Type 1 Diabetes (T1D)NCT06935903
Marathon Runners With Type 1 Diabetes
An observational study of Type 1 Diabetes (T1D), run by Poznan University of Medical Sciences at 1 site in Poland.
Trial summary
The goal of this observational study is to learn about the physical capacity and metabolic characteristics of male marathon runners with type 1 diabetes mellitus (T1DM). The main question it aims to answer is: Do male marathon runners with T1DM have different physical fitness and metabolic profiles compared to healthy… Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Type 1 Diabetes (T1D)
- How many people
- 10 participants
- Where
- 1 sitePoland
- Study dates
- 30 Aug 2023to 22 Oct 2023
- Phase
- Observational
- 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
Study population: Adult marathon runners aged ≥18 years. Participants in the T1DM group with a confirmed diagnosis of T1DM for at least one year. The control group comprises healthy people with similar physical activity levels but no chronic health conditions.
Who may be able to join
- A diagnosis of T1DM for at least 1 year.
- Age ≥ 18 years.
- Written informed consent and adherence to the study protocol.
Who cannot join
- Pregnancy.
- Use of medications significantly affecting metabolism or exercise performance
- Presence of chronic medical or psychiatric conditions limiting safe participation
- •Presence of advanced chronic complications of diabetes: proliferative retinopathy, diabetic kidney disease in stages III-V, cardiovascular diseases
- Inability to safely complete maximal exercise testing.
Trial locations and contacts
1 site in 1 country.
Poland1 site
Department of Internal Medicine and Diabetology, Poznan University of Medical Sciences
Poznan, Greater Poland Voivodeship, 60-834
About this study
Official title: Assessment of Physical Capacity and Metabolic Parameters in Marathon Runners With Type 1 Diabetes: an Observational Study
The goal of this observational study is to learn about the physical capacity and metabolic characteristics of male marathon runners with type 1 diabetes mellitus (T1DM). The main question it aims to answer is:
Do male marathon runners with T1DM have different physical fitness and metabolic profiles compared to healthy runners without diabetes?
Participants with T1DM and healthy controls who have completed a marathon will undergo a single in-person assessment, including body composition analysis, resting metabolic rate measurement, and a maximal exercise test
Read the detailed description
This observational, cross-sectional case-control study aims to compare physical capacity and metabolic parameters between male marathon runners with type 1 diabetes mellitus (T1DM) and healthy male marathon runners without diabetes. The study focuses on evaluating differences in cardiopulmonary fitness, resting metabolic rate, and body composition between the two groups.
Participants attended a single study visit after overnight fasting. The visit included anthropometric measurements, assessment of medical history, and structured questionnaires on diabetes management (for T1DM participants) and physical activity habits. Body composition was assessed using dual-energy X-ray absorptiometry (DXA), providing detailed analysis of total and regional fat mass, lean tissue mass, and bone mineral density. Daily calibration of the DXA scanner ensured data accuracy and consistency.
Resting metabolic rate (RMR) was measured by indirect calorimetry using a ventilated hood system. Measurements were performed in a controlled environment with standardized temperature and low light to minimize variability. Data collection spanned 25 minutes, with the first 5 minutes discarded for acclimatization and the subsequent 20 minutes analyzed. Energy expenditure and substrate oxidation rates were calculated using established equations (Weir equation and Zuntz table).
Cardiorespiratory fitness was assessed through a maximal exercise test on a cycle ergometer with continuous respiratory gas analysis. The test protocol began with a resting phase and warm-up, followed by incremental workload increases until volitional exhaustion. Parameters such as VO₂max, ventilatory efficiency, gas exchange threshold, and peak workload were measured using a calibrated metabolic cart.
Data analysis involved descriptive statistics, Mann-Whitney U tests for numerical comparisons, and Chi-square tests for categorical variables. Dedicated manufacturer software was used for CPET data processing, and statistical analyses were conducted using R software (version 4.4.1).
- Conditions
- Type 1 Diabetes (T1D)
- Keywords
- Type 1 Diabetes, Physical Activity, Physical Endurance, Absorptiometry, Oxygen Consumption
- Medical subject headings
- Diabetes Mellitus, Type 1, Motor Activity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Type 1 diabetes group | Male participants with confirmed T1DM diagnosis for ≥1 year who have completed a marathon. | |
| Control Group | Healthy male marathon runners matched by age, sex, and training background |
What is being measured
The primary outcome is the main question the study is designed to answer.
VO₂max (mL/kg/min)
peak oxygen uptake during graded exercise testing
Measured: single visit
Secondary outcomes (6)
Resting metabolic rate (kcal/day)
The amount of energy expended by the body at rest in a fasting state, measured in kilocalories per day using indirect calorimetry.
Measured: single visit
Body adipose percentage [%]
The proportion of a person's total body mass that is composed of adipose tissue, assessed using dual-energy X-ray absorptiometry (DXA).
Measured: single visit
Lean tissue percentage [%]
The proportion of a person's total body mass that is composed of lean tissue, assessed using dual-energy X-ray absorptiometry (DXA).
Measured: single visit
Forced Vital Capacity [L]
the total volume of air exhaled forcefully after a full inhalation, measured in liters.
Measured: single visit
Maximum Vital Capacity [L]
the greatest volume of air that can be exhaled after a maximal inhalation, measured in liters.
Measured: single visit
Forced Expiratory Volume in 1 second [%]
the percentage of the Forced Vital Capacity that is exhaled during the first second of a forced breath, indicating airway function
Measured: single visit
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted20 Apr 2025
- Study start30 Aug 2023
- Primary completion22 Oct 2023
- Study completion22 Oct 2023
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 Type 1 Diabetes (T1D)Studies 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
- Observational
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Enrolment
- 10 participants (actual)
Sponsor and investigators
- Lead sponsor
- Poznan University of Medical Sciences
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Zozulińska-Ziółkiewicz Dorota MD PhD, Poznan University of Medical Sciences
- Investigators
- Dorota Zozulinska-Ziolkiewicz, MD, PhD, Principal investigator, Department of Internal Medicine and Diabetology, Poznan University of Medical Sciences
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06935903
- Sponsor's protocol ID
- NdS/544750/2021/2022
- Other IDs
- 1245/18
- Status last verified
- Apr 2025
- First submitted
- 13 Apr 2025
- Last updated
- 20 Apr 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: IPD will not be shared due to the small sample size and the potential risk of participant re-identification, even with de-identified data. The study was not designed with broad data sharing in mind, and no participant consent was obtained for public data release.
Publications
Shepherd JA, Ng BK, Sommer MJ, Heymsfield SB. Body composition by DXA. Bone. 2017 Nov;104:101-105. doi: 10.1016/j.bone.2017.06.010. Epub 2017 Jun 16.
PubMed 28625918Achamrah N, Delsoglio M, De Waele E, Berger MM, Pichard C. Indirect calorimetry: The 6 main issues. Clin Nutr. 2021 Jan;40(1):4-14. doi: 10.1016/j.clnu.2020.06.024. Epub 2020 Jul 2.
PubMed 32709554Poole DC, Wilkerson DP, Jones AM. Validity of criteria for establishing maximal O2 uptake during ramp exercise tests. Eur J Appl Physiol. 2008 Mar;102(4):403-10. doi: 10.1007/s00421-007-0596-3. Epub 2007 Oct 30.
PubMed 17968581Thuillier P, Domun N, Sonnet E, Le Ven F, Roudaut C, Kergus A, Kerlan V, Roudaut N. Prevention of exercise-induced hypoglycemia in 12 patients with type 1 diabetes running the Paris Marathon using continuous glucose monitoring: A prospective, single-center observational study. Diabetes Metab. 2022 Mar;48(2):101321. doi: 10.1016/j.diabet.2022.101321. Epub 2022 Jan 12.
PubMed 35032674Grimm JJ, Muchnick S. Type I diabetes and marathon running. Diabetes Care. 1993 Dec;16(12):1624. doi: 10.2337/diacare.16.12.1624a. No abstract available.
PubMed 8299461Riddell MC, Scott SN, Fournier PA, Colberg SR, Gallen IW, Moser O, Stettler C, Yardley JE, Zaharieva DP, Adolfsson P, Bracken RM. The competitive athlete with type 1 diabetes. Diabetologia. 2020 Aug;63(8):1475-1490. doi: 10.1007/s00125-020-05183-8. Epub 2020 Jun 12.
PubMed 32533229Chimen M, Kennedy A, Nirantharakumar K, Pang TT, Andrews R, Narendran P. What are the health benefits of physical activity in type 1 diabetes mellitus? A literature review. Diabetologia. 2012 Mar;55(3):542-51. doi: 10.1007/s00125-011-2403-2. Epub 2011 Dec 22.
PubMed 22189486Kulecki M, Daroszewski M, Birula P, Kreczmer A, Pietrzak M, Adamska A, Michalak M, Bonikowska A, Sroczynska A, Michalski M, Zozulinska-Ziolkiewicz D, Gawrecki A. Assessment of cardiorespiratory fitness and body composition in marathon runners with type 1 diabetes: an observational study. BMC Sports Sci Med Rehabil. 2025 Nov 3;17(1):317. doi: 10.1186/s13102-025-01303-2.
PubMed 41184866
Study at a glance
From the registry record, last updated by the sponsor on 20 Apr 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Assessment of Physical Capacity and Metabolic Parameters in Marathon Runners With Type 1 Diabetes: an Observational Study
- ClinicalTrials.gov ID
- NCT06935903
- Acronym / sponsor ID
- NdS/544750/2021/2022
- Conditions
- Type 1 Diabetes (T1D)
- Keywords
- Type 1 Diabetes, Physical Activity, Physical Endurance, Absorptiometry, Oxygen Consumption
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 10 participants (actual)
- Lead sponsor
- Poznan University of Medical SciencesUniversity, hospital or other
- Study start
- 30 Aug 2023 (actual)
- Primary completion
- 22 Oct 2023 (actual)
- Study completion
- 22 Oct 2023 (actual)
- First posted
- 20 Apr 2025 (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 observational study is to learn about the physical capacity and metabolic characteristics of male marathon runners with type 1 diabetes mellitus (T1DM). The main question it aims to answer is:
Do male marathon runners with T1DM have different physical fitness and metabolic profiles compared to healthy runners without diabetes?
Participants with T1DM and healthy controls who have completed a marathon will undergo a single in-person assessment, including body composition analysis, resting metabolic rate measurement, and a maximal exercise test
Detailed description
This observational, cross-sectional case-control study aims to compare physical capacity and metabolic parameters between male marathon runners with type 1 diabetes mellitus (T1DM) and healthy male marathon runners without diabetes. The study focuses on evaluating differences in cardiopulmonary fitness, resting metabolic rate, and body composition between the two groups.
Participants attended a single study visit after overnight fasting. The visit included anthropometric measurements, assessment of medical history, and structured questionnaires on diabetes management (for T1DM participants) and physical activity habits. Body composition was assessed using dual-energy X-ray absorptiometry (DXA), providing detailed analysis of total and regional fat mass, lean tissue mass, and bone mineral density. Daily calibration of the DXA scanner ensured data accuracy and consistency.
Resting metabolic rate (RMR) was measured by indirect calorimetry using a ventilated hood system. Measurements were performed in a controlled environment with standardized temperature and low light to minimize variability. Data collection spanned 25 minutes, with the first 5 minutes discarded for acclimatization and the subsequent 20 minutes analyzed. Energy expenditure and substrate oxidation rates were calculated using established equations (Weir equation and Zuntz table).
Cardiorespiratory fitness was assessed through a maximal exercise test on a cycle ergometer with continuous respiratory gas analysis. The test protocol began with a resting phase and warm-up, followed by incremental workload increases until volitional exhaustion. Parameters such as VO₂max, ventilatory efficiency, gas exchange threshold, and peak workload were measured using a calibrated metabolic cart.
Data analysis involved descriptive statistics, Mann-Whitney U tests for numerical comparisons, and Chi-square tests for categorical variables. Dedicated manufacturer software was used for CPET data processing, and statistical analyses were conducted using R software (version 4.4.1).
Study design
- Observational model
- Case-control
- Time perspective
- Cross-sectional
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Type 1 diabetes group | – | –Male participants with confirmed T1DM diagnosis for ≥1 year who have completed a marathon. |
| Control Group | – | –Healthy male marathon runners matched by age, sex, and training background |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Adult marathon runners aged ≥18 years. Participants in the T1DM group with a confirmed diagnosis of T1DM for at least one year. The control group comprises healthy people with similar physical activity levels but no chronic health conditions.
Key inclusion criteria (3 listed)
- A diagnosis of T1DM for at least 1 year.
- Age ≥ 18 years.
- Written informed consent and adherence to the study protocol.
Key exclusion criteria (5 listed)
- Pregnancy.
- Use of medications significantly affecting metabolism or exercise performance
- Presence of chronic medical or psychiatric conditions limiting safe participation
- •Presence of advanced chronic complications of diabetes: proliferative retinopathy, diabetic kidney disease in stages III-V, cardiovascular diseases
- Inability to safely complete maximal exercise testing.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
VO₂max (mL/kg/min)
Time frame: single visit
peak oxygen uptake during graded exercise testing
6 secondary outcomes
Resting metabolic rate (kcal/day)
Time frame: single visit
Body adipose percentage [%]
Time frame: single visit
Lean tissue percentage [%]
Time frame: single visit
Forced Vital Capacity [L]
Time frame: single visit
Maximum Vital Capacity [L]
Time frame: single visit
Forced Expiratory Volume in 1 second [%]
Time frame: single visit
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 20 Apr 2025.
- Background: PubMed 28625918Shepherd JA, Ng BK, Sommer MJ, Heymsfield SB. Body composition by DXA. Bone. 2017 Nov;104:101-105. doi: 10.1016/j.bone.2017.06.010. Epub 2017 Jun 16.
- Background: PubMed 32709554Achamrah N, Delsoglio M, De Waele E, Berger MM, Pichard C. Indirect calorimetry: The 6 main issues. Clin Nutr. 2021 Jan;40(1):4-14. doi: 10.1016/j.clnu.2020.06.024. Epub 2020 Jul 2.
- Background: PubMed 17968581Poole DC, Wilkerson DP, Jones AM. Validity of criteria for establishing maximal O2 uptake during ramp exercise tests. Eur J Appl Physiol. 2008 Mar;102(4):403-10. doi: 10.1007/s00421-007-0596-3. Epub 2007 Oct 30.
- Background: PubMed 35032674Thuillier P, Domun N, Sonnet E, Le Ven F, Roudaut C, Kergus A, Kerlan V, Roudaut N. Prevention of exercise-induced hypoglycemia in 12 patients with type 1 diabetes running the Paris Marathon using continuous glucose monitoring: A prospective, single-center observational study. Diabetes Metab. 2022 Mar;48(2):101321. doi: 10.1016/j.diabet.2022.101321. Epub 2022 Jan 12.
- Background: PubMed 8299461Grimm JJ, Muchnick S. Type I diabetes and marathon running. Diabetes Care. 1993 Dec;16(12):1624. doi: 10.2337/diacare.16.12.1624a. No abstract available.
- Background: PubMed 32533229Riddell MC, Scott SN, Fournier PA, Colberg SR, Gallen IW, Moser O, Stettler C, Yardley JE, Zaharieva DP, Adolfsson P, Bracken RM. The competitive athlete with type 1 diabetes. Diabetologia. 2020 Aug;63(8):1475-1490. doi: 10.1007/s00125-020-05183-8. Epub 2020 Jun 12.
- Background: PubMed 22189486Chimen M, Kennedy A, Nirantharakumar K, Pang TT, Andrews R, Narendran P. What are the health benefits of physical activity in type 1 diabetes mellitus? A literature review. Diabetologia. 2012 Mar;55(3):542-51. doi: 10.1007/s00125-011-2403-2. Epub 2011 Dec 22.
- Derived from this study: PubMed 41184866Kulecki M, Daroszewski M, Birula P, Kreczmer A, Pietrzak M, Adamska A, Michalak M, Bonikowska A, Sroczynska A, Michalski M, Zozulinska-Ziolkiewicz D, Gawrecki A. Assessment of cardiorespiratory fitness and body composition in marathon runners with type 1 diabetes: an observational study. BMC Sports Sci Med Rehabil. 2025 Nov 3;17(1):317. doi: 10.1186/s13102-025-01303-2.
- Poznan University of Medical Sciences in Poznań is conducting the project "Development of the University Centre for Sports and Medical Studies in Poznań" (No. NdS/544750/2021/2022), funded by the Ministry of Education and Science under thLink provided by the sponsor.
- Individual participant dataSharing planned: No. IPD will not be shared due to the small sample size and the potential risk of participant re-identification, even with de-identified data. The study was not designed with broad data sharing in mind, and no participant consent was obtained for public data release.
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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.
Dorota Zozulinska-Ziolkiewicz, MD, PhD principal investigator
Department of Internal Medicine and Diabetology, Poznan University of Medical Sciences
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Type 1 Diabetes (T1D), run by Poznan University of Medical Sciences at 1 site in Poland.
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 5 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 20 Apr 2025. 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 Poland. 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. 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?
VO₂max (mL/kg/min) (time frame: single visit). 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 NCT06935903, 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 20 Apr 2025; AzTrials last refreshed its copy on 28 Oct 2026.