Personalized mathematical model of endotoxin-induced inflammatory responses in young men and associated changes in heart rate variability

R. Brady, D. O. Frank-Ito, H. T. Tran, S. Janum, K. Møller, S. Brix, J. T. Ottesen, J. Mehlsen, M. S. Olufsen*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review


The objective of this study was to develop a personalized inflammatory model and estimate subject-specific parameters that could be related to changes in heart rate variability (HRV), a measure that can be obtained non-invasively in real time. An inflammatory model was developed and calibrated to measurements of interleukin-6 (IL-6), tumor necrosis factor (TNF-alpha), interleukin-8 (IL-8) and interleukin-10 (IL-10) over 8 hours in 20 subjects administered a low dose of lipopolysaccharide. For this model, we estimated 11 subject-specific parameters for all 20 subjects. Estimated parameters were correlated with changes in HRV, computed from ECG measurements using a built-in HRV module available in Labchart. Results revealed that patients could be separated into two groups expressing normal and abnormal responses to endotoxin. Abnormal responders exhibited increased HRV, most likely as a result of increased vagal firing. The observed correlation between the inflammatory response and HRV brings us a step further towards understanding if HRV predictions can be used as a marker for inflammation. Analyzing HRV parameters provides an easy, non-invasively obtained measure that can be used to assess the state of the subject, potentially translating to identifying a non-invasive marker that can be used to detect the onset of sepsis.

Original languageEnglish
Article number42
JournalMathematical Modelling of Natural Phenomena
Issue number5
Number of pages20
Publication statusPublished - 1 Jan 2018


  • Acute inflammation
  • Heart rate variability
  • Mathematical modeling
  • Parameter estimation

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