Intermittent Hypoxia-hyperoxia Conditioning as a New Therapeutic Intervention to Reduce Hypertension (HyperIHHC)

Summary

The primary objective of this project is to examine the efficiency of intermittent hypoxia-hyperoxia conditioning (IHHC) protocol to improve vascular health and reduce blood pressure in hypertensive patients (stage 1). The result of the present study will investigate if IHHC could be a therapeutic treatment for hypertensive individuals. The investigation is designed with a placebo intervention (air ambient) and a control group (age-matched healthy participants). The interest of short cycles of intermittent hypoxia-hyperoxia is due to the triggering of the vasodilatory response in a greater extent compared to the pressor mechanisms since the exposure duration remains short. Therefore, it can be hypothesized that control and hypertensive groups achieving IHHC may exhibit a decreased blood pressure compared to the control and hypertensive groups achieving placebo intervention. The control group may show greater change than hypertensive due to higher vascular reserve.

The secondary objective of the study is to understand the underlying mechanism of the beneficial effects of IHHC, especially the role of blood hemorheological changes. Based on available literature, it is know that hypoxia induce an increase in blood viscosity. One may hypothesize that with such a short hypoxic dose used during IHHC, only minor change in blood viscosity may occur. However, a slight rise in blood viscosity is known to stimulate NO synthase and then to produce more NO. Hence it could be one of the mechanisms involved in the early vasodilatory response to hypoxia. These findings are in line with the reported higher NO end-product metabolites during exercise in normoxia and hypoxia in subjects who showed a rise in blood viscosity after exercise. The hypothesis is that the magnitude of IHHC beneficial effects is related to change in blood viscosity and its determinants.

Conditions

• Hypertension

Interventions

OTHER

Intermittent hypoxia-hyperoxia conditioning

The IHHC protocol consist of 6 bouts of 6 min breathing hypoxia (FiO2 = 11.5%) following by 3 min breathing hyperoxia (FiO2 = 31.5%) (Figure 2). The total duration of a session is 54 minutes. Participant will undergo 3 session a week for 6 weeks. During the session, participant will be comfortably seated on an armchair and equipped with a mask and a non-rebreathing valve rely to a motorized valve that blindly change the gas input from two different mixing chambers with hypo and hyperoxic gas mixture. Participants will be instructed to relax and breath normally throughout the session.

OTHER

Placebo intervention

Placebo intervention will be like the IHHC protocol but with mixing chambers full of ambient air. The total duration of a placebo session is 54 minutes. Participant will undergo 3 session a week for 6 weeks. During the session, participant will be comfortably seated on an armchair and equipped with a mask and a non-rebreathing valve rely to a motorized valve that blindly change the gas input from two different mixing chambers with ambient air. Participants will be instructed to relax and breath normally throughout the session.

Sponsors & Collaborators

• Centre Hospitalier Universitaire Vaudois

  collaborator OTHER

• Gregoire Millet

  lead OTHER

Principal Investigators

• Grégoire P Millet, PhD · University of Lausanne

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

44 Years

Max Age

64 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2022-11-15

Primary Completion

2023-05-15

Completion

2023-05-15

Countries

• Switzerland

Study Locations