Affiliated Hospital of Qingdao University & Biomedical Sciences Institute of Qingdao University, Qingdao University; and Shanghai Clinical Research Centre for Mental Health, Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Centre, Shanghai Jiao Tong University School of Medicine; and Bio-X Institutes, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders (Ministry of Education), Collaborative Innovation Centre for Brain Science, Shanghai Jiao Tong University, P. R. China; and Department of Psychological Medicine, Institute of Psychiatry, Psychology and Neuroscience, King's College London, UK.
Affiliated Hospital of Qingdao University & Biomedical Sciences Institute of Qingdao University, Qingdao University, P. R. China.
Br J Psychiatry. 2021 Feb;218(2):98-103. doi: 10.1192/bjp.2020.116.
The link between schizophrenia and cigarette smoking has been well established through observational studies. However, the cause-effect relationship remains unclear.
We conducted Mendelian randomisation analyses to assess any causal relationship between genetic variants related to four smoking-related traits and the risk of schizophrenia.
We performed a two-sample Mendelian randomisation using summary statistics from genome-wide association studies (GWAS) of smoking-related traits and schizophrenia (7711 cases, 18 327 controls) in East Asian populations. Single nucleotide polymorphisms (SNPs) correlated with smoking behaviours (smoking initiation, smoking cessation, age at smoking initiation and quantity of smoking) were investigated in relation to schizophrenia using the inverse-variance weighted (IVW) method. Further sensitivity analyses, including Mendelian randomisation-Egger (MR-Egger), weighted median estimates and leave-one-out analysis, were used to test the consistency of the results.
The associated SNPs for the four smoking behaviours were not significantly associated with schizophrenia status. Pleiotropy did not inappropriately affect the results.
Cigarette smoking is a complex behaviour in people with schizophrenia. Understanding factors underlying the observed association remains important; however, our findings do not support a causal role of smoking in influencing risk of schizophrenia.
通过观察性研究已经充分证实了精神分裂症与吸烟之间的联系。然而，因果关系仍不清楚。
我们进行了孟德尔随机化分析，以评估与四种与吸烟相关的特征相关的遗传变异与精神分裂症风险之间是否存在因果关系。
我们使用东亚人群中与吸烟相关特征和精神分裂症（7711 例病例，18327 例对照）的全基因组关联研究（GWAS）的汇总统计数据，进行了两样本孟德尔随机化分析。使用逆方差加权（IVW）方法，研究与吸烟行为（吸烟起始、戒烟、吸烟起始年龄和吸烟量）相关的单核苷酸多态性（SNP）与精神分裂症的关系。进一步的敏感性分析，包括孟德尔随机化- Egger（MR-Egger）、加权中位数估计和逐一剔除分析，用于测试结果的一致性。
四种吸烟行为的相关 SNP 与精神分裂症状态无显著相关性。多效性并未不适当地影响结果。
精神分裂症患者的吸烟是一种复杂的行为。了解观察到的关联背后的因素仍然很重要；然而，我们的研究结果并不支持吸烟在影响精神分裂症风险方面的因果作用。
