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Completed

NCT Number: NCT03313284

Respiratory Muscle Training and Intermittent Hypoxia: Additive Health Effects?

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.

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Key information

Conditions

Pre-Hypertension Cardiovascular Diseases Prehypertension Vascular Diseases

Age range

65 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Exercise Physiology Lab, Institute of Human Movement Sciences and Sport, ETH Zurich

Zurich, Canton of Zurich, 8057, Switzerland

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

  • 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

Treatment and study plan

RMT

Procedure

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

RMT + IH

Procedure

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.

Control

Procedure

No intervention

Primary outcomes

  1. Change in blood pressure in mmHg

    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

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

Secondary outcomes

  1. Change in pulse wave velocity in m/s

    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

    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

  2. Change in cardiac output in L/min

    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

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

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

    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

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

  4. Changes in baroreflex sensitivity in ms/mmHg

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

    Baroreflex sensitivity before and after each intervention assessed with photo plethysmography

  5. Change in heart rate variability in ms

    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

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

  6. Change in peripheral oxygenation during sleep in %Saturation

    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)

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

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

    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)

    Sleep efficiency measured at home after each intervention with an actigraph

  8. Change in subjective sleep quality

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

    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.

Sponsors and collaborators

Lead sponsor

Swiss Federal Institute of Technology

Other

Registry information

Official study title

Acute Effects of Intermittent Respiratory Muscle Training and Hypoxia on Cardiovascular and Sleep Parameters in Elderly Persons With Prehypertension

Important dates

Study start
2017
Primary completion
2018
Study completion
2018
First posted
Oct 18, 2017
Registry last updated
Aug 15, 2018

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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