NCT05300971

Passive Heat Therapy for Lowering Systolic Blood Pressure and Improving Vascular Function in Mid-life and Older Adults

• Status: Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 150 (estimated)
• Sponsor: University of Colorado, Boulder · Academic / Other
• Sex: All
• Age: 40 Years
• Healthy volunteers: Accepted

Summary

This study aims to determine the effects of \~12 weeks of repeated hot water immersion ("heat therapy") vs. thermoneutral water immersion on blood pressure and vascular function in late middle-life to older (≥40 years) adults. The study also aims to determine the effects of \~12 weeks of heat therapy on fluid cognitive and cerebrovascular function.

Detailed description

Advancing age is the primary risk factor for cardiovascular diseases (CVD), which remain the leading cause of death in the developed world. The key process that links aging to increased risk of CVD is increases in systolic blood pressure and the development of arterial dysfunction (i.e., impaired endothelial function and arterial stiffening). Passive heat therapy, in the form of repeated use of hot baths and saunas, has been used by several cultures for centuries; however, the physiological benefits are only now being elucidated. For example, recent studies have found that lifelong habitual sauna use is associated with considerably reduced risk of all-cause mortality, sudden cardiac death, CVD-related death. In addition, 8-10 weeks of hot water immersion in young adults has been shown to improve endothelial function and reduces arterial stiffness and blood pressure. Therefore, the investigators expect heat therapy to similarly improve blood pressure and vascular function in middle-life and older adults who are at greater risk of CVD. Aging is also the primary risk factor for Alzheimer's disease and related dementias, as well as mild cognitive impairment (MCI). Above-normal systolic blood pressure (SBP; ≥115 mmHg) further increases risk of dementias, due, in part, to SBP-associated cerebrovascular dysfunction, i.e., impaired cerebral blood flow regulation. Accordingly, midlife and older adults with above-normal SBP are at the highest risk for cognitive decline driven by vascular contributions to cognitive impairment and dementias in this age group. Excessive reactive oxygen species-induced oxidative stress and reductions in nitric oxide (NO) bioavailability within the cerebral vasculature likely mediate cerebrovascular dysfunction with aging and contribute to MCI and Alzheimer's disease and related dementias in those with above-normal SBP.

Conditions

• Aging

Interventions

Type	Name	Description
OTHER	Heat therapy	36 sessions (\~3x per week for 12 weeks) of hot water immersion in 40°C water, sufficient to raise body core temperature to 38.5°C, and 12 weeks of follow-up.
OTHER	Thermoneutral water immersion	36 sessions (\~3x per week for 12 weeks) of thermoneutral water immersion in 36°C water to prevent changes in body core temperature \>0.2°C, and 12 weeks of follow-up.

Timeline

• Start date: 2022-08-01
• Primary completion: 2027-11-01
• Completion: 2028-02-01
• First posted: 2022-03-29
• Last updated: 2025-04-29

Locations

1 site across 1 country: United States