| Affiliation: | 1. Department of Biochemistry, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil;2. Postgraduate Program in Medical Sciences, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil;3. Neurology Service, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, RS, Brazil;4. Medical Genetics Service, Hospital de Clínicas de Porto Alegre (HCPA), Porto Alegre, RS, Brazil;5. Neuroradiology Service, Hospital Moinhos de Vento, Porto Alegre, Brazil;6. Neurology Service, Hospital Universitario “La Paz” (HULP), Madrid, Spain;7. Laboratory of Cellular and Molecular Neuroendocrinology, Instituto Cajal, Consejo Superior de Investigaciones Cientificas (CSIC), Madrid, Spain;8. CIBERNED, Madrid, Spain;9. Department of Internal Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil |
| Abstract: | Spinocerebellar ataxias (SCAs) constitute a group of autosomal dominant neurodegenerative disorders with no current treatment. The insulin/insulin‐like growth factor 1 (IGF‐1) system (IIS) has been shown to play a role in the neurological dysfunction of SCAs and other polyglutamine disorders. We aimed to study the biomarker profile of serum IIS components in SCA3. We performed a case–control study with 46 SCA3 patients and 42 healthy individuals evaluating the peripheral IIS profile (insulin, IGF‐1, IGFBP1 and 3) and the correlation with clinical, molecular, and neuroimaging findings. SCA3 patients presented lower insulin and IGFBP3 levels and higher insulin sensitivity (HOMA2), free IGF‐I, and IGFBP1 levels when compared with controls. IGFBP‐1 levels were directly associated with CAG expanded repeat length; IGF‐1 was associated with the volumetries of specific brainstem regions on magnetic resonance imaging (MRI). Insulin levels and sensitivity were related to age at onset of symptoms. Our findings indicate an involvement of IIS components in SCA3 neurobiology and IGFBP‐1 as a potential biomarker of the disease. © 2010 Movement Disorder Society |
