UNASSIGNED: Instrumental variables (IVs) for exposures and outcome were obtained from the largest publicly available genome-wide association studies (GWAS) databases. First, we performed a bidirectional univariate MR analysis using primarily the inverse variance weighted method (IVW) with height, screen time, physical activity and sleep as the exposure and myopia as the outcome to investigate the causal relationship between exposures and myopia. Sensitivity analysis was used to demonstrate its robustness. Then the multivariable MR (MVMR) and MR-based mediation approach was further used to estimate the mediating effect of potential confounders (education and time outdoors) on causality.
UNASSIGNED: The results of univariate MR analysis showed that taller height (OR = 1.009, 95% CI = 1.005-1.012, p = 3.71 × 10-7), longer time on computer (OR = 1.048, 95% CI = 1.029-1.047, p = 3.87 × 10-7) and less moderate physical activity (OR = 0.976, 95% CI = 0.96-0.991 p = 2.37 × 10-3) had a total effect on the increased risk of developing myopia. Meanwhile our results did not have sufficient evidence to support the causal relationship between chronotype (p = 0.637), sleep duration (p = 0.952) and myopia. After adjusting for education, only taller height remains an independent risk factor for myopia. After adjusting for education, the causal relationship between height, screen and myopia still had statistical significance. A reverse causal relationship was not found in our study. Most of the sensitivity analyses showed consistent results with those of the IVW method.
UNASSIGNED: Our MR study revealed that genetically predicted taller height, longer time on computer, less moderate physical activity increased the risk of myopia. After full adjustment for confounders, only height remained independently associated with myopia. As a complement to observational studies, the results of our analysis provide strong evidence for the improvement of myopia risk factors and provide a theoretical basis for future measures to prevent and control myopia in adolescents.
■用于暴露和结果的工具变量(IVs)来自最大的公开全基因组关联研究(GWAS)数据库。首先,我们主要使用逆方差加权法(IVW)与高度进行双向单变量MR分析,屏幕时间,以身体活动和睡眠为暴露和近视为结果,探讨暴露与近视之间的因果关系。敏感性分析用于证明其稳健性。然后进一步使用多变量MR(MVMR)和基于MR的中介方法来估计潜在混杂因素(教育和户外时间)对因果关系的中介作用。
■单变量MR分析结果表明,较高的身高(OR=1.009,95%CI=1.005-1.012,p=3.71×10-7),使用计算机的时间更长(OR=1.048,95%CI=1.029-1.047,p=3.87×10-7)和较少的适度体育锻炼(OR=0.976,95%CI=0.96-0.991p=2.37×10-3)对近视的风险增加具有总体影响。同时,我们的结果没有足够的证据支持时间型之间的因果关系(p=0.637),睡眠时间(p=0.952)和近视。在适应教育之后,只有身高较高仍然是近视的独立危险因素。在适应教育之后,身高之间的因果关系,视力和近视仍有统计学意义。在我们的研究中没有发现反向因果关系。大多数灵敏度分析显示与IVW方法的结果一致。
■我们的MR研究表明,基因预测身高更高,在电脑上的时间更长,适度的体力活动会增加近视的风险。在对混杂因素进行全面调整后,只有身高与近视独立相关.作为观察性研究的补充,我们的分析结果为近视危险因素的改善提供了有力的证据,为今后预防和控制青少年近视的措施提供了理论依据。