BackgroundLinear associations between circulating insulin-like growth factor-1 (IGF-1) levels and Parkinson’s disease (PD) have been evidenced in observational studies. Yet, the causal relationship between IGF-1 levels and PD remains obscure. We conducted Mendelian randomization to examine the correlation between genetically predicted IGF-1 levels and PD.MethodsBy reviewing genome-wide association studies (GWAS) that are publicly accessible, we uncovered SNPs linked to both serum concentrations of IGF-1 and PD. A two-sample Mendelian randomization (MR) analysis was carried out to evaluate the individual effect of IGF-1 on PD.ResultsIn a primary causal effects model in MR analysis, employing the inverse-variance weighted (IVW) method, IGF-1 levels exhibited a notable association with the risk of PD (OR, 1.020, 95% CI, 1.003–1.038, p = 0.0215). Multiple evaluations revealed that horizontal pleiotropy was improbable to distort the main results (MR-Egger: P PD intercept =0.719), and no bias was detected by leave-one-out analysis.ConclusionThis study unearthed evidence indicating that heightened IGF-1 levels might be causally correlated with an increased risk of PD.

中文翻译：

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循环胰岛素样生长因子-1 与帕金森病之间的因果关系：双样本孟德尔随机化研究

背景观察性研究已证明循环胰岛素样生长因子-1 (IGF-1) 水平与帕金森病 (PD) 之间存在线性关联。然而，IGF-1 水平与 PD 之间的因果关系仍不清楚。我们进行了孟德尔随机化，以检查基因预测的 IGF-1 水平与 PD 之间的相关性。方法通过回顾公开的全基因组关联研究 (GWAS)，我们发现了与 IGF-1 和 PD 血清浓度相关的 SNP。进行两样本孟德尔随机化 (MR) 分析，以评估 IGF-1 对 PD 的个体影响。结果 在 MR 分析的主要因果效应模型中，采用逆方差加权 (IVW) 方法，IGF-1 水平与 PD 风险显着相关（OR，1.020，95% CI，1.003–1.038，p= 0.0215）。多项评估表明，水平多效性不太可能扭曲主要结果（MR-Egger：P PD 截距=0.719），并且留一分析未检测到偏差。结论本研究发现的证据表明，IGF-1 水平升高可能会导致与 PD 风险增加存在因果关系。