Twins Research Australia, Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health, The University of Melbourne, Melbourne, Victoria, Australia.
Twin Res Hum Genet. 2020 Dec;23(6):322-329. doi: 10.1017/thg.2020.86. Epub 2021 Jan 29.
There is a commonly observed association between chronic disease and psychological distress, but many potential factors could confound this association. This study investigated the association using a powerful twin study design that can control for unmeasured confounders that are shared between twins, including genetic and environmental factors. We used twin-paired cross-sectional data from the Adult Health and Lifestyle Questionnaire collected by Twins Research Australia from 2014 to 2017. Linear regression models fitted using maximum likelihood estimations (MLE) were used to test the association between self-reported chronic disease status and psychological distress, measured by the Kessler Psychological Distress Scale (K6). When comparing between twin pairs, having any chronic disease was associated with a 1.29 increase in K6 (95% CI: 0.91, 1.66; p < .001). When comparing twins within a pair, having any chronic disease was associated with a 0.36 increase in K6 (95% CI: 0.002, 0.71; p = .049). This within-pair estimate is of most interest as comparing twins within a pair naturally controls for shared factors such as genes, age and shared lived experiences. Whereas the between-pair estimate does not. The weaker effect found within pairs tells us that genetic and environmental factors shared between twins confounds the relationship between chronic disease and psychological distress. This suggests that associations found in unrelated samples may show exaggerated estimates.
慢性疾病和心理困扰之间存在着一种常见的关联，但许多潜在的因素可能会混淆这种关联。本研究使用强大的双胞胎研究设计来研究这种关联，这种设计可以控制双胞胎之间共享的未测量混杂因素，包括遗传和环境因素。我们使用了澳大利亚双胞胎研究中心在 2014 年至 2017 年期间从成人健康和生活方式问卷调查中收集的双胞胎配对横断面数据。使用最大似然估计（MLE）拟合的线性回归模型来测试自我报告的慢性疾病状况与心理困扰之间的关联，心理困扰用 Kessler 心理困扰量表（K6）来衡量。在比较双胞胎对时，患有任何慢性疾病与 K6 增加 1.29 有关（95%CI：0.91，1.66；p<.001）。在比较双胞胎对中的双胞胎时，患有任何慢性疾病与 K6 增加 0.36 有关（95%CI：0.002，0.71；p=.049）。这种对双胞胎内部的估计是最有趣的，因为比较双胞胎对中的双胞胎自然控制了基因、年龄和共同生活经历等共享因素。而对双胞胎间的估计则不然。在双胞胎内部发现的较弱效应告诉我们，双胞胎之间共享的遗传和环境因素混淆了慢性疾病和心理困扰之间的关系。这表明在无关样本中发现的关联可能显示出夸大的估计。
