Department of Epidemiology, University Medical Center Groningen, University of Groningen, P.O. Box 30.001, 9700, RB, Groningen, The Netherlands.
Eur J Epidemiol. 2010;25(1):5-12. doi: 10.1007/s10654-009-9395-y. Epub 2009 Oct 22.
Obesity and physical inactivity are both risk factors for type 2 diabetes. Since they are strongly associated, it has been suggested that they might interact. In this study, we summarized the evidence on this interaction by conducting a systematic review. Two types of interaction have been discerned, statistical and biological interaction, which could give different results. Therefore, we calculated both types of interaction for the studies in our review. Cohort studies, published between 1999 and 2008, that investigated the effects of obesity and physical activity on the risk of type 2 diabetes were included. We calculated both biological and statistical interaction in these studies. Eight studies were included of which five were suitable to calculate interaction. All studies showed positive biological interaction, meaning that the joint effect was more than the sum of the individual effects. However, there was inconsistent statistical interaction; in some studies the joint effect was more than the product of the individual effects, in other studies it was less. The results show that obesity and physical inactivity interact on an additive scale. This means that prevention of either obesity or physical inactivity, not only reduces the risk of diabetes by taking away the independent effect of this factor, but also by preventing the cases that were caused by the interaction between both factors. Furthermore, this review clearly showed that results can differ depending on what method is used to assess interaction.
肥胖和身体活动不足都是 2 型糖尿病的危险因素。由于它们之间存在很强的关联，因此有人认为它们可能存在相互作用。在这项研究中，我们通过系统综述总结了这方面相互作用的证据。已经发现了两种类型的相互作用，即统计学相互作用和生物学相互作用，它们可能会产生不同的结果。因此，我们为综述中的研究计算了这两种类型的相互作用。纳入了 1999 年至 2008 年间发表的队列研究，这些研究调查了肥胖和身体活动对 2 型糖尿病风险的影响。我们在这些研究中计算了生物学和统计学的相互作用。共纳入了 8 项研究，其中 5 项适合计算相互作用。所有研究均显示出阳性的生物学相互作用，这意味着联合效应大于个体效应的总和。然而，统计学的相互作用并不一致；在一些研究中，联合效应大于个体效应的乘积，而在其他研究中则小于该乘积。结果表明，肥胖和身体活动不足在累加尺度上存在相互作用。这意味着预防肥胖或身体活动不足不仅可以消除该因素的独立作用从而降低糖尿病的风险，还可以预防因两个因素相互作用而导致的病例。此外，本综述清楚地表明，结果可能因用于评估相互作用的方法而异。
