Relationship between heart rate variability parameters and inflammatory activity in patients with Crohn's disease: a retrospective study.

Background: It is widely recognized that individuals with Crohn's disease (CD) often experience impaired autonomic nervous system (ANS) function. However, the specific relationship between autonomic activity and inflammatory processes in CD remains uncertain. The objective of this study was to investigate the association between autonomic nervous function, as assessed through heart rate variability (HRV) parameters, and the Crohn's disease activity index (CDAI).

Methods: This cross-sectional study involved 82 CD patients. Demographic and medical history data were gathered, and disease activity was evaluated using the CDAI. Short-term HRV measurements were obtained from all participants.

Results: Various adjustments to the model and trend analysis indicate that the HRV parameters are significantly negatively correlated with CDAI. After controlling for potential confounding factors, the smooth curve fitting shows that high-frequency (HF) power is negatively linearly correlated with CDAI. As the HF value increases, CDAI shows a decreasing trend. In contrast, total power (TP), low-frequency power (LF), and standard deviation of the R-R interval (SDNN) exhibit a nonlinear relationship with CDAI. To the left of the inflection point, as the values of TP, LF, and SDNN increase, CDAI shows a decreasing trend. However, to the right of the inflection point, there is no relationship between TP, LF, SDNN values, and CDAI.

Conclusion: In patients with CD, autonomic dysfunction correlates with active inflammation. Among the HRV parameters, HF, which reflects vagal-mediated activity, displayed the strongest and most consistent negative correlation with inflammatory activity.