Menstrual Cycle Mapping While Using Closed-Loop Insulin Delivery

NCT07478211 | Active Not Recruiting

• 1 other identifier: MCM-Loop
• Study Type: observational
• Target: 40
• Locations: 1 country
• Sites: 1

Brief 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 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

Outcome Measures

Primary Outcomes (1)

• 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).

  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 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

  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

  The outcome is evaluated at each phase-specific assessment (early follicular, pre-ovulatory, and luteal) for one menstrual cycle.

• Total energy expenditure

  Continuously over one menstrual cycle. Duration varies depending on individual cycle length, ranging from 20 days to 50 days.

• Substrate oxidation

  Assessed once at each phase-specific assessment (early follicular, pre-ovulatory, and luteal) for one menstrual cycle

Other Outcomes (26)

• Postprandial mean glucose

  The outcome will be evaluated continuously over 3 menstrual cycles (duration varies from 60 days (20-day cycles) to 150 days (50-day cycles)) as well as at each standardized meal assessment, resulting in a total of nine 3-hour assessment times.

• Postprandial peak glucose

  The outcome will be evaluated continuously over 3 menstrual cycles (duration varies from 60 days (20-day cycles) to 150 days (50-day cycles)) as well as once for each standardized meal assessment (9 values in total).

• Proportion of time spent in the hyperglycaemic range

  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)

Study Arms (1)

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.

Eligibility Criteria

• Age: 18 Years - 45 Years
• Sex: female
• Healthy Volunteers: No
• Age Groups: Adult (18-64)
• Sampling Method: Probability Sample

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.

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• Lia Bally: lead
• Burgergemeinde: collaborator
• mylife Diabetes Care AG: collaborator
• Innosuisse - Swiss Innovation Agency: collaborator
• DexCom, Inc.: collaborator
• University of Bern: collaborator
• Fresenius Kabi (Schweiz) AG: collaborator
• Bern Medtech Collaboration Call: collaborator
• Gertrud and Walter Siegenthaler Foundation: collaborator
• Insel Gruppe AG, University Hospital Bern: collaborator
• Bangerter Foundation and Swiss Academy of Medical Science: collaborator
• CSEM Centre Suisse d'Electronique et de Microtechnique SA - Recherche et Developpement: collaborator

Study Sites (1)

Department of Diabetes, Endocrinology, Nutritional Medicine and Metabolism (UDEM), Inselspital, Bern University Hospital

Bern, Canton of Bern, 3010, Switzerland

Location

Related Publications (7)

• 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.

  PMID: 10071420 BACKGROUND

• Charkoudian 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.

  PMID: 26674572 BACKGROUND

• Hirshoren 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.

  PMID: 11932284 BACKGROUND

• Fede 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.

  PMID: 28076930 BACKGROUND

• McEwen 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.

  PMID: 27870427 BACKGROUND

• Mayes 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.

  PMID: 15458395 BACKGROUND

• Sherman 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.

  PMID: 1120778 BACKGROUND

Biospecimen

Retention: SAMPLES WITHOUT DNA

Urine, Serum, Breath Samples

MeSH Terms

Conditions

Diabetes Mellitus, Type 1

Condition Hierarchy (Ancestors)

Diabetes Mellitus; Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Endocrine System Diseases; Autoimmune Diseases; Immune System Diseases

Study Design

• Study Type: observational
• Observational Model: CASE ONLY
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Prof. Dr. med. et phil.

Study Record Dates

• First Submitted: December 22, 2025
• First Posted: March 17, 2026
• Study Start: May 9, 2025
• Primary Completion (Estimated): September 30, 2026
• Study Completion (Estimated): September 30, 2026
• Last Updated: June 2, 2026

Record last verified: 2026-05

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, ANALYTIC CODE
• Time Frame: IPD will be made availabe starting 12 month after publication of trial results.
• Access Criteria: Ethics approval, as applicable under Swiss legislation, will need to be obtained by those requesting the data. Additionally, a data transfer and processing agreement must be in place to ensure compliance with data protection regulations.

Locations

CH (1)