Serum insulin-like growth factor-1 levels in neurodegenerative diseases.

Abstract

We investigated serum insulin-like growth factor (IGF)-1 levels in patients with neurodegenerative diseases and correlated these levels with clinical parameters. One hundred and fifty-six patients with neurodegenerative diseases were included in this study, and serum IGF-1 levels were determined. Serum IGF-1 levels (mean±standard error) were not significantly different among the patients with different neurodegenerative diseases: Parkinson's disease (PD; n=73), 112.1±5.1ng/mL; progressive supranuclear palsy (n=15), 102.9±8.3ng/mL; multiple system atrophy (n=22), 103.1±37.6ng/mL; Alzheimer's disease (AD; n=18), 102.2±9.4ng/mL; amyotrophic lateral sclerosis (n=6), 105.5±27.4ng/mL; dementia with Lewy bodies (n=14), 82.4±7.4ng/mL; frontotemporal dementia (n=6), 90.0±17.0ng/mL; and corticobasal syndrome (n=2), 118.0±14.0ng/mL. In patients with PD, serum IGF-1 levels were negatively correlated with age and modified Rankin scale (mRS) scores and positively correlated with the striatal dopamine transporter-specific binding ratio and the frontal assessment battery score. In patients with AD, serum IGF-1 levels were negatively correlated with age, disease duration, and mRS scores. We found correlations of serum IGF-1 levels with frontal lobe and striatal dopaminergic function and disability in PD patients and with disability in AD patients. The usefulness of measuring serum IGF-1 levels for monitoring disease progression in neurodegenerative diseases requires further studies.