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

Background: We investigated serum insulin‐like growth factor (IGF)‐1 levels in patients with neurodegenerative diseases and correlated these levels with clinical parameters. Methods: One hundred and fifty‐six patients with neurodegenerative diseases were included in this study, and serum IGF‐1 levels were determined. Results: 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 ± 5.1 ng/mL; progressive supranuclear palsy (n = 15), 102.9 ± 8.3 ng/mL; multiple system atrophy (n = 22), 103.1 ± 37.6 ng/mL; Alzheimer's disease (AD; n = 18), 102.2 ± 9.4 ng/mL; amyotrophic lateral sclerosis (n = 6), 105.5 ± 27.4 ng/mL; dementia with Lewy bodies (n = 14), 82.4 ± 7.4 ng/mL; frontotemporal dementia (n = 6), 90.0 ± 17.0 ng/mL; and corticobasal syndrome (n = 2), 118.0 ± 14.0 ng/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. Conclusion: 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. [ABSTRACT FROM AUTHOR]