2023 Volume 37 Issue 2 Pages 162-172
Purpose
This study aimed to investigate the effects of back heat therapy on the stress and the mammary blood flow in nonpregnant, nonlactating women.
Participants and Methods
The participants were 21 women aged 20–41 years (23.6 ± 5.3 years) who were in non-pregnant/non-lactating periods and whose menstrual cycle was in the follicular phase. The same study participants back heat therapy (heat therapy group) and underwent supine resting (rest group) at the same time of the day on different days, and the results of the two groups were compared. The experimental procedure included the following stages: pre-intervention rest, intervention (back heat therapy or supine rest), and post-intervention rest, with each stage lasting for 15 minutes. Stress levels of the participants were evaluated by measuring the levels of cortisol and human herpesvirus 6 and 7 (HHV6 and HHV7) in saliva samples and using a 9-level Likert scale, with scores ranging from 1 (uncomfortable) to 9 (comfortable). Notably, the samples were collected before and after intervention and the end of the experiment. During the experiment, mammary blood flow was continuously measured using a laser Doppler flowmeter, and the average values were calculated every 5 minutes.
Results and Discussion
There were no significant differences in cortisol and HHV6 and HHV7 levels between the heat and rest groups; however, the heat therapy group reported a significantly higher level of comfort than the rest group (p < .01) on the Likert scale. Although back heat therapy induced a state of comfort in the participants, it did not significantly affect stress levels. A significant relationship was observed between the intervention method and time during the measurement of the mammary blood flow. Further, owing to the significant main effect of time, multiple comparisons were performed. The heat group exhibited significant differences at all time points after intervention compared with the baseline values obtained before intervention (p < .05, p < .01, and p < .05), whereas the rest group exhibited significant differences during the first 5–10 min of intervention and at all time points after intervention (all p < .01). Notably, both groups exhibited significant changes in mammary blood flow after intervention, but there were no significant differences between the two groups in terms of in mammary blood flow. Back heat therapy did not have a significant effect on mammary blood flow during intervention, but it was suggested to promote mammary blood flow after intervention. However, it is also possible that supine rest itself promoted mammary blood flow after intervention.
Conclusion
I found that back heat therapy induced a higher level of comfort than supine rest. Additionally, the results of my study suggested that back heat therapy promotes mammary blood flow after intervention but does not affect the flow during intervention.
