Department of Neurodegeneration, Hertie Institute for Clinical Brain Research (HIH), University of Tuebingen, Tuebingen, Germany.
Department of Pediatric Endocrinology, University Children`s Hospital Tuebingen, Tuebingen, Germany.
PLoS One. 2016 Mar 11;11(3):e0150552. doi: 10.1371/journal.pone.0150552. eCollection 2016.
Biomarkers indicating trait, progression and prediction of pathology and symptoms in Parkinson's disease (PD) often lack specificity or reliability. Investigating biomarker variance between individuals and over time and the effect of confounding factors is essential for the evaluation of biomarkers in PD, such as insulin-like growth factor 1 (IGF-1).
IGF-1 serum levels were investigated in up to 8 biannual visits in 37 PD patients and 22 healthy controls (HC) in the longitudinal MODEP study. IGF-1 baseline levels and annual changes in IGF-1 were compared between PD patients and HC while accounting for baseline disease duration (19 early stage: ≤3.5 years; 18 moderate stage: >4 years), age, sex, body mass index (BMI) and common medical factors putatively modulating IGF-1. In addition, associations of baseline IGF-1 with annual changes of motor, cognitive and depressive symptoms and medication dose were investigated.
PD patients in moderate (130±26 ng/mL; p = .004), but not early stages (115±19, p>.1), showed significantly increased baseline IGF-1 levels compared with HC (106±24 ng/mL; p = .017). Age had a significant negative correlation with IGF-1 levels in HC (r = -.47, p = .028) and no correlation in PD patients (r = -.06, p>.1). BMI was negatively correlated in the overall group (r = -.28, p = .034). The annual changes in IGF-1 did not differ significantly between groups and were not correlated with disease duration. Baseline IGF-1 levels were not associated with annual changes of clinical parameters.
Elevated IGF-1 in serum might differentiate between patients in moderate PD stages and HC. However, the value of serum IGF-1 as a trait-, progression- and prediction marker in PD is limited as IGF-1 showed large inter- and intraindividual variability and may be modulated by several confounders.
在帕金森病（PD）中，能够指示病理、进展和预测的生物标志物通常缺乏特异性或可靠性。研究个体间和随时间推移的生物标志物变化以及混杂因素的影响，对于评估 PD 中的生物标志物（如胰岛素样生长因子 1 [IGF-1]）至关重要。
在纵向 MODEP 研究中，我们对 37 名 PD 患者和 22 名健康对照者（HC）进行了多达 8 次的每半年 1 次的 IGF-1 血清水平检测。在考虑 PD 患者的基线疾病持续时间（19 例早期：≤3.5 年；18 例中期：>4 年）、年龄、性别、体重指数（BMI）和可能调节 IGF-1 的常见医学因素的情况下，比较了 PD 患者和 HC 之间的 IGF-1 基线水平和 IGF-1 的年度变化。此外，还研究了 IGF-1 基线水平与运动、认知和抑郁症状以及药物剂量的年度变化的相关性。
与 HC（106±24ng/mL;p=.017）相比，处于中期（130±26ng/mL;p=.004）但非早期阶段（115±19，p>.1）的 PD 患者的 IGF-1 基线水平显著升高。年龄与 HC 中 IGF-1 水平呈显著负相关（r=-.47，p=.028），而在 PD 患者中则无相关性（r=-.06，p>.1）。BMI 在总体人群中呈负相关（r=-.28，p=.034）。两组之间 IGF-1 的年度变化无显著差异，且与疾病持续时间无关。IGF-1 基线水平与临床参数的年度变化无关。
血清 IGF-1 水平升高可能有助于区分处于中度 PD 阶段的患者和 HC。然而，作为 PD 的特征、进展和预测标志物，血清 IGF-1 的价值有限，因为 IGF-1 显示出较大的个体间和个体内变异性，并且可能受到多种混杂因素的调节。
