Inspiratory Muscle Strength Training in Chronic Kidney Disease

Hypertension Clinical Trial

Official title:

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

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT04911491
• Other study ID #: 21-3000
• Secondary ID: R01DK130255
• Status: Recruiting
• Phase: N/A
• Start date: March 1, 2022
• Est. completion date: July 1, 2026

Study information

• Verified date: September 2023
• Source: University of Colorado, Denver
• Contact: Kristen Nowak, PhD, MPH
• Phone: 303-724-4842
• Email: Kristen.Nowak[@]cuanschutz.edu
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

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.

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.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 108
• Est. completion date: July 1, 2026
• Est. primary completion date: July 1, 2026
• Accepts healthy volunteers: No
• Gender: All
• Age group: 50 Years and older

Eligibility

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 (<5% weight change) and willing to remain weight stable throughout the study

• 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

Related Conditions & MeSH terms

• Aging
• Blood Pressure
• Chronic Kidney Diseases
• Hypertension
• Kidney Diseases
• Renal Insufficiency, Chronic

Intervention

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 Training
Repeated inhalations against a low resistance will be performed using a handheld device.

Locations

Country	Name	City	State
United States	University of Colorado - Anschutz Medical Campus	Aurora	Colorado

Sponsors (3)

Lead Sponsor	Collaborator
University of Colorado, Denver	National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), University of Colorado, Boulder

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	Change in Ex Vivo Nitric Oxide Production	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 DAF-FM diacetate to detect nitric oxide production production in response to acetylcholine.	Baseline, 3 months
Other	Change in Ex Vivo HUVEC eNOS Activation	Human umbilical vein 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
Other	Change in Ex Vivo Reactive Oxygen Species Production	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
Other	Change in Endothelial Cell Protein Expression of MnSOD	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
Other	Change in Endothelial Cell Protein Expression of NADPH oxidase	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
Other	Change in Endothelial Cell Abundance of Nitrotyrosine	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
Other	Change in Renal Blood Flow	Magnetic resonance imaging will be used to determine flow of the renal arteries.	Baseline, 3 months
Other	Adherence	Adherence will be evaluated as percent of completed training sessions at the required workload using data stored on the training device.	3 months
Other	Safety (adverse events)	Safety will be evaluated as the number of participants with treatment-related adverse events in each group.	3 months
Other	Tolerability (drop-out due to adverse events)	Tolerability will assessed as the rate at which enrolled subjects drop out due to adverse events.	3 months
Other	Change in Casual Diastolic Blood Pressure	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
Other	Change in 24-Hour Ambulatory Diastolic Blood Pressure	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
Other	Change in Endothelium-Independent Dilation	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
Primary	Change in Casual Systolic Blood Pressure	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	Change in 24-Hour Ambulatory Systolic Blood Pressure	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
Secondary	Change in Brachial Artery Flow-Mediated Dilation	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