Ambulatory blood pressure monitoring during hot-water bathing in winter using radial pulse wave acquisition device

2021 Fiscal Year Final Research Report

• Project/Area Number: 18K15899
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 53020:Cardiology-related
• Research Institution: Nara Medical University
• Principal Investigator: Yoshiaki Tai 奈良県立医科大学, 医学部, 助教 (60812394)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Keywords: 入浴関連死 / 自由行動下血圧 / 皮膚温 / 疫学研究

Outline of Final Research Achievements

The number of bath-related deaths per year exceeds that of death from traffic accidents in Japan. Bath-related death increases in winter, especially among older adults. However, the hemodynamic changes during bathing and mechanisms underlying bath-related death are unclear. Hence, in real-life situations, we measured ambulatory blood pressure and skin temperatures for 24 consecutive hours among Japanese older adults. We showed that systolic and diastolic blood pressure peaked just after soaking in the bathtub and that pulse rate continued rising for about 15 minutes after soaking in the bathtub. In addition, the skin temperature as a measure of heat exposure was positively correlated with blood pressure and pulse rate. We estimated the change in blood pressure and pulse rate during soaking in the hot tub compared to before bathing.

Free Research Field

疫学

Academic Significance and Societal Importance of the Research Achievements

脈波自由行動下血圧計を用いることで、実生活下、浴槽入浴中の血圧・脈拍変化を初めて報告した。皮膚温の同時測定により、入浴による温熱曝露の程度と血圧・脈拍との関連を明らかにした。過去の類似研究は、主に若年者を対象とした制御環境下の結果に限られてきたため、本研究成果は、家庭内で特に高齢者に生じる入浴関連死の機序解明・予防法確立につながる結果であるとか考える。血圧・脈拍の変動を抑制する入浴方法を提示することで、急激な血行動態変化によって生じうる心血管疾患、意識消失とそれに引き続く溺水を予防できる可能性を示唆した。