Serum Insulin-Like Growth Factor-1 in Patients with De Novo, Drug Naïve Parkinson’s Disease: A Meta-Analysis

Abstract

ObjectiveInsulin-like growth factor-1 (IGF-1) is reported to be neuroprotective in the setting of Parkinson’s disease (PD), and there is increasing interest in the possible association of serum IGF-1 levels with PD patients, but with conflicting results. Therefore, we conducted a meta-analysis to evaluate the association of serum IGF-1 levels in de novo, drug naïve PD patients compared with healthy controls.MethodsPubmed, ISI Web of Science, OVID, EMBASE, and Cochrane library databases from 1966 to October 2014 were utilized to identify candidate studies using Medical Subjective Headings without language restriction. A random-effects model was chosen, with subgroup analysis and sensitivity analysis conducted to reveal underlying heterogeneity among the included studies.ResultsIn this meta-analysis, we found that PD patients had higher serum IGF-1 levels compared with healthy controls (summary mean difference [MD] = 17.75, 95%CI = 6.01, 29.48). Subgroup analysis demonstrated that the source of heterogeneity was population differences within the total group. Sensitivity analysis showed that the combined MD was consistent at any time omitting any one study.ConclusionsThe results of this meta-analysis demonstrate that serum IGF-1 levels were significantly higher in de novo, drug-naïve PD patients compared with healthy controls. Nevertheless, additional endeavors are required to further explore the association between serum IGF-1 levels and diagnosis, prognosis and early therapy for PD.

Is insulin-like growth factor-1 involved in Parkinson’s disease development?

“…These IGF-1 concentrations inversely correlate with the UPDRS-III score (i.e. with motor function), verbal episodic memory, visuoperceptual abilities and attention/ executive functions; been not found such correlation on healthy subjects [171][172][173][174][175][176][177][178][179][180][181]. As it has been shown, lower IGF-1 levels at the beginning of PD are associated with a worse disease progression and prognosis.…”

“…These data could act as a compensatory mechanism due to the lack of IGF-1 signaling feedback and, also, it could be an endogenous protective factor released in response to cell death and oxidative damage promoted by the disease itself. Such hypothesis is further sustained by a progressive PD model study where IGF-1 was found to protect the nigrostriatal pathway, and that this protection was preceded by activations of key pro-survival signaling cascades, such as Akt [181,196].…”

“…baseline, serum IGF-1 levels were significantly increased as compared to healthy controls A positive correlation between IGF-1 levels and a specific executive function (phonological fluency) assessing cognitive flexibility was found After a 2-year follow-up, IGF-1 levels were positively related to verbal episodic memory, visuoperceptual abilities and attention/executive functions Low IGF-1 levels at baseline were independently associated to poor performance on specific cognitive tasks assessing verbal episodic memory and executive functions after 2 baseline, serum IGF-1 levels were moderately increasedPatients at the highest IGF-1 quartile presented higher mean dopaminergic scores (worse outcome) were similar in PD and controls Lower serum IGF-1 levels were associated to poor performances in cognitive tasks assessing executive function, attention and verbal memory serum IGF-1 levels among de novo, drug-naïve idiopathic PD patients at baselineLi et al[181] HY Hoehn and Yahr score, MDS-UPDRS-III Movement Disease Society-modified UPDRS-III scale, SD standard deviation, UPDRS-III unified Parkinson's disease rating scale a Age, sex and body mass index (BMI, kg/m 2 ), as well as the presence or absence of other medical factors known to affect IGF-1 levels, termed medical confounders: diabetes mellitus (reported in medical history or inferred by antidiabetic medication intake), beta-adrenergic medication, depression (and/or antidepressant medication), neuroleptic medication, thyroid dysfunction, inflammatory diseases and cancer. All of them were taken into account when the study was carried outPage 10 of 17 Castilla-Cortázar et al J Transl Med (2020) 18:70…”

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

“…We also found a positive correlation of serum IGF‐1 with lower striatal SBR for DAT and the FAB scores in PD patients, suggesting that age‐related decreases in IGF‐1 levels may influence cognitive function in PD‐related disorders, interacting with the degeneration of nigrostriatal dopaminergic neurons. De novo and untreated patients with PD showed higher IGF‐1 levels than healthy controls, and serum IGF‐1 levels in PD patients negatively correlated with disease duration . Numao et al showed that MSA patients had higher serum IGF‐1 levels than controls, but there was no difference in serum IGF‐1 levels between PD patients and controls.…”

SERUM IGF-1& URIC ACID IN PATIENTS WITH PARKINSONS DISEASE AND PARKINSON PLUS SYNDROME.

“…They demonstrated high levels of serum IGF-1 in PD patients compared with controls. A meta-analysis by Li et al [24](166 PD patients and 323 healthy controls) demonstrated high levels of serum IGF-1 in PD patients compared with controls. Godau et al [7] conducted a study on 139 healthy controls and 15 PD patients found significant high serum IGF-1 in PD (P =0.004).…”