Influence of Different Temperature Warm Bathing on Arterial Stiffness in Elderly Subjects / 日本温泉気候物理医学会雑誌

ABSTRACT

  Purpose: Age-associated changes in arterial structure and function increase risk of cardiovascular disease. Previous studies have found that the body temperature response might influence acute changes in arterial stiffness after exercise. However, the relationship between increased body temperature during warm bathing and arterial stiffness has not been clarified. Therefore, the present study aimed to determine the effects of increases in body temperature by bathing in warm water on arterial stiffness in elderly subjects.  Methods: Healthy elderly 8 subjects (8 males, mean age ± standard error 61.1 ± 1.1 years) bathed in water at 35°C, 38°C, and 40°C for 15 min. Carotid-femoral pulse wave velocity (aortic PWV) and femoral-ankle PWV (leg PWV), blood pressure, heart rate, and rectal temperature were measured at baseline and at 30 and 60 min after bathing, in a quiet and air-conditioned room at the same time in the morning.  Results: Rectal temperature was significantly increased at 30 and 60 min after bathing at 38°C and 40°C, whereas leg PWV significantly decreased. Heart rate significantly increased at 30 and 60 min after bathing at 40°C. Blood pressure did not change after bathing at any temperature.  Conclusion: The present study showed that leg PWV significantly decreased in elderly subjects after bathing at 40°C, but not at 35°C and 38°C. However the underlying mechanism of the decrease remains unknown and these effects might depend on increased body temperature. Thus, it is suggested that warm bathing might affect the decrease in leg arterial stiffness.