Madrid-Valero Juan J, Martínez-Selva José M, Ordoñana Juan R
Department of Human Anatomy and Psychobiology, University of Murcia, Murcia, Spain.
Murcia Institute of Biomedical Research, IMIB-Arrixaca, Murcia, Spain.
J Sleep Res. 2017 Aug;26(4):461-467. doi: 10.1111/jsr.12493. Epub 2017 Jan 19.
There is a consistent relationship between body mass index and sleep quality. However, the directionality and possible confounding factors of this relationship are unclear. Our aim is to confirm the association between sleep quality and body mass index, independent of possible genetic confounding, as well as to provide some indirect inferences about the directionality of this association. The co-twin study design was used to analyse the body mass index-sleep relationship in a sample of 2150 twins. We selected two parallel sub-samples of twins discordant for body mass index (n = 430 pairs), or discordant for sleep quality (n = 316 pairs). Sleep quality and body mass index showed an inverse relationship (b = 0.056, P = 0.032) in the global sample. When twins discordant for body mass index were selected, this association maintained a similar effect size and statistical significance, at all levels of the case-control analysis (all discordant pairs b = 0.173, P < 0.001; dizygotic twins b = 0.174, P = 0.002; monozygotic twins b = 0.173, P = 0.050). Nevertheless, when twin pairs were selected on the basis of their discordance for sleep quality, the association between body mass index and sleep quality appeared weaker and lost significance (b = 0.021, P = 0.508). The analyses including only dizygotic (b = 0.028, P = 0.526) or monozygotic (b = 0.001, P = 0.984) pairs produced similar non-significant results. Our results confirm the relationship between sleep quality and body mass index, even after applying high levels of control, including genetic factors. Moreover, this study suggests a possible directionality of this relationship, such that sleep quality would strongly affect body mass index, while the opposite would be less robust and consistent in non-clinical samples.
体重指数与睡眠质量之间存在一种稳定的关系。然而，这种关系的方向性以及可能的混杂因素尚不清楚。我们的目的是确认睡眠质量与体重指数之间的关联，排除可能的基因混杂因素，并对这种关联的方向性提供一些间接推断。采用共双胞胎研究设计，对2150对双胞胎样本中的体重指数与睡眠关系进行分析。我们选取了两个平行子样本，一组是体重指数不一致的双胞胎（n = 430对），另一组是睡眠质量不一致的双胞胎（n = 316对）。在总体样本中，睡眠质量与体重指数呈负相关（b = 0.056，P = 0.032）。当选取体重指数不一致的双胞胎时，在病例对照分析的各个层面，这种关联都保持了相似的效应量和统计学显著性（所有不一致对b = 0.173，P < 0.001；异卵双胞胎b = 0.174，P = 0.002；同卵双胞胎b = 0.173，P = 0.050）。然而，当根据睡眠质量不一致来选取双胞胎对时，体重指数与睡眠质量之间的关联似乎较弱且失去了显著性（b = 0.021，P = 0.508）。仅包括异卵（b = 0.028，P = 0.526）或同卵（b = 0.001，P = 0.984）双胞胎对的分析产生了类似的无显著性结果。我们的结果证实了睡眠质量与体重指数之间的关系，即使在应用了包括基因因素在内的高水平控制之后。此外，本研究提示了这种关系可能的方向性，即睡眠质量会强烈影响体重指数，而在非临床样本中，相反的情况则不那么稳健和一致。
