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CompletedNCT03313284Updated Aug 15, 2018

Respiratory Muscle Training and Intermittent Hypoxia: Additive Health Effects?

An interventional study of RMT and RMT + IH in Pre-Hypertension, sponsored by Swiss Federal Institute of Technology. Completed at 1 site in Switzerland. Open to participants aged 65 Years to 80 Years. Per ClinicalTrials.gov, last updated 2018-08-15.

Sponsored by Swiss Federal Institute of Technology · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
14
Allocation
Not applicable
Ages
65 Years to 80 Years
Sex
All
01

Study summary

The prevalence of pre-hypertension and hypertension in the elderly is very high. Apart from medication, physical exercise training is a potential strategy to reduce blood pressure, however, the ability to perform exercise can be limited in the elderly. Hence, alternative non-pharmacological strategies to reduce blood pressure are necessary. Two interventions that have been shown to positively influence blood pressure are respiratory muscle training (RMT) and intermittent hypoxia (IH). Whether a combination of RMT and IH yields even better effects is currently unknown. Therefore, in this study, the effect of a single session of RMT with and without IH on blood pressure and associated cardiovascular parameters will be investigated in elderly subjects with pre-hypertension.

02

Conditions studied

  • Pre-Hypertension
03

Who can participate

Ages eligible
65 Years to 80 Years
Sexes eligible
All
Accepts healthy volunteers
No

Inclusion criteria

  • Age: 65-80 years
  • Systolic blood pressure between 130-139 mmHg and diastolic blood pressure lower than 90 mmHg
  • Non smoking
  • Normal Body-Mass-Index (BMI): 18.5-24.9 kg·m-2
  • Normal Lung Function
  • Willing to adhere to the general study rules

Exclusion criteria

Exclusion Criteria:

  • Known or suspected non-compliance, drug or alcohol abuse
  • Inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, dementia, etc. of the participant
  • Previous enrolment into the current study
  • Enrolment of the investigator, his/her family members, employees and other dependent persons
  • Intake of blood pressure medication
  • Intake of medications affecting sleep or the performance or the respiratory, cardiovascular or neuromuscular system
  • Acute or chronic illness other than prehypertension
04

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
14 participants (actual)

Study arms

  • Experimental
    Study Group

    Procedure: RMT · Procedure: RMT + IH · Procedure: Control

Interventions

  • ProcedureRMT

    RMT consists of six bouts of 5-min of volitional hyperpnoea . After each RMT bout, participants will breathe room air for 5 minutes.

  • ProcedureRMT + IH

    RMT and IH consist of six bouts of 5-min of volitional hyperpnoea. After each RMT bout, participants will breathe a hypoxic gas mixture (10.5% O2 ) for 5 minutes.

  • ProcedureControl

    No intervention

05

What researchers measure

Primary outcomes

  1. Change in blood pressure in mmHg

    Blood pressure before, during, and after each intervention measured with an automated sphygmomanometer

    Time frame: At baseline after 20 min of lying in a supine position, every 5 minutes during the 60 min intervention, and 20, 35 and 50 min after the end of the intervention

Secondary outcomes

  1. Change in pulse wave velocity in m/s

    Carotid-femoral pulse wave velocity before and after each intervention, assessed with a device that simultaneously records (non-invasively) pressure signals from the carotid and femoral arteries

    Time frame: At baseline after 25 min of lying in a supine position, and 25, 40 and 55 min after the end of the intervention

  2. Change in cardiac output in L/min

    Cardiac output before, during, and after each intervention measured with impedance cardiography

    Time frame: At baseline after 15min of lying in a supine position, every 5 minutes during the 60 min intervention, and 15, 30 and 45 min after the end of the intervention

  3. Change in total peripheral resistance in dyn x s/cm^5

    Total peripheral resistance before, during, and after each intervention measured with impedance cardiography

    Time frame: At baseline after 15min of lying in a supine position, every 5 minutes during the 60 min intervention, and 15, 30 and 45 min after the end of the intervention

  4. Changes in baroreflex sensitivity in ms/mmHg

    Baroreflex sensitivity before and after each intervention assessed with photo plethysmography

    Time frame: At baseline after 15min of lying in a supine position, and 15, 30 and 45 min after the end of the intervention

  5. Change in heart rate variability in ms

    Heart rate variability measured before, during and after each intervention with impedance cardiography

    Time frame: At baseline after 15min of lying in a supine position, every 5 minutes during the 60 min intervention, and 15, 30 and 45 min after the end of the intervention

  6. Change in peripheral oxygenation during sleep in %Saturation

    Peripheral oxygenation during sleep measured at home after each intervention with a finger pulse oxymeter

    Time frame: Continuously during the night following each intervention, from time to bed until wake up time in the morning (i.e. on average approximately 8hours)

  7. Change in sleep efficiency defined as the ratio of total sleep time and time in bed

    Sleep efficiency measured at home after each intervention with an actigraph

    Time frame: Continuously during the night following each intervention, from time to bed until wake up time in the morning (i.e. on average approximately 8hours)

  8. Change in subjective sleep quality

    Sleep quality (i.e. "How well did you sleep?" and "How recovered are you?") measured at home after each intervention with a visual analog scale (VAS). The two VAS consists each of a 10cm-horizontal line, with the left end of the lines representing low sleep quality ("slept very badly" and "not recovered at all", respectively) and the right end representing good sleep quality ("slept very well" and "completely recovered", respectively). Participants are asked to draw a vertical line in between the two ends on each of the two VAS.

    Time frame: Within 5 minutes after waking-up following the night after each intervention

06

Study locations

1 site
  • Exercise Physiology Lab, Institute of Human Movement Sciences and Sport, ETH Zurich
    Zurich, ZH 8057, Switzerland
07

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

08

Registry details

Key details

Study ID
NCT03313284
Lead sponsor
Swiss Federal Institute of Technology
Responsible party
Sponsor
First posted
Oct 18, 2017
Start date
Sep 29, 2017
Primary completion
Jul 4, 2018
Completion
Jul 4, 2018
Last update
Aug 15, 2018

Study contacts

Christina M. Spengler, Prof.
principal investigator · Exercise Physiology Lab, Institute of Human Movement Sciences and Sport, ETH Zurich

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
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