Changes of Stress Markers by Footbath

Salivary IgA, urinary 8 (OH) dG and autonomic nervous balance

Abstract

Footbath is a safe and easy thermal therapy, however, it may cause stress on our body depending on the temperature. Temperature dependent changes of stress biomarkers in the saliva or urine, and of R-R variability by footbath were studied, and mechanism of effects and side effects were discussed.
Subjects were 14 healthy adult females (32±6 yeas old). The experiments started after permission of the Ethical Committee of International Research Center for Traditional Medicine. They took footbath at 38, 40, 42°C and control study after providing informed consents. They took footbath after 10min rest in a sitting position. Each footbath was 30min long, followed by 10min rest. The same subject participated in the studies four times at the same time of day before lunch. These experiments were in a random order four days apart each other except menstruation periods. Their ECG R-R variability and their concentration of salivary IgA and urinary 8 (OH) dG/creatinin were measured before and after footbath. The autonomic nervous balance was estimated from FFT analysis of the R-R variability; LF (0.04-0.15Hz) and HF (0.15-0.40Hz).
The results indicated that at 40 and 42°C their autonomic nervous balance estimated from LF/HF or HF power changed to sympathetic predominance. At 38, 40 and 42°C, salivary IgA increased significantly, and at 40 and 42°C, urinary 8 (OH) dG/creatinin increased significantly, while no significant change occurred in the control study.
These results indicated footbath for 30min at 40 and 42°C induced sympathetic predominance and caused oxidative stress. It was reported that oxidative stress induced activation of platelet aggregation. The oxidative stress as well as sympathetic activation may be related with the causes of the accidents during hot bathing as well as with the effects of thermal therapy. Further investigations are worth being performed.