An interventional study of High-Resistance Inspiratory Muscle Strength Training and Sham Inspiratory Muscle Strength Training in Type 1 Diabetes, sponsored by Florida State University. Not yet recruiting at 2 sites in United States. Open to participants aged 18 Years to 35 Years. Per ClinicalTrials.gov, last updated 2026-10-06.
Sponsored by Florida State University · Not applicable, Interventional, and Prevention
Adults with type 1 diabetes have elevated cardiovascular disease risk, and systolic blood pressure is a leading modifiable contributor to that risk. Aerobic exercise lowers blood pressure but poses time and glycemic-management barriers for people with type 1 diabetes. Inspiratory muscle strength training is a brief, home-based, device-based intervention that takes about five minutes per day and has lowered systolic blood pressure in other adult populations.
This pilot trial will test whether eight weeks of daily high-resistance inspiratory muscle strength training lowers blood pressure and improves vascular function in adults with type 1 diabetes. Participants will be randomized 2:1 to high-resistance or very-low-resistance sham training using a POWERbreathe K3 device and will complete 30 training breaths per day at home for eight weeks. Outcomes are assessed before and after the training period.
Approximately two million Americans live with type 1 diabetes, and cardiovascular disease is the leading cause of death in this population. After glycemic control, systolic blood pressure is the leading modifiable cardiovascular risk factor. Traditional aerobic exercise lowers blood pressure and improves vascular function, but most adults with type 1 diabetes do not meet physical activity recommendations, citing time constraints and concern about exercise-associated hypoglycemia.
Inspiratory muscle strength training (IMST) requires about five minutes per day, is performed seated at home with a commercially available handheld device, and is unlikely to provoke hypoglycemia. A retrospective analysis of five independent trials in 128 adults reported a 9 mmHg reduction in casual systolic blood pressure following high-resistance IMST compared with sham training, with effects that appear consistent across age, sex, health status, and baseline blood pressure. No study has examined IMST in people with type 1 diabetes.
Participants are randomized in a 2:1 ratio to high-resistance IMST or very-low-resistance sham IMST. Randomization uses a computer-generated sequence held by an unmasked team member who is responsible only for setting device resistance; participants, investigators, and outcome assessors remain masked to group assignment. All participants complete approximately 56 daily training sessions over eight weeks, each consisting of five bouts of six forceful inhalations with about 30 seconds of rest between bouts.
Maximal inspiratory pressure is measured at weeks 0, 2, 4, 6, and 8. For the high-resistance group, device resistance is set to a graded percentage of the participant's current maximal inspiratory pressure: 55% during weeks 1-2, 65% during weeks 3-4, and 75% during weeks 5-8. The sham group trains at 15% of maximal inspiratory pressure throughout. Participants are debriefed on their group assignment at the end of the post-training visit.
Testing visits at week 0 and week 8 include laboratory blood pressure, brachial artery flow-mediated dilation and post-occlusion reactive hyperemia by high-resolution ultrasound, central blood pressure and arterial stiffness by applanation tonometry, and isometric handgrip exercise testing with post-exercise circulatory occlusion. Participants measure their blood pressure at home once weekly on a provided automated monitor during weeks without a laboratory visit. Brief check-in contacts occur on odd weeks and device adjustment visits on even weeks. An optional follow-up visit repeating all assessments is offered at week 12.
3,522 studies on the registry are indexed under Diabetes Mellitus, Type 1; 577 are open to participants now.
This study's planned enrollment of 30 is below the median of 40 across 2,649 interventional studies indexed under Diabetes Mellitus, Type 1.
Browse Diabetes Mellitus, Type 1 studies →Florida State University is the lead sponsor of 241 studies on the registry; 46 are open to participants now.
Of its 15 completed or terminated interventional studies of FDA-regulated products, 9 (60%) have results posted.
Counted across the registry records on this site, refreshed daily.
Age 18 to 35 years Type 1 diabetes diagnosed more than 1 year before screening HbA1c 10.0% or less within the last 3 months (may be measured at screening) Body mass index 18 to 29.9 kg/m\^2 Stable insulin delivery method for the past 30 days Ability to read all device instructions and insulin pump settings Estimated glomerular filtration rate at least 60 mL/min/1.73 m\^2 within the last 3 months (may be measured at screening) Use of an insulin pump or insulin delivery by multiple daily injections Attendance at 3 or more diabetes care visits over the past 12 months
Exclusion Criteria:
Diabetes-related hospitalization, including for diabetic ketoacidosis or severe hypoglycemia, within 12 months of screening Poorly controlled hypertension, defined as systolic blood pressure at least 140 mmHg or diastolic blood pressure at least 90 mmHg Taking diabetes medications other than insulin Structured exercise more than 150 minutes per week for the last 3 months Pregnant, lactating, or planning to become pregnant within the study period Unstable weight, defined as more than 5% change in the last 3 months Significant organ system dysfunction, such as severe pulmonary, renal, hepatic, or cardiovascular disease Diagnosed anemia or known hemoglobin less than 10 g/dL Diagnosed neuropathic or psychiatric illness Active nicotine or illegal drug use Alcohol consumption totaling more than 10 standard drinks per week Unable to grant voluntary informed consent Unable or unwilling to follow the study protocol Per the POWERbreathe device user manual: history of spontaneous pneumothorax; a collapsed lung that has not fully healed; a pacemaker or medical implant containing magnets or electronics; any condition of the eardrum, such as a burst eardrum that has not fully healed
Participants complete daily inspiratory muscle strength training using a POWERbreathe K3 device for eight weeks. Each session consists of five bouts of six forceful inhalations against resistance, with approximately 30 seconds of rest between bouts, for 30 training breaths per day. Resistance is set to a graded percentage of the participant's current maximal inspiratory pressure: 55% during weeks 1-2, 65% during weeks 3-4, and 75% during weeks 5-8.
Device: High-Resistance Inspiratory Muscle Strength Training
Participants complete daily inspiratory muscle strength training using a POWERbreathe K3 device for eight weeks. Each session consists of five bouts of six forceful inhalations against resistance, with approximately 30 seconds of rest between bouts, for 30 training breaths per day. Resistance is set to 15% of the participant's maximal inspiratory pressure throughout the eight weeks.
Device: Sham Inspiratory Muscle Strength Training
Daily home-based inspiratory muscle strength training using a POWERbreathe K3 device for eight weeks, at 55% of maximal inspiratory pressure during weeks 1-2, 65% during weeks 3-4, and 75% during weeks 5-8. Maximal inspiratory pressure is re-measured at weeks 0, 2, 4, 6, and 8 and resistance is adjusted accordingly.
Daily home-based inspiratory muscle strength training using a POWERbreathe K3 device for eight weeks, at 15% of maximal inspiratory pressure throughout.
Change From Baseline in Laboratory-Measured Seated Systolic Blood Pressure at 8 Weeks
Seated brachial systolic blood pressure measured in the laboratory with an automated oscillometric monitor after a period of quiet rest. This is the powered primary outcome.
Time frame: Baseline and 8 weeks
Change From Baseline in Home Systolic Blood Pressure at 8 Weeks
Self-measured seated brachial systolic blood pressure recorded at home once weekly on a provided automated monitor, following American Heart Association home-monitoring recommendations.
Time frame: Baseline and 8 weeks
Plan to share: Yes — De-identified individual participant-level data (IPD) that correspond directly to the key outcomes reported in peer-reviewed publications will be preserved and shared.
Supporting information: Study protocol, Sap, Icf
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is not yet recruiting, as verified in Sep 2026. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Florida State University