Blood Glucose Variability and Insulin Action During Menstrual Cycle in Females With Type 1 Diabetes

Type 1 Diabetes (T1D) is a chronic disease that leads to disability and premature death if
not well treated. While females and males are equally affected by T1D, diabetes places
additional burdens of care on females. Characteristically, females with T1D have worse
glycemic control, a higher incidence of diabetic ketoacidosis, and a greater risk of
cardiovascular complications as compared to their male peers. It has been hypothesized that
variations in responsiveness to pre-meal bolus doses of insulin during menstrual cycling is
an important underlying cause for increased management problems in females with T1D, but the
hypothesis has not been adequately tested. Consequently, insulin treatment of females during
the different cycles of menstruation remains a guessing game that often results in major
swings in blood glucose from high to low levels. The unfavorable impact of this gap in
knowledge extends to the efficiency and accuracy of artificial pancreas closed-loop (CL)
system insulin delivery algorithms designed based on insulin action parameters. The proposed
study addresses this unmet need in diabetes management for females both in open-loop (OL) and
CL therapies.

Inclusion Criteria:

1. Age 12-35

2. diagnosis of T1D>1year;

3. BMI%<85th;

4. HbA1c <9%.

5. Subjects ages 21-35y on combination oral contraceptive pills (OCP) could be included.

Exclusion Criteria:

1. irregular periods,

2. pregnant, breastfeeding,

3. subjects>20y on progesterone only pills or injections,

4. Likelihood of requiring treatment during the study period with drugs not permitted by
the study protocol,

5. mental condition rendering the subject unable to understand the nature, scope and
possible consequences of the study, including blood glucose monitoring requirements
including the documentation of blood glucose data and insulin dosing,and/or inability
to return for follow-up visits, and unlikely to complete the study.

6. Subjects on OCP will be excluded in the 12-20y group to capture the physiologic
variability in insulin action during pubertal progress.