Map how the menstrual cycle affects blood sugar and energy while using closed-loop insulin

Menstrual Cycle Mapping While Using Closed-Loop Insulin Delivery

Observational Insel Gruppe AG, University Hospital Bern · NCT07478211

This study will test if normal menstrual hormone changes alter blood sugar control, insulin needs, and energy use in women aged 18–45 with type 1 diabetes.

Quick facts

Study typeObservational
Enrollment40 (estimated)
Ages18 Years to 45 Years
SexFemale
SponsorInsel Gruppe AG, University Hospital Bern Academic / other
Locations1 site (Bern, Canton of Bern)
Trial IDNCT07478211 on ClinicalTrials.gov

What this trial studies

This observational study follows natural-cycling women with type 1 diabetes across their menstrual cycles while they use their usual insulin therapy, including closed-loop systems when applicable. Researchers will characterize changes in glucose metabolism and energy balance that may be driven by hormone fluctuations, focusing on insulin sensitivity, gastric emptying, eating behavior, and energy expenditure. The study aims to map timing and magnitude of metabolic variation across follicular, ovulatory, and luteal phases to provide a detailed picture of cycle-related effects on glucose control. Data are intended to inform more precise timing of insulin adjustments and lifestyle advice.

Who should consider this trial

Good fit: Women aged 18–45 with type 1 diabetes, a natural menstrual cycle, and willingness to follow study procedures (including using mechanical contraception during participation) are ideal candidates.

Not a fit: People using hormonal contraceptives, other interventions that alter cyclical bleeding, or with conditions likely to interfere with glucose or energy metabolism are unlikely to benefit from this study.

Why it matters

Potential benefit: If successful, this could help personalize insulin dosing and meal planning across the menstrual cycle to improve glucose control and reduce hypoglycemia.

How similar studies have performed: Previous research suggests menstrual hormones can affect glucose and energy metabolism, but detailed natural-cycle metabolic data specifically in women with type 1 diabetes remain limited.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* 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

Exclusion Criteria:

* 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

Where this trial is running

Bern, Canton of Bern

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Diabetes Mellitus, Type 1Energy MetabolismWomens HealthMenstrual Cycle Physiology
Last reviewed 2026-06-09 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.