Lutaif N A, Palazzo R, Gontijo J A R
Universidade Estadual de Campinas, Faculdade de Ciências Médicas, Departamento de Clínica Médica, CampinasSP, Brasil.
Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e Computação, Departamento de Telemática, CampinasSP, Brasil.
Braz J Med Biol Res. 2014 Jan;47(1):70-9. doi: 10.1590/1414-431X20133097. Epub 2014 Jan 17.
Maintenance of thermal homeostasis in rats fed a high-fat diet (HFD) is associated with changes in their thermal balance. The thermodynamic relationship between heat dissipation and energy storage is altered by the ingestion of high-energy diet content. Observation of thermal registers of core temperature behavior, in humans and rodents, permits identification of some characteristics of time series, such as autoreference and stationarity that fit adequately to a stochastic analysis. To identify this change, we used, for the first time, a stochastic autoregressive model, the concepts of which match those associated with physiological systems involved and applied in male HFD rats compared with their appropriate standard food intake age-matched male controls (n=7 per group). By analyzing a recorded temperature time series, we were able to identify when thermal homeostasis would be affected by a new diet. The autoregressive time series model (AR model) was used to predict the occurrence of thermal homeostasis, and this model proved to be very effective in distinguishing such a physiological disorder. Thus, we infer from the results of our study that maximum entropy distribution as a means for stochastic characterization of temperature time series registers may be established as an important and early tool to aid in the diagnosis and prevention of metabolic diseases due to their ability to detect small variations in thermal profile.
喂食高脂饮食(HFD)的大鼠体内热稳态的维持与其热平衡的变化有关。高热量饮食成分的摄入改变了散热与能量储存之间的热力学关系。观察人类和啮齿动物核心体温行为的热记录,有助于识别时间序列的一些特征,如自相关性和平稳性,这些特征足以进行随机分析。为了识别这种变化,我们首次使用了随机自回归模型,其概念与所涉及的生理系统相关,并且将其应用于雄性HFD大鼠,并与适当的标准食物摄入量、年龄匹配的雄性对照(每组n = 7)进行比较。通过分析记录的温度时间序列,我们能够确定新饮食何时会影响热稳态。自回归时间序列模型(AR模型)被用于预测热稳态的发生,并且该模型在区分这种生理紊乱方面被证明非常有效。因此,我们从研究结果推断,由于其能够检测热分布中的微小变化,最大熵分布作为一种对温度时间序列记录进行随机表征的手段,可能被确立为一种重要的早期工具,以帮助诊断和预防代谢疾病。