Diabetes Mellitus, Type 1MCM-LoopNCT07478211
Menstrual Cycle Mapping While Using Closed-Loop Insulin Delivery
An observational study of Diabetes Mellitus, Type 1 and Energy Metabolism, run by Lia Bally at 1 site in Switzerland.
Trial summary
The hypothesis is that menstrual cyclicity affects glucose and energy metabolism in women with type 1 diabetes. The rationale of the hypothesis on cycle effects builds on the assumption that fluctuations of female sex hormones across the menstrual cycle cause changes in physiological parameters of glucose metabolism… Read more about this study
- Who is it for?
- Ages 18 to 45 years, women only
- Conditions the study is for
- Diabetes Mellitus, Type 1, Energy Metabolism
- How many people
- 40 participants
- Where
- 1 siteSwitzerland
- Study dates
- 9 May 2025to 8 Sep 2026
- 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 to 45 years
- Women only
- No healthy volunteers
- Adult
Study population: Eligible participants will be women aged 18-45 years, with a natural menstrual cycle (occurring without medical or hormonal interventions), who have Type 1 Diabetes and are willing to follow study-related procedures.
Who may be able to join
- Female sex assigned at birth
- Type 1 diabetes for at least 12 months
- Aged 18-45 years
- Natural menstrual cycle (occurring without medical or hormonal interventions)
- Functional insulin therapy delivered via injection or insulin pump
- Willingness to follow study-related procedures
- Willingness to use mechanical contraception during the time of study participation
Who cannot join
- Use of contraceptives or medical interventions that interfere with natural hormonal fluctuations of the menstrual cycle or cyclical bleeding
- Interventions interfering with glucose or energy metabolism (other than insulin, thyroid hormone replacement or statins), as judged by the investigator, will be paused for the duration of the study, with an adequate washout duration prior to the start of data collection
- Presence of any physical or psychological condition, or any medical intervention likely to interfere with the conduct of the procedures and/or their evaluation, as judged by the investigator
- Pregnant or breast-feeding
- Participation in another clinical study that interferes with the interpretation of the study results as judged by the investigator
Trial locations and contacts
1 site in 1 country.
Switzerland1 site
Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism (UDEM), Inselspital, Bern University Hospital
Bern, Canton of Bern, 3010
About this study
The hypothesis is that menstrual cyclicity affects glucose and energy metabolism in women with type 1 diabetes. The rationale of the hypothesis on cycle effects builds on the assumption that fluctuations of female sex hormones across the menstrual cycle cause changes in physiological parameters of glucose metabolism and energy homeostasis and/or lifestyle aspects involved in the regulation of blood glucose and body weight. It is expected that hormone fluctuations affect insulin sensitivity, gastric emptying, eating behaviour and energy expenditure. It is anticipated that insulin sensitivity is highest in the pre-ovulatory phase and lowest in the mid-luteal phase. It is further expected that gastric emptying peaks in the follicular phase, and highest energy expenditure and dietary intake are expected during the mid-luteal phase.
The primary objective of this study is to characterize glucose and energy metabolism throughout the menstrual cycle in natural cycling women with type 1 diabetes. Further objectives are to assess the impact of the menstrual cycle on glucose control and insulin requirements, investigate how fluctuations in sex hormone levels influence glucose and energy metabolism, and quantify both inter- and intra-individual variability in metabolic changes related to the menstrual cycle. Additionally, the study will evaluate whether changes in key physiological components of glucose metabolism and behavioural factors mediate menstrual cycle-related variations in glucose control and insulin requirements.
- Conditions
- Diabetes Mellitus, Type 1, Energy Metabolism
- Keywords
- Womens Health, Menstrual Cycle Physiology
- Medical subject headings
- Diabetes Mellitus, Type 1
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 |
|---|---|---|
| Women with Type 1 Diabetes | Participants with type 1 diabetes from age 18 to 45 years and a natural menstrual cycle will be followed for 3 consecutive menstrual cycles. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Time in target glucose range
The primary metric for glucose control is the proportion of time with sensor glucose levels in the target range (3.9-10mmol/L, %).
Glucose levels will be measured using a continuous glucose monitoring sensor (Dexcom G6 or an equivalent CGM sensor).
Measured: Continuously over 3 menstrual cycles. Duration varies depending on individual cycle length, ranging from 60 days (20-day cycles) to 150 days (50-day cycles).
Secondary outcomes (7)
Algorithm-directed insulin delivery following a standardized meal
The primary insulin metric is the algorithm-directed insulin dose (units) delivered over a 3 hour period following a standardized meal without a manual bolus. Insulin delivery is recorded using the mylife CamAPS FX automated insulin delivery system.
Measured: The outcome will be measured at each standardized meal assessment, performed during the three key menstrual cycle phases (early-follicular, pre-ovulatory, and mid-luteal),across three menstrual cycles, resulting in a total of nine 3-hour assessment times
Insulin sensitivity
Insulin sensitivity will be estimated continuously throughout the study from sensor glucose and insulin pump data, collected via the mylife CamAPS FX automated insulin delivery system, using mathematical modeling.
Measured: Continuously over three menstrual cycles. Duration varies depending on individual cycle length, ranging from 60 days (20-day cycles) to 150 days (50-day cycles).
Gastric emptying
This outcome is based in the [13C]-acetate breath test. Breath 13CO2 enrichment is analyzed using infrared spectrometry and kinetics parameters are derived using mathematical modelling. The main parameter of interest is T50 (ie., the time until half of the ingested meal was absorbed).
This outcome is measured only in a subgroup of 15 participants.
Measured: The outcome is evaluated at each phase-specific assessment (early follicular, pre-ovulatory, and luteal) for one menstrual cycle.
Total energy expenditure
Total energy expenditure will be quantified using the doubly labelled water method. This outcome is measured only in a subgroup of 15 participants.
Measured: Continuously over one menstrual cycle. Duration varies depending on individual cycle length, ranging from 20 days to 50 days.
Substrate oxidation
Substrate oxidation (i.e, quantified by the relative contribution of fat oxidation to resting energy expenditure) will be measured by indirect calorimetry in the fasted state (≥8 hours) to provide additional context as a physiological determinant of glucose and energy metabolism. This outcome is measured only in a subgroup of 15 participants.
Measured: Assessed once at each phase-specific assessment (early follicular, pre-ovulatory, and luteal) for one menstrual cycle
Dietary intake
Total energy intake (kcal/day) will be assessed by recording all meals using an image-based automated food analysis application SNAQ.
Measured: Measured for 3 days following each phase-specific assessment (early follicular, pre-ovulatory, and luteal) across three menstrual cycles, totaling 27 days over 3 cycles
Physical activity
The number of steps per day, as a component of physical activity, will be measured using the Garmin Venu 3 smartwatch.
Measured: Continuously over 3 menstrual cycles. Duration varies depending on individual cycle length, ranging from 60 days (20-day cycles) to 150 days (50-day cycles).
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted17 Mar 2026
- Study start9 May 2025
- Primary completion8 Sep 2026
- Study completion8 Sep 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (7)Papers the sponsor has linked to this study.
- Other trials for Diabetes Mellitus, Type 1Studies 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 only
- Time perspective
- Prospective
- Enrolment
- 40 participants (actual)
Sponsor and investigators
- Lead sponsor
- Lia Bally
- Sponsor type
- University, hospital or other
- Collaborators
- Gertrud and Walter Siegenthaler Foundation, Bangerter Foundation and Swiss Academy of Medical Science, Innosuisse - Swiss Innovation Agency, CSEM Centre Suisse d'Electronique et de Microtechnique SA - Recherche et Developpement, University of Bern, Insel Gruppe AG, University Hospital Bern, DexCom, Inc., Fresenius Kabi (Schweiz) AG, Bern Medtech Collaboration Call, mylife Diabetescare AG, Burgergemeinde Bern
- Responsible party
- Sponsor-investigator, Lia Bally, Insel Gruppe AG, University Hospital Bern
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07478211
- Sponsor's protocol ID
- MCM-Loop
- Acronym
- MCM-Loop
- Status last verified
- Sep 2026
- First submitted
- 22 Dec 2025
- Last updated
- 16 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Individual participant data (IPD) will be made available upon reasonable request to the principal investigator.
Publications
Escalante Pulido JM, Alpizar Salazar M. Changes in insulin sensitivity, secretion and glucose effectiveness during menstrual cycle. Arch Med Res. 1999 Jan-Feb;30(1):19-22. doi: 10.1016/s0188-0128(98)00008-6.
PubMed 10071420Charkoudian N, Stachenfeld N. Sex hormone effects on autonomic mechanisms of thermoregulation in humans. Auton Neurosci. 2016 Apr;196:75-80. doi: 10.1016/j.autneu.2015.11.004. Epub 2015 Nov 30.
PubMed 26674572Hirshoren N, Tzoran I, Makrienko I, Edoute Y, Plawner MM, Itskovitz-Eldor J, Jacob G. Menstrual cycle effects on the neurohumoral and autonomic nervous systems regulating the cardiovascular system. J Clin Endocrinol Metab. 2002 Apr;87(4):1569-75. doi: 10.1210/jcem.87.4.8406.
PubMed 11932284Fede C, Albertin G, Petrelli L, Sfriso MM, Biz C, De Caro R, Stecco C. Hormone receptor expression in human fascial tissue. Eur J Histochem. 2016 Nov 2;60(4):2710. doi: 10.4081/ejh.2016.2710.
PubMed 28076930McEwen BS, Milner TA. Understanding the broad influence of sex hormones and sex differences in the brain. J Neurosci Res. 2017 Jan 2;95(1-2):24-39. doi: 10.1002/jnr.23809.
PubMed 27870427Mayes JS, Watson GH. Direct effects of sex steroid hormones on adipose tissues and obesity. Obes Rev. 2004 Nov;5(4):197-216. doi: 10.1111/j.1467-789X.2004.00152.x.
PubMed 15458395Sherman BM, Korenman SG. Hormonal characteristics of the human menstrual cycle throughout reproductive life. J Clin Invest. 1975 Apr;55(4):699-706. doi: 10.1172/JCI107979.
PubMed 1120778
Study at a glance
From the registry record, last updated by the sponsor on 16 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Menstrual Cycle Mapping While Using Closed-Loop Insulin Delivery
- ClinicalTrials.gov ID
- NCT07478211
- Acronym / sponsor ID
- MCM-Loop / MCM-Loop
- Conditions
- Diabetes Mellitus, Type 1, Energy Metabolism
- Keywords
- Womens Health, Menstrual Cycle Physiology
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 40 participants (actual)
- Lead sponsor
- Lia BallyUniversity, hospital or other
- Collaborators
- Gertrud and Walter Siegenthaler Foundation, Bangerter Foundation and Swiss Academy of Medical Science, Innosuisse - Swiss Innovation Agency, CSEM Centre Suisse d'Electronique et de Microtechnique SA - Recherche et Developpement, University of Bern, Insel Gruppe AG, University Hospital Bern, DexCom, Inc., Fresenius Kabi (Schweiz) AG, Bern Medtech Collaboration Call, mylife Diabetescare AG, Burgergemeinde Bern
- Study start
- 9 May 2025 (actual)
- Primary completion
- 8 Sep 2026 (actual)
- Study completion
- 8 Sep 2026 (actual)
- First posted
- 17 Mar 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 hypothesis is that menstrual cyclicity affects glucose and energy metabolism in women with type 1 diabetes. The rationale of the hypothesis on cycle effects builds on the assumption that fluctuations of female sex hormones across the menstrual cycle cause changes in physiological parameters of glucose metabolism and energy homeostasis and/or lifestyle aspects involved in the regulation of blood glucose and body weight. It is expected that hormone fluctuations affect insulin sensitivity, gastric emptying, eating behaviour and energy expenditure. It is anticipated that insulin sensitivity is highest in the pre-ovulatory phase and lowest in the mid-luteal phase. It is further expected that gastric emptying peaks in the follicular phase, and highest energy expenditure and dietary intake are expected during the mid-luteal phase.
The primary objective of this study is to characterize glucose and energy metabolism throughout the menstrual cycle in natural cycling women with type 1 diabetes. Further objectives are to assess the impact of the menstrual cycle on glucose control and insulin requirements, investigate how fluctuations in sex hormone levels influence glucose and energy metabolism, and quantify both inter- and intra-individual variability in metabolic changes related to the menstrual cycle. Additionally, the study will evaluate whether changes in key physiological components of glucose metabolism and behavioural factors mediate menstrual cycle-related variations in glucose control and insulin requirements.
Study design
- Observational model
- Case only
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Women with Type 1 Diabetes | – | –Participants with type 1 diabetes from age 18 to 45 years and a natural menstrual cycle will be followed for 3 consecutive menstrual cycles. |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult
- Study population
- Eligible participants will be women aged 18-45 years, with a natural menstrual cycle (occurring without medical or hormonal interventions), who have Type 1 Diabetes and are willing to follow study-related procedures.
Key inclusion criteria (7 listed)
- Female sex assigned at birth
- Type 1 diabetes for at least 12 months
- Aged 18-45 years
- Natural menstrual cycle (occurring without medical or hormonal interventions)
- Functional insulin therapy delivered via injection or insulin pump
Key exclusion criteria (5 listed)
- Use of contraceptives or medical interventions that interfere with natural hormonal fluctuations of the menstrual cycle or cyclical bleeding
- Interventions interfering with glucose or energy metabolism (other than insulin, thyroid hormone replacement or statins), as judged by the investigator, will be paused for the duration of the study, with an adequate washout duration prior to the start of data collection
- Presence of any physical or psychological condition, or any medical intervention likely to interfere with the conduct of the procedures and/or their evaluation, as judged by the investigator
- Pregnant or breast-feeding
- Participation in another clinical study that interferes with the interpretation of the study results as judged by the investigator
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
Time in target glucose range
Time frame: Continuously over 3 menstrual cycles. Duration varies depending on individual cycle length, ranging from 60 days (20-day cycles) to 150 days (50-day cycles).
The primary metric for glucose control is the proportion of time with sensor glucose levels in the target range (3.9-10mmol/L, %). Glucose levels will be measured using a continuous glucose monitoring sensor (Dexcom G6 or an equivalent CGM sensor).
7 secondary outcomes
Algorithm-directed insulin delivery following a standardized meal
Time frame: The outcome will be measured at each standardized meal assessment, performed during the three key menstrual cycle phases (early-follicular, pre-ovulatory, and mid-luteal),across three menstrual cycles, resulting in a total of nine 3-hour assessment times
Insulin sensitivity
Time frame: Continuously over three menstrual cycles. Duration varies depending on individual cycle length, ranging from 60 days (20-day cycles) to 150 days (50-day cycles).
Gastric emptying
Time frame: The outcome is evaluated at each phase-specific assessment (early follicular, pre-ovulatory, and luteal) for one menstrual cycle.
Total energy expenditure
Time frame: Continuously over one menstrual cycle. Duration varies depending on individual cycle length, ranging from 20 days to 50 days.
Substrate oxidation
Time frame: Assessed once at each phase-specific assessment (early follicular, pre-ovulatory, and luteal) for one menstrual cycle
Dietary intake
Time frame: Measured for 3 days following each phase-specific assessment (early follicular, pre-ovulatory, and luteal) across three menstrual cycles, totaling 27 days over 3 cycles
Physical activity
Time frame: Continuously over 3 menstrual cycles. Duration varies depending on individual cycle length, ranging from 60 days (20-day cycles) to 150 days (50-day cycles).
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 16 Sep 2026.
- Background: PubMed 10071420Escalante Pulido JM, Alpizar Salazar M. Changes in insulin sensitivity, secretion and glucose effectiveness during menstrual cycle. Arch Med Res. 1999 Jan-Feb;30(1):19-22. doi: 10.1016/s0188-0128(98)00008-6.
- Background: PubMed 26674572Charkoudian N, Stachenfeld N. Sex hormone effects on autonomic mechanisms of thermoregulation in humans. Auton Neurosci. 2016 Apr;196:75-80. doi: 10.1016/j.autneu.2015.11.004. Epub 2015 Nov 30.
- Background: PubMed 11932284Hirshoren N, Tzoran I, Makrienko I, Edoute Y, Plawner MM, Itskovitz-Eldor J, Jacob G. Menstrual cycle effects on the neurohumoral and autonomic nervous systems regulating the cardiovascular system. J Clin Endocrinol Metab. 2002 Apr;87(4):1569-75. doi: 10.1210/jcem.87.4.8406.
- Background: PubMed 28076930Fede C, Albertin G, Petrelli L, Sfriso MM, Biz C, De Caro R, Stecco C. Hormone receptor expression in human fascial tissue. Eur J Histochem. 2016 Nov 2;60(4):2710. doi: 10.4081/ejh.2016.2710.
- Background: PubMed 27870427McEwen BS, Milner TA. Understanding the broad influence of sex hormones and sex differences in the brain. J Neurosci Res. 2017 Jan 2;95(1-2):24-39. doi: 10.1002/jnr.23809.
- Background: PubMed 15458395Mayes JS, Watson GH. Direct effects of sex steroid hormones on adipose tissues and obesity. Obes Rev. 2004 Nov;5(4):197-216. doi: 10.1111/j.1467-789X.2004.00152.x.
- Background: PubMed 1120778Sherman BM, Korenman SG. Hormonal characteristics of the human menstrual cycle throughout reproductive life. J Clin Invest. 1975 Apr;55(4):699-706. doi: 10.1172/JCI107979.
- Individual participant dataSharing planned: Yes. Individual participant data (IPD) will be made available upon reasonable request to the principal investigator.
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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.
The record lists no contact. Use the official record to reach the sponsor.
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 Diabetes Mellitus, Type 1 and Energy Metabolism, run by Lia Bally at 1 site in Switzerland.
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 7 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 16 Sep 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 Switzerland. 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?
Time in target glucose range (time frame: Continuously over 3 menstrual cycles. Duration varies depending on individual cycle length, ranging from 60 days (20-day cycles) to 150 days (50-day cycles).). 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 NCT07478211, which also lists 7 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 16 Sep 2026.