Glycemic Variations During the Menstrual Cycle in Women With Type 1 Diabetes (GLYMETY)

Glycemic Variations During the Menstrual Cycle in Women With Type 1 Diabetes: the GLYMETY Study

In clinical practice, women living with type 1 diabetes frequently report that insulin requirements change across the menstrual cycle. Consequently, glycemic fluctuations are observed. This phenomenon could be explained by a decrease in insulin sensitivity during the second half of the menstrual cycle (luteal phase).

Overall, despite an important proportion of women reporting glycemic and/or insulin variations across the menstrual cycle, studies to date have involved small sample sizes, and have had inconsistent results. The objective of this study will be to study glycemic fluctuations across the menstrual cycle using CGM data, alongside insulin data, in a large sample of women.

Study Overview

• Status: Recruiting
• Conditions: Type1diabetes
• Intervention / Treatment: Device: Continuous glucose monitoring; Drug: Insulin; Other: Premenstrual symptoms; Other: Ovulation kits; Device: Fitbit Inspire 2; Other: Keenoa; Other: Menstrual cycle

• Study Type: Observational
• Enrollment (Estimated): 86

Contacts and Locations

• Study Contact: Name: Anne Bonhoure; Phone Number: 3238 514-987-5500; Email: anne.bonhoure@ircm.qc.ca

Study Locations

• Canada
  • Quebec
    • Montreal, Quebec, Canada, H2W 1R7
      • Recruiting
      • Institut de recherches cliniques de Montreal
      • Principal Investigator: Rémi Rabasa-Lhoret
      • Contact: Anne Bonhoure; Phone Number: 3238 514-987-5500; Email: anne.bonhoure@ircm.qc.ca

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 50 years (Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Women aged 18 to 50 living with type 1 diabetes.

Description

Inclusion Criteria:

1. Females aged 18 to 50 living in Canada.
2. Clinical diagnosis of type 1 diabetes or latent autoimmune diabetes in adults (LADA) for at least one year.
3. Using insulin pump therapy, multiple daily injections or automated insulin delivery systems for at least 3 months.
4. Using a continuous glucose monitoring (CGM) system.
5. Having at least one menses in the last 40 days.
6. Accepting to share CGM data with the research team and if applicable insulin pump data.This access will be limited to the study period.
7. Having a smartphone or tablet to follow menstrual cycles.
8. Stable weight (less than 5% variation in the last 3 months).

Exclusion Criteria:

1. Using a hormonal contraception method that eliminates menses (Depo Provera, progestin intrauterine device, extented-cycle regimen with birth control pill)
2. Using regular insulin (Entuzity U500, Novolin ge Toronto or Humulin R).
3. Clinically significant nephropathy (eGFR < 30 ml/min/1.73m2, planned or on dialysis) or neuropathy (e.g., known uncontrolled gastroparesis) as judged by the investigator.
4. Recent (< 6 months) acute macrovascular event (e.g., acute coronary syndrome or cardiac surgery).
5. Anticipated therapeutic change (including change of insulin type and/or type of CGM sensor, insulin pump or AID (automated insulin device) system) between admission and end of the study.
6. Anticipated change in contraception method or plan to begin or stop a contraceptive method.
7. Anticipated need to use acetaminophen during the study period at a dose above 1g every 6 hours.
8. Pregnancy (ongoing or current attempt to become pregnant)
9. Breastfeeding
10. Uncontrolled thyroid disease (TSH should be in target range and treatment stable for at least 6 weeks).
11. Severe hypoglycemic episode within two weeks of screening
12. Severe hyperglycemic episodes requiring hospitalization in the last 3 months.
13. Current use of glucocorticoid medication (except low stable dose and inhaled steroids and stable adrenal insufficiency treatment e.g., Cortef®)
14. Agents affecting gastric emptying (Motilium®, Victoza®, Ozempic®, Trulicity®, Byetta® and Symlin®) as well as oral anti-diabetic agents (Metformin, Prandase®, DPP-4 inhibitors) unless at a stable dose for 3 months and without anticipated change during the study.
15. Current use of SGLT-2 inhibitors unless at a stable dose for at least 3 months, without anticipated change during the study and appropriate ketone testing is performed.
16. Other serious medical illnesses which likely interfere with study participation or with the ability to complete the study by the judgment of the investigator.
17. Anticipation of a significant change in exercise or diet regimen between admission and end of the study (i.e., starting or stopping an organized sport; planned significant diet change).
18. Anticipated radiologic examination incompatible with CGM wear for more than 10 days between admission and end of the study (e.g., repeated MRI).
19. In the opinion of the investigator, a participant who is unable or unwilling to complete the study.
20. If taking medication for hypothyroidism, no change of dose (Levothyroxin) in the last 6 weeks.

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Other

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Women with type 1 diabetes

Device: Continuous glucose monitoring; Glucose levels will be measured using continuous glucose monitoring; Drug: Insulin; Insulin doses will be retrieved from insulin pump reports (for insulin pump users) or journals for (for multiple daily injections users); Other: Premenstrual symptoms; Premenstrual symptoms will be assessed using the Premenstrual symptoms screening tool; Other: Ovulation kits; Ovulation testing will be done using ovulation kits; Device: Fitbit Inspire 2; Physical activity will be assessed using the Fitbit Inspire 2; Other: Keenoa; Food intake will be assessed using the Keenoa phone application; Other: Menstrual cycle; The application My Calendar will be used to record information on the menstrual cycle

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Mean glucose levels during the early follicular phase	Day 1 to 5 of the menstrual cycle
Mean glucose levels during the mid-late follicular phase	Day 6 until 2 days prior to ovulation
Mean glucose levels during the periovulation phase	Ovulation plus/minus 1 day
Mean glucose levels during the early luteal phase	Day 2 to 4 after ovulation
Mean glucose levels during the mid-luteal phase	Day 5 to 9 after ovulation
Mean glucose levels during the late luteal phase	Day 10 after ovulation until the first day of the next menstrual cycle

Secondary Outcome Measures

Outcome Measure	Time Frame
Percentage of time of glucose levels between 3.9 and 7.8 mmol/L	Day 1 to 5 of the menstrual cycle
Percentage of time of glucose levels between 3.9 and 7.8 mmol/L	Day 6 until 2 days prior to ovulation
Percentage of time of glucose levels between 3.9 and 7.8 mmol/L	Ovulation plus/minus 1 day
Percentage of time of glucose levels between 3.9 and 7.8 mmol/L	Day 2 to 4 after ovulation
Percentage of time of glucose levels between 3.9 and 7.8 mmol/L	Day 5 to 9 after ovulation
Percentage of time of glucose levels between 3.9 and 7.8 mmol/L	Day 10 after ovulation until the first day of the next menstrual cycle
Percentage of time of glucose levels between 3.9 and 10.0 mmol/L	Day 1 to 5 of the menstrual cycle
Percentage of time of glucose levels between 3.9 and 10.0 mmol/L	Day 6 until 2 days prior to ovulation
Percentage of time of glucose levels between 3.9 and 10.0 mmol/L	Ovulation plus/minus 1 day
Percentage of time of glucose levels between 3.9 and 10.0 mmol/L	Day 2 to 4 after ovulation
Percentage of time of glucose levels between 3.9 and 10.0 mmol/L	Day 5 to 9 after ovulation
Percentage of time of glucose levels between 3.9 and 10.0 mmol/L	Day 10 after ovulation until the first day of the next menstrual cycle
Percentage of time of glucose levels below 3.9 mmol/L	Day 1 to 5 of the menstrual cycle
Percentage of time of glucose levels below 3.9 mmol/L	Day 6 until 2 days prior to ovulation
Percentage of time of glucose levels below 3.9 mmol/L	Ovulation plus/minus 1 day
Percentage of time of glucose levels below 3.9 mmol/L	Day 2 to 4 after ovulation
Percentage of time of glucose levels below 3.9 mmol/L	Day 5 to 9 after ovulation
Percentage of time of glucose levels below 3.9 mmol/L	Day 10 after ovulation until the first day of the next menstrual cycle
Percentage of time of glucose levels below 3.0 mmol/L	Day 1 to 5 of the menstrual cycle
Percentage of time of glucose levels below 3.0 mmol/L	Day 6 until 2 days prior to ovulation
Percentage of time of glucose levels below 3.0 mmol/L	Ovulation plus/minus 1 day
Percentage of time of glucose levels below 3.0 mmol/L	Day 2 to 4 after ovulation
Percentage of time of glucose levels below 3.0 mmol/L	Day 5 to 9 after ovulation
Percentage of time of glucose levels below 3.0 mmol/L	Day 10 after ovulation until the first day of the next menstrual cycle
Percentage of time of glucose levels above 10.0 mmol/L	Day 1 to 5 of the menstrual cycle
Percentage of time of glucose levels above 10.0 mmol/L	Day 6 until 2 days prior to ovulation
Percentage of time of glucose levels above 10.0 mmol/L	Ovulation plus/minus 1 day
Percentage of time of glucose levels above 10.0 mmol/L	Day 2 to 4 after ovulation
Percentage of time of glucose levels above 10.0 mmol/L	Day 5 to 9 after ovulation
Percentage of time of glucose levels above 10.0 mmol/L	Day 10 after ovulation until the first day of the next menstrual cycle
Percentage of time of glucose levels above 13.9 mmol/L	Day 1 to 5 of the menstrual cycle
Percentage of time of glucose levels above 13.9 mmol/L	Day 6 until 2 days prior to ovulation
Percentage of time of glucose levels above 13.9 mmol/L	Ovulation plus/minus 1 day
Percentage of time of glucose levels above 13.9 mmol/L	Day 2 to 4 after ovulation
Percentage of time of glucose levels above 13.9 mmol/L	Day 5 to 9 after ovulation
Percentage of time of glucose levels above 13.9 mmol/L	Day 10 after ovulation until the first day of the next menstrual cycle
Standard deviation of glucose levels	Day 1 to 5 of the menstrual cycle
Standard deviation of glucose levels	Day 6 until 2 days prior to ovulation
Standard deviation of glucose levels	Ovulation plus/minus 1 day
Standard deviation of glucose levels	Day 2 to 4 after ovulation
Standard deviation of glucose levels	Day 5 to 9 after ovulation
Standard deviation of glucose levels	Day 10 after ovulation until the first day of the next menstrual cycle
Coefficient of variance of glucose levels	Day 1 to 5 of the menstrual cycle
Coefficient of variance of glucose levels	Day 6 until 2 days prior to ovulation
Coefficient of variance of glucose levels	Ovulation plus/minus 1 day
Coefficient of variance of glucose levels	Day 2 to 4 after ovulation
Coefficient of variance of glucose levels	Day 5 to 9 after ovulation
Coefficient of variance of glucose levels	Day 10 after ovulation until the first day of the next menstrual cycle
Low blood glucose index	Day 1 to 5 of the menstrual cycle
Low blood glucose index	Day 6 until 2 days prior to ovulation
Low blood glucose index	Ovulation plus/minus 1 day
Low blood glucose index	Day 2 to 4 after ovulation
Low blood glucose index	Day 5 to 9 after ovulation
Low blood glucose index	Day 10 after ovulation until the first day of the next menstrual cycle
High blood glucose index	Day 1 to 5 of the menstrual cycle
High blood glucose index	Day 6 until 2 days prior to ovulation
High blood glucose index	Ovulation plus/minus 1 day
High blood glucose index	Day 2 to 4 after ovulation
High blood glucose index	Day 5 to 9 after ovulation
High blood glucose index	Day 10 after ovulation until the first day of the next menstrual cycle
Standard deviation of insulin delivery	Day 1 to 5 of the menstrual cycle
Standard deviation of insulin delivery	Day 6 until 2 days prior to ovulation
Standard deviation of insulin delivery	Ovulation plus/minus 1 day
Standard deviation of insulin delivery	Day 2 to 4 after ovulation
Standard deviation of insulin delivery	Day 5 to 9 after ovulation
Standard deviation of insulin delivery	Day 10 after ovulation until the first day of the next menstrual cycle
Coefficient of variance of insulin delivery	Day 1 to 5 of the menstrual cycle
Coefficient of variance of insulin delivery	Day 6 until 2 days prior to ovulation
Coefficient of variance of insulin delivery	Ovulation plus/minus 1 day
Coefficient of variance of insulin delivery	Day 2 to 4 after ovulation
Coefficient of variance of insulin delivery	Day 5 to 9 after ovulation
Coefficient of variance of insulin delivery	Day 10 after ovulation until the first day of the next menstrual cycle
Total insulin delivery	Day 1 to 5 of the menstrual cycle
Total insulin delivery	Day 6 until 2 days prior to ovulation
Total insulin delivery	Ovulation plus/minus 1 day
Total insulin delivery	Day 2 to 4 after ovulation
Total insulin delivery	Day 5 to 9 after ovulation
Total insulin delivery	Day 10 after ovulation until the first day of the next menstrual cycle

Collaborators and Investigators

• Sponsor: Institut de Recherches Cliniques de Montreal
• Investigators: Principal Investigator: Rémi Rabasa-Lhoret, Institut de recherches cliniques de Montreal

Study record dates

Study Major Dates

• Study Start (Actual): May 2, 2022
• Primary Completion (Estimated): April 1, 2026
• Study Completion (Estimated): May 31, 2026

Study Registration Dates

• First Submitted: February 17, 2022
• First Submitted That Met QC Criteria: February 17, 2022
• First Posted (Actual): February 28, 2022

Study Record Updates

• Last Update Posted (Actual): March 5, 2026
• Last Update Submitted That Met QC Criteria: March 3, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: Physical activity; Continuous glucose monitoring; Menstrual cycle; Food intake; Insulin dose
• Additional Relevant MeSH Terms: Behavior; Motor Activity; Hormones; Hormones, Hormone Substitutes, and Hormone Antagonists; Peptide Hormones; Peptides; Amino Acids, Peptides, and Proteins; Investigative Techniques; Clinical Laboratory Techniques; Diagnostic Techniques and Procedures; Diagnosis; Insulins; Pancreatic Hormones; Proinsulin; Reproductive Physiological Phenomena; Reproductive and Urinary Physiological Phenomena; Blood Chemical Analysis; Clinical Chemistry Tests; Diagnostic Techniques, Endocrine; Monitoring, Physiologic; Insulin; Continuous Glucose Monitoring; Menstrual Cycle
• Other Study ID Numbers: 2022-1165

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No