None listed
Conditions
Brief summary
IMT has been recognised as a novel form of resistance training in recent years, generating surprising results including improved blood pressure and autonomic balance in patients with hypertension. OSA . and reductions in systemic vascular resistance in healthy young adults. The findings are impressive as each study was able to attain these results within a simple 6-week training program consisting of only 5 min/day for 5 days/week or 25 min/week total training time. There is evidence that IMT performed daily improves casual blood pressure and plasma catecholamines in adults with OSA and elevated or stage 1 hypertension. The effect IMT has on 24-hour blood pressure, a better predictor of blood pressure related end-organ damage, requires further elucidation. A recent study has found reduced systolic blood pressure with high resistance IMT in OSA patients with moderate-to-severe OSA. However, the effect of high and low resistance training on patients with OSA and existing hypertension remains unclear. We hypothesise that high-intensity IMT training will result in lower blood pressure for obstructive sleep apnoea patients with hypertension. We hypothesise that IMT will improve obstructive sleep apnoea severity in patients with hypertension. We hypothesise that IMT will be a well-tolerated device for reducing blood pressure in this group.
Interventions
Investigators:
The study investigator: A PhD candidate who has been trained to use the VMax machine and undertake the respiratory function tests required to calibrate the IMT device. The study investigator will also demonstrate/ train study participants on how to use their IMT devices. In addition, the study investigator has also been trained to perform all autonomic and hemodynamic tests in this study.
Sleep Physician: The Principal Investigator is a sleep physician who will be responsible f
Investigators: The study investigator: A PhD candidate who has been trained to use the VMax machine and undertake the respiratory function tests required to calibrate the IMT device. The study investigator will also demonstrate/ train study participants on how to use their IMT devices. In addition, the study investigator has also been trained to perform all autonomic and hemodynamic tests in this study. Sleep Physician: The Principal Investigator is a sleep physician who will be responsible for the recruitment of suitable study candidates. Recruitment: Participants presenting to a sleep clinic (Royal North Shore Hospital) will be approached for recruitment by the treating sleep physician. The inclusion criteria dictate that all patients selected for recruitment will have a history of hypertension and OSA. Visits: All face-to-face study visits will take place at The Charles Perkins Centre, Royal Prince Alfred Hospital Clinic, University of Sydney Study visits: Visit 1 (5 minutes): Participants to provide formal written consent before they are randomised to receive High or low-Intensity Inspiratory Muscle Training (IMT) using Threshold IMT (Philips Respironics, Sussex, UK). Visit 2 (30 minutes): A face-to-face visit with the study investigator will be undertaken where the participant will be set-up with 24-hour ambulatory blood pressure (15 minutes). They will return this device the following day. An e-mail will be sent with a link to Questionnaires (Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale and SF-36 Short Form Health Survey) that will require completion the same night at home (15 minutes). Visit 3 (1.5 hour): The morning following visit 2 the blood pressure monitor will be returned. The study investigator will perform respiratory function tests on the participant to determine maximal inspiratory pressure and calibrate the IMT device accordingly. Baseline measures to be undertaken: Autonomic and haemodynamic tests (electrocardiography, finger photoplethysmography, and pulse wave analysis). Participants will be sent home with their newly calibrated IMT device. They will be shown how to use the device by the study investigator. Participants will be prescribed training for 5 minutes per day/ 7 days a week for 6 weeks. At the 3-week mark, participants will be asked to return to the clinic for visit 4. Compliance will be assessed subjectively using a device use log. Participants will be contacted by phone each week by the study investigator to encourage compliance and assist with any issues related to the study. Visit 4 (30 minutes): respiratory function tests and device recalibration. Participants will use these settings for the remainder of the training program. Visit 5 (30 minutes): After 6 weeks of treatment, participants will return for a face-to-face visit where a 24-hour ambulatory blood pressure monitor will be set up (15 minutes) and questionnaires will be completed that day. An additional questionnaire assessing the participant's response to treatment will also be completed (15 minutes). Visit 6 (1.5 hours): Participants will return the next morning for a face-to-face visit. The 24-hr blood pressure monitor will be returned. Final autonomic and respiratory function tests will be completed. Participants will be sent home to repeat the final sleep study and the device will be returned at their earliest convenience. IMT: This device acts as an inspiratory muscle trainer that will help increase respiratory muscle strength and endurance through conditioning. Participants breathe into a mouthpiece which is connected to the inspiratory muscle trainer. The device contains a pressure loaded inspiratory valve and an unloaded expiratory flap valve. This allows for resistance upon inspiration only and can be manually shifted to provide higher or lower resistance. Participants are randomised to receive low or high resistance IMT. High resistance: Devices will be calibrated to 75% of the maximal inspiratory mouth pressure for each participant. Low resistance: Devices will be calibrated to 15% of the maximal inspiratory mouth pressure for each participant.
Sponsors
University of Sydney
Study design
Allocation
Randomised controlled trial
Intervention model
Parallel
Primary purpose
Treatment
Masking
Blinded (masking used) (Subject, Investigator)
Eligibility
Sex/Gender
All
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
• Participants presenting to a sleep clinic (Royal North Shore Hospital) • Adults (male and female) • Willingness to undergo IMT for 6 weeks. • Willingness to provide informed consent and willingness to participate and comply with the study requirements.
Exclusion criteria
• Previous or current OSA treatment. • Women who are lactating or pregnant • Driving risk, report an accident (or near miss accident) because of sleepiness in the last 6 months • Need for immediate therapy as assessed by treating sleep physician. • Patients with a history of psychological illness or conditions such as to interfere with the patient’s ability to understand the requirements of the study • Previous history of pneumothorax • Burst eardrum or other conditions of the eardrum • Unstable asthma with an abnormally low perception of dyspnoea • Coexisting sleep disorder, shift work, regular use of sedatives or narcotics, pre-existing lung disease (moderate to severe chronic obstructive pulmonary disease) or psychiatric disease; chronic kidney disease (eGFR<60). • Central sleep apnea >10% of respiratory events being central events, rather than obstructive events.
Outcome results
None listed