title: Role of insulin-like growth factor-I in the treatment of painful small fiber predominant neuropathy.
abstract: Idiopathic, painful, small fiber predominant peripheral neuropathy is resistant to symptomatic treatment. Previous treatments have not been directed toward repairing the underlying deficit. Growth factors hold promise as agents to encourage axonal regrowth. In vitro, insulin-like growth factor-I (IGF-I) has been shown to prevent neuronal apoptosis, to increase axonal growth, and to support myelination. Using a double-blind, placebo-controlled design, 40 patients were randomized to treatment with recombinant human IGF-I (0.05 mg/kg twice daily by subcutaneous injection) or placebo for 6 months. There were no significant adverse events and minor adverse events occurred equally in both groups. The primary outcome measure was change in score on an analog pain scale. Secondary endpoints included quantitative sensory testing, quantitative autonomic testing, neuropathy impairment score, nerve conduction studies, and neuropathy symptom and change score. There was no significant difference in the primary endpoint between the two groups. Analysis of secondary endpoints and a global impression of improvement by patients and physicians did not show consistent differences between the groups. IGF-I was safe, but did not improve symptoms in this 6-month trial.
authors.affiliation: Department of Neurology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA. windebank.anthony@mayo.edu
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Windebank
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Sorenson
authors.forename: Richard
authors.initials: R
authors.lastname: Civil
authors.forename: Peter C
authors.initials: PC
authors.lastname: O'Brien
mesh_terms: D000328:Adult; D000368:Aged; D004311:Double-Blind Method; D004569:Electroencephalography / Q000187:drug effects / Q000379:methods; D005260:Female; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000187:drug effects; D009437:Neuralgia / Q000188:drug therapy* / Q000209:etiology; D010147:Pain Measurement / Q000187:drug effects / Q000379:methods; D010523:Peripheral Nervous System Diseases / Q000150:complications / Q000188:drug therapy*; D011994:Recombinant Proteins / Q000627:therapeutic use; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D011994:Recombinant Proteins; D007334:Insulin-Like Growth Factor I