Inspiratory Muscle Strength Training in Chronic Kidney Disease

April 29, 2025 updated by: University of Colorado, Denver

Inspiratory Muscle Strength Training for Lowering Systolic Blood Pressure in Midlife and Older Adults With Chronic Kidney Disease

More than 80% of individuals with chronic kidney disease have concomitant hypertension and the majority fail to achieve blood pressure control <130/80 mmHg, leading to high risk of cardiovascular diseases and end-stage kidney disease. A stepwise combination of lifestyle modifications and drug therapy is recommended to lower blood pressure; however, adherence to time-intensive lifestyle interventions such as aerobic exercise in patients with chronic kidney disease is poor. This clinical trial seeks to establish the efficacy of high-resistance inspiratory muscle strength training, a novel time-efficient lifestyle intervention, for lowering systolic blood pressure and improving endothelial function in midlife and older adults with moderate-to-severe chronic kidney disease and inadequately controlled hypertension, and to use innovate translational assessments to understand the mechanisms involved.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Chronic kidney disease (CKD) is a major public health concern that has reached epidemic proportions. Hypertension is a leading modifiable risk factor for cardiovascular disease (CVD) and end-stage kidney disease, yet 50-70% of adults with CKD fail to achieve blood pressure (BP) control to <130/80 mmHg. A key process linking high systolic BP (SBP) to CVD is vascular endothelial dysfunction, which is due in part to increased reactive oxygen species and decreased nitric oxide. Nitric oxide is also critical in the regulation of renal blood flow, which is intimately related to blood pressure and vascular function. High-resistance inspiratory muscle strength training (IMST) is a novel lifestyle intervention involving repeated inhalations against a resistive load using a hand-held device. This study will test whether high-resistance IMST (75% of maximal inspiratory pressure [75% PImax]; 30 breaths [5 min]/day, 6 days [30 min]/week) vs. Sham training (15% PImax) reduces resting systolic blood pressure in midlife and older adults (>50 years) with moderate-to-severe CKD and inadequately controlled hypertension. Changes in 24-hr systolic blood pressure and endothelial function (brachial artery flow-mediated dilation) are secondary outcomes. Innovative translational techniques will be used to provide mechanistic insight, including serum incubation in endothelial cell culture, metabolomics analysis, endothelial cell collections, and assessment of renal blood flow by magnetic resonance imaging. Changes and cerebrovascular and cognitive function will be assessed as part of a sub-study.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
108

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

  • Name: Emily Andrews
  • Phone Number: 303-724-7790

Study Locations

  • United States
    • Colorado
      • Aurora, Colorado, United States, 80045
        • Recruiting
        • University of Colorado - Anschutz Medical Campus
        • Principal Investigator:
          • Michel Chonchol, MD
        • Contact:
        • Contact:
        • Principal Investigator:
          • Kristen Nowak, PhD, MPH

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

50 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Aged 50 years or older; women must be post-menopausal
  • Chronic kidney disease stage 3 or 4 (estimated glomerular filtration rate with the 4 CKD-EPI 2021 race-free equation: 20-59 mL/min/1.73m^2; stable renal function in the past 3 months)
  • History of inadequately controlled hypertension (systolic blood pressure 120-159 mmHg on two separate days) and on a stable antihypertensive regimen for the past 6 weeks
  • Weight stable in the prior 3 months (<2 kg weight change) and willing to remain weight stable throughout the study. Participants using glucagon-like peptide-1 receptor agonists or planning to start them during the study are excluded unless they have achieved weight stability for at least 3 months prior to enrollment.
  • Ability to provide informed consent

Exclusion Criteria:

  • Patients with advanced chronic kidney disease requiring chronic dialysis
  • Significant pulmonary disorders including: chronic obstructive pulmonary disease, interstitial lung disease, cystic fibrosis, or uncontrolled asthma
  • History of spontaneous pneumothorax, collapsed lung due to traumatic injury that has not fully healed, burst eardrum that has not fully healed, or other conditions of the eardrum
  • Significant co-morbid conditions with a life expectancy of < 1 year
  • History of severe congestive heart failure (i.e., ejection fraction <35%)
  • History of hospitalization within the last month
  • Albuminuria (albumin to creatinine ratio > 2200 mg/g
  • Current smoker
  • Immunosuppressant agents taken in the past 12 months. Steroids used for the treatment of gout are acceptable; however, patients should not be using steroids within 2 weeks (or 14 days) prior to the vascular testing (rationale: may confound vascular testing)
  • Known malignancy
  • Inability to cooperate with or clinical contraindication for magnetic resonance imaging including: severe claustrophobia, implants, devices, or non-removable body piercings (these individuals can participate in the study but are excluded from the MRI procedure)
  • Illicit drug use or alcohol dependence/abuse, which in the opinion of the investigators, would prohibit compliance with the study intervention

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: IMST
This group will perform high-resistance (75% of maximal inspiratory pressure) inspiratory muscle strength training (IMST), 30 inhalations/session, 6 days/week.
Device: IMST
Inspiratory muscle strength training (IMST) is a form of physical training that utilizes the diaphragm and accessory respiratory muscles to repeatedly inhale against resistance using a handheld device.
Sham Comparator: Control
This group will perform low-resistance (15% of maximal inspiratory pressure) inspiratory muscle strength training, 30 inhalations/session, 6 days/week.
Device: Sham Training
Repeated inhalations against a low resistance will be performed using a handheld device.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in Casual Systolic Blood Pressure
Time Frame: Baseline, 3 months
Casual (resting) measures of systolic blood pressure (mmHg) will be measured in triplicate over the brachial artery of the non-dominant arm after 5 minutes of quiet rest, with 1 minute of recovery between each measure, using an automated oscillometric sphygmomanometer.
Baseline, 3 months

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in 24-Hour Ambulatory Systolic Blood Pressure
Time Frame: Baseline, 3 months
Brachial artery systolic blood pressure (mmHg) will be measured automatically every 20 minutes for a 24-hour period by an ambulatory blood pressure monitor and will be averaged over the entire 24-hour period.
Baseline, 3 months
Change in Brachial Artery Flow-Mediated Dilation
Time Frame: Baseline, 3 months
Flow-mediated dilation of the brachial artery will be performed using ultrasonography and analyzed with a commercially available software package as percent change in diameter from baseline following reactive hyperemia.
Baseline, 3 months

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in Ex Vivo Reactive Oxygen Species Production
Time Frame: Baseline, 3 months
Human umbilical vein endothelial cells will be incubated with basal media supplemented with 10% human serum collected from participants and stained with the fluorescent probe CellROX Deep Red to detect reactive oxygen species production.
Baseline, 3 months
Change in Endothelial Cell Protein Expression of MnSOD
Time Frame: Baseline, 3 months
In a sub-group of participants, endothelial will be obtained from peripheral veins via endovascular biopsy, recovered by centrifugation, fixed, and analyzed for protein expression of MnSOD in collected endothelial cells relative to human umbilical vein endothelial cells using immunofluorescence.
Baseline, 3 months
Change in Endothelial Cell Protein Expression of NADPH oxidase
Time Frame: Baseline, 3 months
In a sub-group of participants, endothelial will be obtained from peripheral veins via endovascular biopsy, recovered by centrifugation, fixed, and analyzed for protein expression of NADPH oxidase in collected endothelial cells relative to human umbilical vein endothelial cells using immunofluorescence.
Baseline, 3 months
Change in Endothelial Cell Abundance of Nitrotyrosine
Time Frame: Baseline, 3 months
In a sub-group of participants, endothelial will be obtained from peripheral veins via endovascular biopsy, recovered by centrifugation, fixed, and analyzed for abundance of nitrotyrosine in collected endothelial cells relative to human umbilical vein endothelial cells using immunofluorescence.
Baseline, 3 months
Change in Renal Blood Flow
Time Frame: Baseline, 3 months
Magnetic resonance imaging will be used to determine flow of the renal arteries.
Baseline, 3 months
Adherence
Time Frame: 3 months
Adherence will be evaluated as percent of completed training sessions at the required workload using data stored on the training device.
3 months
Safety (adverse events)
Time Frame: 3 months
Safety will be evaluated as the number of participants with treatment-related adverse events in each group.
3 months
Tolerability (drop-out due to adverse events)
Time Frame: 3 months
Tolerability will assessed as the rate at which enrolled subjects drop out due to adverse events.
3 months
Change in Casual Diastolic Blood Pressure
Time Frame: Baseline, 3 months
Casual (resting) measures of diastolic blood pressure (mmHg) will be measured in triplicate over the brachial artery of the non-dominant arm after 5 minutes of quiet rest, with 1 minute of recovery between each measure, using an automated oscillometric sphygmomanometer.
Baseline, 3 months
Change in 24-Hour Ambulatory Diastolic Blood Pressure
Time Frame: Baseline, 3 months
Brachial artery diastolic blood pressure (mmHg) will be measured automatically every 20 minutes for a 24-hour period by an ambulatory blood pressure monitor and will be averaged over the entire 24-hour period.
Baseline, 3 months
Change in Endothelium-Independent Dilation
Time Frame: Baseline, 3 months
Endothelium-independent dilation will be determined using ultrasonography and analyzed with a commercially available software package as percent chance in brachial artery diameter following 0.4 mg of sublingual nitroglycerin.
Baseline, 3 months
Change in Ex Vivo Nitric Oxide Production
Time Frame: Baseline, 3 months
Human umbilical vein and/or cerebral endothelial cells will be incubated with basal media supplemented with 10% human serum collected from participants and stained with the fluorescent probe DAF-FM diacetate to detect nitric oxide production production in response to acetylcholine.
Baseline, 3 months
Change in Ex Vivo HUVEC eNOS Activation
Time Frame: Baseline, 3 months
Human umbilical vein and/or endothelial cells will be treated with 10% human serum and protein expression of cell lysates will be determined by capillary electrophoresis immunoassay.
Baseline, 3 months
Change in middle cerebral artery cerebrovascular reactivity
Time Frame: Baseline, 3 months
Change in middle cerebral artery velocity in response to hypercapnia
Baseline, 3 months
Change in internal carotid artery cerebrovascular reactivity
Time Frame: Baseline, 3 months
Internal carotid artery diameter in response to hypercapnia
Baseline, 3 months
Change in middle cerebral artery pulsatility index
Time Frame: Baseline, 3 months
Pulsatility index of the middle cerbral artery via transcranial doppler
Baseline, 3 months
Change in brain blood flow
Time Frame: Baseline, 3 months
Total brain blood flow measured via ultrasonography of the internal carotid and vertebral arteries
Baseline, 3 months
Change in NIH toolbox cognitive function
Time Frame: Baseline, 3 months
Total composite score using the NIH toolbox exam
Baseline, 3 months
Change in executive function
Time Frame: Baseline, 3 months
Time to complete the trailmaking test part B
Baseline, 3 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Colorado, Denver

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
University of Colorado, Boulder

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Michel Chonchol, MD, University of Colorado, Denver
  • Principal Investigator: Kristen Nowak, PhD, MPH, University of Colorado, Denver

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
March 1, 2022

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 1, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
July 1, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
May 25, 2021

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 27, 2021

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 3, 2021

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 2, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 29, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
April 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 21-3000
  • R01DK130255 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Data obtained through this study may be provided to qualified researchers with academic interest in CKD. Data shared will be coded, with no PHI included. Approval of the request and execution of all applicable agreements (i.e. data use agreement) are prerequisites to the sharing of data with the requesting party.

IPD Sharing Time Frame

Data requests can be submitted starting 9 months after article publication and the data will be made accessible for up to 24 months. Extensions will be considered on a case-by-case basis.

IPD Sharing Access Criteria

Access to trial IPD can be requested by qualified researchers engaging in independent scientific research, and will be provided following review and approval of a research proposal and Statistical Analysis Plan (SAP) and execution of a Data Sharing Agreement (DSA).

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • ICF

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

Yes

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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