Key result
Half-body immersion resulted in a slower increase in core temperature, cardiac output, and sympathetic activity compared to whole-body immersion, suggesting it is a safer alternative for systemic thermal therapy.
Why the study?
Does half-body immersion compared to whole-body immersion alter cardiovascular and thermal responses in healthy men?
Does half-body immersion compared to whole-body immersion alter cardiovascular and thermal responses in healthy men?
Absolute Event Rate: 37.3% vs 37.9%
p-value: p=0.03
Whole-body immersion induces greater increases in cardiac output and core temperature compared to half-body immersion in healthy men.
May blunt hemodynamic stress in thermal therapy; hypothesis-generating in healthy men and should not yet change practice.
Background and Objectives：The beneficial effects of systemic thermal therapy such as taking a hot tub or sauna have been described for patients with cardiovascular disease. Despite such positive effects, there is still concern over the safety of these procedures. Half-body immersion has recently been widely used as an alternative to achieve the same benefit, and it is better tolerated than conventional whole-body immersion (WBI). However, there has been no study that has clarified the cardiovascular effect of half-body immersion (HBI). Subjects and Methods：We asked 13 healthy men (age：20 to 27 years) to immerse themselves to the shoulder level on day 1) and to the umbilical level on Day 2 for 20 minutes in a hot tub, respectively (tempera-ture：39.0 to 41.0℃). Changes of skin (TSk) and esophageal temperature (TEo), hemodynamic and autonomic responses, and symptom scale were measured during the immersion. Results：All the volunteers were com-pliant and there were no adverse events. During immersion, the TEo increased continuously with each methods, but 10 minutes after immersion the TEo for the WBI patients was higher (p=0.03). The heart rate (HR) increased and the diastolic blood pressure decreased for both conditions. In contrast to HBI, the ejection fraction (EF) (p=0.10), and cardiac output (CO)(p=0.005) increased continuously for WHI. Among the HRV parameters, the values for the low-to-high frequency ratio (p=0.03) increased significantly with WHI after 10 minutes. The
No takes yet. Share an insight, caveat, or question.
Kim et al. (2004) studied Healthy volunteers (n=13). Half-body immersion vs. Whole-body immersion was evaluated on Esophageal temperature (TEo) at 20 minutes (p=0.03). Half-body immersion resulted in a slower increase in core temperature, cardiac output, and sympathetic activity compared to whole-body immersion, suggesting it is a safer alternative for systemic thermal therapy.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: