Investigation of association among psychology, sleepiness, autonomic function activity, and footbath

Abstract

【Background】

My previous study showed the altered parameter values obtained from pupillary light reflex (PLR) in healthy adults underwent footbath with warm water. The altered pattern indicated an increase of parasympathetic activity, but the involvement of sympathetic activity still remained unclear. In addition, the other factors such as sleepiness and psychological states can affect PLR. I investigated effects of the footbath on autonomic function, psychological states, and sleepiness.

【Methods】

Forty-five healthy adults underwent the Profile of Mood State (POMS), the Karolinska Sleepiness Scale (KSS), salivary alpha amylase, and PLR before and after the 10-minute footbath with 40℃ water. We investigated the association among the psychological states, sleepiness and autonomic activity due to footbath using exploratory factor analysis (EFA) and structural analysis of covariance (SEM).

【Results】

The intervention changed the values in all parameters. In EFA, some parameters displayed high loadings on three factors (Mood, pupil size, PLR). In the SEM, footbath contributed the pupil size (standardized estimates = 0.546) and PLR (standardized estimates = -0.604)

【Conclusion】

The altered pattern in PLR parameters and sAA indicated the enhanced parasympathetic activity due to the footbath. The change in PLR can be due to the transcutaneous stimulation rather than psychological states/sleepiness.