalgia patients. The efficacy of low GH doses versus placebo has been demonstrated in this population. We assessed the efficacy and safety of GH added to standard therapy compared to standard therapy alone in the treatment of severe, prolonged and well-treated fibromialgya patients with low IGF-1 levels.

Inclusion Criteria:

• Women greater than 18 years old with severe fibromyalgia and abnormally low IGF-1 levels included in a rehabilitation and psychological program and stable under standard intensive treatment for at least 6 months.
• All patients fulfilled the 1990 ACR diagnostic criteria (1) and had an IGF-1 level <250 ng/mL (or 1 standard deviation bellow the mean value corresponding to age and body surface according to laboratory reference value).
• Other inclusion criteria were duration of fibromyalgia of 1 year or greater, pain in at least 16 (8 bilateral) of the 18 tender points and a score in the FIQ > 75.
• The study was conducted in accordance with the Declaration of Helsinki and received the local institutional review board and Spanish Drug Agency (nº03-0456) approvals. All patients gave written informed consent prior to their inclusion in the study.

Exclusion Criteria:

• Disabling physical or mental status
• Previous or current malignancies, either active or inactive
• Intracranial space occupying lesion
• Any relevant endocrine disorder including diabetes mellitus
• History of another pituitary disorder
• Previous treatment with growth hormone
• Other systemic or joint inflammatory rheumatic conditions; and
• Known to be hypersensitive to somatropin or any of the excipients.
• Pregnant women, nursing mothers, or women with childbearing potential not using adequate contraceptive methods were also excluded.