Hypothyroidism PrimaryNCT07865975
The Effect of Respiratory Muscle Training on Respiratory Parameters
A study testing Progressive Muscle Training in people with Hypothyroidism Primary, run by Cyprus International University at 1 site in Turkey (Türkiye).
Trial summary
The goal of this randomized controlled study is to find out whether an eight-week respiratory muscle training program can improve breathing, respiratory muscle strength and endurance, physical capacity, body composition, fatigue, exercise-related beliefs and barriers, quality of life, and emotional well-being in… Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Hypothyroidism Primary
- What is being tested?
- Progressive Muscle Training
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 30 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 21 Jun 2023to 20 May 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Being 18 years of age or older,
- Having a diagnosis of primary hypothyroidism,
- Receiving standard thyroid hormone replacement therapy (levothyroxine) for at least the past three months.
Who cannot join
- Cardiovascular or respiratory diseases, chronic renal failure, diabetes mellitus (Type 1 or Type 2)
- Significant neurological or psychological disorders, communication barriers, or any physical or psychological impairment affecting mobility,
- Additionally, participants were excluded if they voluntarily requested to withdraw from the study at any point.
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Cyprus International University
Mersin, Lefkosa, 99040
About this study
Official title: The Effect of Respiratory Muscle Training on Respiratory Parameters, Respiratory Muscle Strength and Endurance, Functional Capacity and Emotional State in Hypothyroid Patients
The goal of this randomized controlled study is to find out whether an eight-week respiratory muscle training program can improve breathing, respiratory muscle strength and endurance, physical capacity, body composition, fatigue, exercise-related beliefs and barriers, quality of life, and emotional well-being in adults aged 18 years or older with hypothyroidism who have been taking levothyroxine for at least three months. The study asks whether participants who complete progressive inspiratory muscle training show greater improvement in these areas than participants who train at the device's lowest resistance. Women and men will be randomly assigned to one of the two groups. Both groups will perform breathing exercises at home five days a week for eight weeks, with the training group gradually increasing the exercise resistance. Participants will be assessed before and after the program using breathing and lung-function tests, physical-capacity and muscle-strength tests, body-composition measurements, and questionnaires.
Read the detailed description
Hypothyroidism is characterized by systemic metabolic slowing that frequently leads to respiratory muscle weakness, impaired ventilatory responses to hypoxia and hypercapnia, diaphragmatic dysfunction, and skeletal muscle myopathy. These physiological impairments often manifest clinically as exertional dyspnea, heightened fatigue, reduced functional exercise tolerance, altered body composition, and psychological vulnerabilities such as anxiety and depressive symptoms. Despite the prevalence of cardiorespiratory and neuromuscular complications in patients with thyroid dysfunction, targeted rehabilitative interventions addressing respiratory muscle performance remain largely unexplored in this clinical population. This randomized controlled trial evaluates the physiological, physical, and psychological impacts of structured inspiratory muscle training (IMT) using a targeted threshold loading device (IMT/PEP, GH Innotek) in medically managed hypothyroid patients. Following baseline screening and stratified randomization, participants are allocated into either an active progressive IMT intervention group or a low-intensity sham-control group for an eight-week intervention period. The active intervention involves progressive inspiratory threshold loading conducted five days per week across two daily sessions of 30 breaths each, blending supervised clinical sessions with monitored home-based training. Loading intensity starts at 30% of maximal inspiratory pressure (MIP) during the initial week, advancing to 50% across weeks 2 to 5, and reaching 70% of MIP throughout weeks 6 to 8. The control arm performs breathing exercises with the same device set to its minimum fixed resistance without progression for an equivalent duration. Comprehensive multi-system evaluations are conducted at baseline and upon completion of the eight-week program at Eastern Mediterranean University, Faculty of Health Sciences, Cardiopulmonary Exercise Unit. Assessments encompass pulmonary mechanics via standard spirometric and lung volume determinations, respiratory muscle performance through maximal inspiratory/expiratory pressures and maximal voluntary ventilation, peripheral muscle strength via digital back/leg and handgrip dynamometry, functional exercise performance through the standardized six-minute walk test with continuous hemodynamic and desaturation monitoring, bioelectrical impedance-derived body composition metrics, and validated patient-reported outcome measures evaluating multidimensional fatigue, exercise barriers, health perceptions, and emotional status.
- Conditions
- Hypothyroidism Primary
- Being tested
- Progressive Muscle Training, Control Group
- Keywords
- inspiratory muscle training, inspiratory muscle weakness, functional capacity, emotional state, hypothyroidism
- Medical subject headings
- Hypothyroidism
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Progressive Muscle TrainingOther
At this point, the significance of specific rehabilitation approaches added to medical therapy, particularly structured inspiratory muscle training (IMT), becomes evident. Strong evidence in the literature demonstrates that IMT increases the proportion of Type 1 muscle fibers and induces structural hypertrophy in the diaphragm by improving oxidative capacity in other systemic diseases that increase respiratory workload, such as Chronic Obstructive Pulmonary Disease (COPD) and chronic heart failure. Considering that the diaphragmatic myopathy observed in hypothyroidism shares similar pathophysiological and cellular weaknesses, specific Respiratory Muscle Training (RMT) has a high potential to not only provide symptomatic relief but also improve mechanical function by triggering repair at the cellular level in this patient group.
Control GroupOther
To induce a placebo effect, the control group received sham training using the lowest possible resistance setting of the device (9 cmH₂O) for the full eight weeks, with no increments in training intensity.
| Study group | Role | What they receive |
|---|---|---|
| Inspiratory Muscle Training Group | Experimental | The training protocol was administered using the Philips Respironics®️ Threshold IMT device for both groups. The regimen was scheduled for seven days a week, consisting of one session per day (approximately 20 minutes). To enhance treatment adherence, three of the weekly sessions were supervised, while the remaining four were conducted as a home-based program monitored via telephone follow-ups. Each exercise session was structured as three sets of 30 repetitions, with one-minute rest intervals between the sets.
In the study group, training intensity was set at 40% of the individual's maximal inspiratory pressure (PImax). To ensure progressive loading, this PImax value was re-evaluated and adjusted every two weeks throughout the entire training process. Receives: Other: Progressive Muscle Training |
| Control Group | Sham comparator | To induce a placebo effect, the control group received sham training using the lowest possible resistance setting of the device (9 cmH₂O) for the full eight weeks, with no increments in training intensity. Receives: Other: Control Group |
What is being measured
The primary outcome is the main question the study is designed to answer.
Respiratory Muscle Strength
Respiratory muscle strength was evaluated using an electronic mouth pressure meter (MicroMPM, Micro Medical Ltd., UK). Measurements were performed in accordance with the American Thoracic Society (ATS) and European Respiratory Society (ERS) criteria. Maximal inspiratory pressure (PImax) was assessed following a maximal expiration to residual volume, whereupon the airway was occluded by a valve, and the participant performed a rapid, maximal inspiratory effort (Müller maneuver) sustained for 1-3 seconds. Conversely, maximal expiratory pressure (PEmax) was measured following a maximal inspiration to total lung capacity, where the participant performed a rapid, maximal expiratory effort (Valsalva maneuver) against an occluded airway for 1-3 seconds. Three measurements were obtained for each maneuver, and the highest value was recorded in cmH₂O.
Measured: From enrollment to the end of treatment at 8 weeks
Respiratory Muscle Endurance
Maximum voluntary ventilation (MVV) was measured using the direct method to assess respiratory muscle endurance. Participants were instructed to breathe as deeply and rapidly as possible for 15 seconds, and the recorded volume was subsequently multiplied by four to extrapolate the value to one minute. The normative values for MVV are typically 140-180 L/min for healthy individuals, and 80-120 L/min for females. Additionally, the predicted values calculated based on the variables of age, gender, and height were documented.
Measured: From enrollment to the end of treatment at 8 weeks
Pulmonary Function Parameters
Pulmonary functions were evaluated via spirometry. Spirometric measurements were conducted in a seated position using a nose clip, strictly adhering to ERS guidelines. Forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and inspiratory capacity (IC) were measured using a spirometer (SensorMedics™️ Vmax spectra 229, Bilthoven, The Netherlands). Participants performed three acceptable maneuvers, ensuring a variation of less than 5% between the efforts, and the highest values were recorded as the final result. The ERS reference equations were used to determine the predicted values.
Measured: From enrollment to the end of treatment at 8 weeks
Functional Capacity
Functional capacity will be assessed using the 6-Minute Walk Test (6MWT). Participants will be instructed to walk as far as possible for six minutes along a flat corridor at least 30 meters long. The total distance walked will be recorded in meters.
Measured: From enrollment to the end of treatment at 8 weeks
Dyspnea and Fatigue Assessment
Dyspnea and fatigue will be assessed immediately before and after the 6MWT using the modified Borg scale. Changes in dyspnea and fatigue scores from pre-test to post-test will be recorded separately.
Measured: From enrollment to the end of treatment at 8 weeks
Secondary outcomes (6)
Depression
Participants' depressive symptoms will be assessed using the Beck Depression Inventory, a self-report questionnaire designed to measure the severity of depressive symptoms in adults. Higher scores indicate greater symptom severity.
Measured: From enrollment to the end of treatment at 8 weeks
Anxiety
Participants' anxiety symptoms will be assessed using the Beck Anxiety Inventory, a 21-item self-report questionnaire. Each item is scored from 0 to 3, with higher total scores indicating greater anxiety symptom severity.
Measured: From enrollment to the end of treatment at 8 weeks
Exercise Beliefs
Participants' exercise beliefs will be assessed using a 33-item questionnaire with three subscales: perceived advantages, affected individuals, and perceived disadvantages. Items are rated on a 6-point scale from 1 ("strongly disagree") to 6 ("strongly agree"). Higher scores indicate more positive exercise beliefs.
Measured: From enrollment to the end of treatment at 8 weeks
Fatigue
Fatigue will be assessed using the Fatigue Impact Scale, a 40-item questionnaire covering the physical, cognitive, and social effects of fatigue. Each item is scored from 1 to 4, with total scores ranging from 40 to 160; higher scores indicate a greater impact of fatigue.
Measured: From enrollment to the end of treatment at 8 weeks
Sleep Quality
Sleep quality will be assessed using the Pittsburgh Sleep Quality Index (PSQI), which evaluates seven components: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleep medication, and daytime dysfunction. The total score ranges from 0 to 21, with higher scores indicating poorer sleep quality; scores above 5 indicate poor sleep quality.
Measured: From enrollment to the end of treatment at 8 weeks
Quality of Life
Quality of life will be assessed using the Short Form-36 (SF-36), a 36-item questionnaire covering eight domains: physical functioning, role limitations due to physical health, role limitations due to emotional problems, bodily pain, vitality, social functioning, mental health, and general health. Each domain is scored from 0 to 100, with higher scores indicating better quality of life.
Measured: From enrollment to the end of treatment at 8 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted8 Oct 2026
- Study start21 Jun 2023
- Primary completion13 Feb 2026
- Study completion20 May 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (8)Papers the sponsor has linked to this study.
- Other trials for Hypothyroidism PrimaryStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- Randomized Controlled Study
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 30 participants (actual)
Sponsor and investigators
- Lead sponsor
- Cyprus International University
- Sponsor type
- University, hospital or other
- Collaborators
- Eastern Mediterranean University
- Responsible party
- Sponsor
- Investigators
- Mehtap Malkoc, Prof. Dr., Study chair, Eastern Mediterranean UniversityAyse Volkan, MSc., Principal investigator, Cyprus International University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07865975
- Sponsor's protocol ID
- ETK00-2023-0132
- Status last verified
- Oct 2026
- First submitted
- 30 Sep 2026
- Last updated
- 8 Oct 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Individual participant data that underlie the results reported in this study-including de-identified sociodemographic and clinical characteristics, body composition metrics, and pre- and post-intervention scores for respiratory parameters (spirometry and lung volumes), respiratory and peripheral muscle strength, respiratory muscle endurance, functional exercise capacity (6MWT), fatigue (FIS), psychological status (BDI, BAI), and exercise beliefs-will be shared.
Publications
Green ME, Bernet V, Cheung J. Thyroid Dysfunction and Sleep Disorders. Front Endocrinol (Lausanne). 2021 Aug 24;12:725829. doi: 10.3389/fendo.2021.725829. eCollection 2021.
PubMed 34504473Mohammed RN, Kadhum HJ, Hashim AR. Spirometry in adult hypothyroid patients: a comparative study. J Basic Clin Physiol Pharmacol. 2020 Nov 13;32(3):189-195. doi: 10.1515/jbcpp-2019-0359.
PubMed 33180033Weiner M, Chausow A, Szidon P. Reversible respiratory muscle weakness in hypothyroidism. Br J Dis Chest. 1986 Oct;80(4):391-5. doi: 10.1016/0007-0971(86)90093-8.
PubMed 3620325Terzano C, Romani S, Paone G, Conti V, Oriolo F. COPD and thyroid dysfunctions. Lung. 2014 Feb;192(1):103-9. doi: 10.1007/s00408-013-9537-6. Epub 2013 Nov 27.
PubMed 24281671Sorensen JR, Winther KH, Bonnema SJ, Godballe C, Hegedus L. Respiratory Manifestations of Hypothyroidism: A Systematic Review. Thyroid. 2016 Nov;26(11):1519-1527. doi: 10.1089/thy.2015.0642.
PubMed 27673426Saad NS, Mashali MA, Elnakish MT, Hare A, Campbell CM, Kiduko SA, Peczkowski KK, Huang AW, Fazlollahi F, Torres Matias GS, Ahmed AAE, Whitson BA, Mokadam NA, Janssen PML. Effect of hypothyroidism on contractile performance of isolated end-stage failing human myocardium. PLoS One. 2022 Apr 11;17(4):e0265731. doi: 10.1371/journal.pone.0265731. eCollection 2022.
PubMed 35404981Ringel MD, Sosa JA, Baloch Z, Bischoff L, Bloom G, Brent GA, Brock PL, Chou R, Flavell RR, Goldner W, Grubbs EG, Haymart M, Larson SM, Leung AM, Osborne JR, Ridge JA, Robinson B, Steward DL, Tufano RP, Wirth LJ. 2025 American Thyroid Association Management Guidelines for Adult Patients with Differentiated Thyroid Cancer. Thyroid. 2025 Aug;35(8):841-985. doi: 10.1177/10507256251363120.
PubMed 40844370Pancholi C, Chaudhary SC, Gupta KK, Sawlani KK, Verma SK, Singh A, Verma AK, Usman K, Atam V. Obstructive sleep apnea in hypothyroidism. Ann Afr Med. 2022 Oct-Dec;21(4):403-409. doi: 10.4103/aam.aam_134_21.
PubMed 36412342
Study at a glance
From the registry record, last updated by the sponsor on 8 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect of Respiratory Muscle Training on Respiratory Parameters, Respiratory Muscle Strength and Endurance, Functional Capacity and Emotional State in Hypothyroid Patients
- ClinicalTrials.gov ID
- NCT07865975
- Acronym / sponsor ID
- ETK00-2023-0132
- Conditions
- Hypothyroidism Primary
- Keywords
- inspiratory muscle training, inspiratory muscle weakness, functional capacity, emotional state, hypothyroidism
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 30 participants (actual)
- Lead sponsor
- Cyprus International UniversityUniversity, hospital or other
- Collaborators
- Eastern Mediterranean University
- Study start
- 21 Jun 2023 (actual)
- Primary completion
- 13 Feb 2026 (actual)
- Study completion
- 20 May 2026 (actual)
- First posted
- 8 Oct 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this randomized controlled study is to find out whether an eight-week respiratory muscle training program can improve breathing, respiratory muscle strength and endurance, physical capacity, body composition, fatigue, exercise-related beliefs and barriers, quality of life, and emotional well-being in adults aged 18 years or older with hypothyroidism who have been taking levothyroxine for at least three months. The study asks whether participants who complete progressive inspiratory muscle training show greater improvement in these areas than participants who train at the device's lowest resistance. Women and men will be randomly assigned to one of the two groups. Both groups will perform breathing exercises at home five days a week for eight weeks, with the training group gradually increasing the exercise resistance. Participants will be assessed before and after the program using breathing and lung-function tests, physical-capacity and muscle-strength tests, body-composition measurements, and questionnaires.
Detailed description
Hypothyroidism is characterized by systemic metabolic slowing that frequently leads to respiratory muscle weakness, impaired ventilatory responses to hypoxia and hypercapnia, diaphragmatic dysfunction, and skeletal muscle myopathy. These physiological impairments often manifest clinically as exertional dyspnea, heightened fatigue, reduced functional exercise tolerance, altered body composition, and psychological vulnerabilities such as anxiety and depressive symptoms. Despite the prevalence of cardiorespiratory and neuromuscular complications in patients with thyroid dysfunction, targeted rehabilitative interventions addressing respiratory muscle performance remain largely unexplored in this clinical population. This randomized controlled trial evaluates the physiological, physical, and psychological impacts of structured inspiratory muscle training (IMT) using a targeted threshold loading device (IMT/PEP, GH Innotek) in medically managed hypothyroid patients. Following baseline screening and stratified randomization, participants are allocated into either an active progressive IMT intervention group or a low-intensity sham-control group for an eight-week intervention period. The active intervention involves progressive inspiratory threshold loading conducted five days per week across two daily sessions of 30 breaths each, blending supervised clinical sessions with monitored home-based training. Loading intensity starts at 30% of maximal inspiratory pressure (MIP) during the initial week, advancing to 50% across weeks 2 to 5, and reaching 70% of MIP throughout weeks 6 to 8. The control arm performs breathing exercises with the same device set to its minimum fixed resistance without progression for an equivalent duration. Comprehensive multi-system evaluations are conducted at baseline and upon completion of the eight-week program at Eastern Mediterranean University, Faculty of Health Sciences, Cardiopulmonary Exercise Unit. Assessments encompass pulmonary mechanics via standard spirometric and lung volume determinations, respiratory muscle performance through maximal inspiratory/expiratory pressures and maximal voluntary ventilation, peripheral muscle strength via digital back/leg and handgrip dynamometry, functional exercise performance through the standardized six-minute walk test with continuous hemodynamic and desaturation monitoring, bioelectrical impedance-derived body composition metrics, and validated patient-reported outcome measures evaluating multidimensional fatigue, exercise barriers, health perceptions, and emotional status.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
- Model description
- Randomized Controlled Study
| Arm | Type | Receives |
|---|---|---|
| Inspiratory Muscle Training Group | Experimental | Other: Progressive Muscle TrainingThe training protocol was administered using the Philips Respironics®️ Threshold IMT device for both groups. The regimen was scheduled for seven days a week, consisting of one session per day (approximately 20 minutes). To enhance treatment adherence, three of the weekly sessions were supervised, while the remaining four were conducted as a home-based program monitored via telephone follow-ups. Each exercise session was structured as three sets of 30 repetitions, with one-minute rest intervals between the sets. In the study group, training intensity was set at 40% of the individual's maximal inspiratory pressure (PImax). To ensure progressive loading, this PImax value was re-evaluated and adjusted every two weeks throughout the entire training process. |
| Control Group | Sham comparator | Other: Control GroupTo induce a placebo effect, the control group received sham training using the lowest possible resistance setting of the device (9 cmH₂O) for the full eight weeks, with no increments in training intensity. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Being 18 years of age or older,
- Having a diagnosis of primary hypothyroidism,
- Receiving standard thyroid hormone replacement therapy (levothyroxine) for at least the past three months.
Key exclusion criteria (3 listed)
- Cardiovascular or respiratory diseases, chronic renal failure, diabetes mellitus (Type 1 or Type 2)
- Significant neurological or psychological disorders, communication barriers, or any physical or psychological impairment affecting mobility,
- Additionally, participants were excluded if they voluntarily requested to withdraw from the study at any point.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Progressive Muscle TrainingAt this point, the significance of specific rehabilitation approaches added to medical therapy, particularly structured inspiratory muscle training (IMT), becomes evident. Strong evidence in the literature demonstrates that IMT increases the proportion of Type 1 muscle fibers and induces structural hypertrophy in the diaphragm by improving oxidative capacity in other systemic diseases that increase respiratory workload, such as Chronic Obstructive Pulmonary Disease (COPD) and chronic heart failure. Considering that the diaphragmatic myopathy observed in hypothyroidism shares similar pathophysiological and cellular weaknesses, specific Respiratory Muscle Training (RMT) has a high potential to not only provide symptomatic relief but also improve mechanical function by triggering repair at the cellular level in this patient group. | Other | Inspiratory Muscle Training Group |
| Control GroupTo induce a placebo effect, the control group received sham training using the lowest possible resistance setting of the device (9 cmH₂O) for the full eight weeks, with no increments in training intensity. | Other | Control Group |
Primary outcome
Respiratory Muscle Strength
Time frame: From enrollment to the end of treatment at 8 weeks
Respiratory muscle strength was evaluated using an electronic mouth pressure meter (MicroMPM, Micro Medical Ltd., UK). Measurements were performed in accordance with the American Thoracic Society (ATS) and European Respiratory Society (ERS) criteria. Maximal inspiratory pressure (PImax) was assessed following a maximal expiration to residual volume, whereupon the airway was occluded by a valve, and the participant performed a rapid, maximal inspiratory effort (Müller maneuver) sustained for 1-3 seconds. Conversely, maximal expiratory pressure (PEmax) was measured following a maximal inspiration to total lung capacity, where the participant performed a rapid, maximal expiratory effort (Valsalva maneuver) against an occluded airway for 1-3 seconds. Three measurements were obtained for each maneuver, and the highest value was recorded in cmH₂O.
Respiratory Muscle Endurance
Time frame: From enrollment to the end of treatment at 8 weeks
Maximum voluntary ventilation (MVV) was measured using the direct method to assess respiratory muscle endurance. Participants were instructed to breathe as deeply and rapidly as possible for 15 seconds, and the recorded volume was subsequently multiplied by four to extrapolate the value to one minute. The normative values for MVV are typically 140-180 L/min for healthy individuals, and 80-120 L/min for females. Additionally, the predicted values calculated based on the variables of age, gender, and height were documented.
Pulmonary Function Parameters
Time frame: From enrollment to the end of treatment at 8 weeks
Pulmonary functions were evaluated via spirometry. Spirometric measurements were conducted in a seated position using a nose clip, strictly adhering to ERS guidelines. Forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and inspiratory capacity (IC) were measured using a spirometer (SensorMedics™️ Vmax spectra 229, Bilthoven, The Netherlands). Participants performed three acceptable maneuvers, ensuring a variation of less than 5% between the efforts, and the highest values were recorded as the final result. The ERS reference equations were used to determine the predicted values.
Functional Capacity
Time frame: From enrollment to the end of treatment at 8 weeks
Functional capacity will be assessed using the 6-Minute Walk Test (6MWT). Participants will be instructed to walk as far as possible for six minutes along a flat corridor at least 30 meters long. The total distance walked will be recorded in meters.
Dyspnea and Fatigue Assessment
Time frame: From enrollment to the end of treatment at 8 weeks
Dyspnea and fatigue will be assessed immediately before and after the 6MWT using the modified Borg scale. Changes in dyspnea and fatigue scores from pre-test to post-test will be recorded separately.
6 secondary outcomes
Depression
Time frame: From enrollment to the end of treatment at 8 weeks
Anxiety
Time frame: From enrollment to the end of treatment at 8 weeks
Exercise Beliefs
Time frame: From enrollment to the end of treatment at 8 weeks
Fatigue
Time frame: From enrollment to the end of treatment at 8 weeks
Sleep Quality
Time frame: From enrollment to the end of treatment at 8 weeks
Quality of Life
Time frame: From enrollment to the end of treatment at 8 weeks
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 8 Oct 2026.
- Results publication: PubMed 34504473Green ME, Bernet V, Cheung J. Thyroid Dysfunction and Sleep Disorders. Front Endocrinol (Lausanne). 2021 Aug 24;12:725829. doi: 10.3389/fendo.2021.725829. eCollection 2021.
- Results publication: PubMed 33180033Mohammed RN, Kadhum HJ, Hashim AR. Spirometry in adult hypothyroid patients: a comparative study. J Basic Clin Physiol Pharmacol. 2020 Nov 13;32(3):189-195. doi: 10.1515/jbcpp-2019-0359.
- Results publication: PubMed 3620325Weiner M, Chausow A, Szidon P. Reversible respiratory muscle weakness in hypothyroidism. Br J Dis Chest. 1986 Oct;80(4):391-5. doi: 10.1016/0007-0971(86)90093-8.
- Results publication: PubMed 24281671Terzano C, Romani S, Paone G, Conti V, Oriolo F. COPD and thyroid dysfunctions. Lung. 2014 Feb;192(1):103-9. doi: 10.1007/s00408-013-9537-6. Epub 2013 Nov 27.
- Results publication: PubMed 27673426Sorensen JR, Winther KH, Bonnema SJ, Godballe C, Hegedus L. Respiratory Manifestations of Hypothyroidism: A Systematic Review. Thyroid. 2016 Nov;26(11):1519-1527. doi: 10.1089/thy.2015.0642.
- Results publication: PubMed 35404981Saad NS, Mashali MA, Elnakish MT, Hare A, Campbell CM, Kiduko SA, Peczkowski KK, Huang AW, Fazlollahi F, Torres Matias GS, Ahmed AAE, Whitson BA, Mokadam NA, Janssen PML. Effect of hypothyroidism on contractile performance of isolated end-stage failing human myocardium. PLoS One. 2022 Apr 11;17(4):e0265731. doi: 10.1371/journal.pone.0265731. eCollection 2022.
- Results publication: PubMed 40844370Ringel MD, Sosa JA, Baloch Z, Bischoff L, Bloom G, Brent GA, Brock PL, Chou R, Flavell RR, Goldner W, Grubbs EG, Haymart M, Larson SM, Leung AM, Osborne JR, Ridge JA, Robinson B, Steward DL, Tufano RP, Wirth LJ. 2025 American Thyroid Association Management Guidelines for Adult Patients with Differentiated Thyroid Cancer. Thyroid. 2025 Aug;35(8):841-985. doi: 10.1177/10507256251363120.
- Results publication: PubMed 36412342Pancholi C, Chaudhary SC, Gupta KK, Sawlani KK, Verma SK, Singh A, Verma AK, Usman K, Atam V. Obstructive sleep apnea in hypothyroidism. Ann Afr Med. 2022 Oct-Dec;21(4):403-409. doi: 10.4103/aam.aam_134_21.
- Individual participant dataSharing planned: Yes. Individual participant data that underlie the results reported in this study-including de-identified sociodemographic and clinical characteristics, body composition metrics, and pre- and post-intervention scores for respiratory parameters (spirometry and lung volumes), respiratory and peripheral muscle strength, respiratory muscle endurance, functional exercise capacity (6MWT), fatigue (FIS), psychological status (BDI, BAI), and exercise beliefs-will be shared.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Mehtap Malkoc, Prof. Dr. study chair
Eastern Mediterranean University
Ayse Volkan, MSc. principal investigator
Cyprus International University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Progressive Muscle Training in people with Hypothyroidism Primary, run by Cyprus International University at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 8 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Respiratory Muscle Strength (time frame: From enrollment to the end of treatment at 8 weeks). The study lists 5 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07865975, which also lists 8 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 8 Oct 2026.