From the University of Sydney (Pinheiro, Refshauge, Ferreira), Faculty of Health Sciences, Australia; University of Murcia (Morosoli, Madrid-Valero, Ordoñana) Department of Human Anatomy and Psychobiology, and Murcia Institute of BioHealth Research (IMIB-Arrixaca-UMU), Spain; Department of Genetics and Computational Biology (Morosoli), QIMR Berghofer Medical Research Institute; School of Psychology (Morosoli), The University of Queensland, Brisbane, Australia; and Institute of Bone and Joint Research (Ferreira), The Kolling Institute, Sydney Medical School, The University of Sydney, Australia.
Psychosom Med. 2018 Apr;80(3):263-270. doi: 10.1097/PSY.0000000000000548.
The aim of the study was to estimate the extent to which the co-occurrence of poor sleep quality and low back pain is due to the same genetic and/or environmental risk factors or due to a causal association.
Cross-sectional data on sleep quality (Pittsburgh Sleep Quality index) and low back pain were collected in a population-based sample of adult twins (N = 2134) registered with the Murcia Twin Registry. Bivariate analysis and structural equation modeling were used.
The phenotypic correlation between sleep quality and low back pain was 0.23 (95% confidence interval [CI] = 0.17-0.28). The best-fitting bivariate model included additive genetic and unique environmental factors. Genetic factors accounted for 26% (95% CI = 10-40) and 34% (95% CI = 25-43) of the variability of low back pain and sleep quality, respectively. The correlation between the genetic factors underlying each trait was rG of 0.33 (95% CI = 0.03-0.66), and this overlap of genetic factors explained 42.5% of the phenotypic correlation. On the other hand, nonshared environmental factors of each variable were only fairly correlated rE of 0.19 (95% CI = 0.06-0.31), although this overlap explained 57.5% of the phenotypic correlation. In addition, twins in monozygotic pairs with poorer sleep quality presented more often with low back pain than their co-twins (ρ^ = 0.25, p < .0001).
The data are compatible with a causal effect of sleep quality on low back pain (or the reverse effect), because the correlations between the genetic and unique environmental factors for each trait were significant and there was a significant correlation between the monozygotic twins' difference scores. Apart from environmental factors that affect both characteristics, there are many individual-specific events that influence low back pain but differ from those influencing sleep quality.
本研究旨在评估睡眠质量差和腰痛同时发生的程度，是由于相同的遗传和/或环境风险因素，还是由于因果关系。
在穆尔西亚双胞胎登记处注册的成年双胞胎的基于人群的样本中收集了睡眠质量（匹兹堡睡眠质量指数）和腰痛的横断面数据。采用双变量分析和结构方程模型。
睡眠质量和腰痛之间的表型相关性为 0.23（95%置信区间[CI] = 0.17-0.28）。最佳拟合的双变量模型包括加性遗传和独特的环境因素。遗传因素分别占腰痛和睡眠质量可变性的 26%（95%CI = 10-40）和 34%（95%CI = 25-43）。每个特征的遗传因素之间的相关性为 rG = 0.33（95%CI = 0.03-0.66），遗传因素的这种重叠解释了表型相关性的 42.5%。另一方面，每个变量的非共享环境因素仅适度相关 rE = 0.19（95%CI = 0.06-0.31），尽管这种重叠解释了表型相关性的 57.5%。此外，睡眠质量较差的同卵双胞胎的双胞胎比他们的同卵双胞胎更常出现腰痛（ρ^ = 0.25，p <.0001）。
数据与睡眠质量对腰痛（或相反的影响）有因果关系的说法一致，因为每个特征的遗传和独特环境因素之间的相关性显著，并且同卵双胞胎的差异分数之间存在显著相关性。除了影响这两个特征的环境因素外，还有许多影响腰痛但不同于影响睡眠质量的个体特定事件。
