Fig 1.
IGF-1 levels at baseline in healthy controls (HC), early-stage Parkinson's disease (E-PD) and moderate-stage PD (M-PD) adjusted for the effects of covariates age, sex, body mass index and the presence of medical confounders. Error bars indicate standard deviations. Group differences were tested using t-tests and a Bonforroni-corrected threshold of significance (three tests; p = .017). n.s. = non-significant; * p < .017.
Fig 2.
Linear annual change in IGF-1 levels of single individuals within groups of healthy controls (HC) and patients with Parkinson's disease in early (E-PD) or moderate (M-PD) disease stages. High inter-individual differences, with increasing (+) and decreasing (-) IGF-1 levels over time, were observed. Differences between groups were not significant (n.s.) as tested using t-tests.
Fig 3.
IGF-1 as a predictor of changes in clinical parameters.
PD patient groups with low and high IGF-1 baseline levels (median split at 122 ng/mL). Groups show no significant differences (p > .1) in annual changes of (a) PD-motor symptom severity (UPDRS-III), (b) PD-medication (L-dopa equivalent dose, LED), (c) depressive symptoms (BDI score) and (d) global cognitive function (MMSE score).