Gestational Diabetes Mellitus
Conditions
Keywords
Insulin sensitivity, Insulin secretion, Pregnancy, Placental proteins
Brief summary
It is unknown whether beta cell dysfunction and insulin resistance in Gestational Diabetes Mellitus (GDM) is representative of a chronic maternal defect, unmasked by pregnancy, or whether it is the result of an imbalance of a placental hormones. Undiscovered placental factors which vary between pregnancies likely contribute to the pathogenesis of GDM. To elucidate the pathophysiology underlying GDM, the investigators will attempt to discover these factors and characterize pregnancy-associated changes in insulin secretion and sensitivity in women with and without GDM.
Detailed description
Gestational diabetes mellitus (GDM) complicates 3-7% of pregnancies in the United States and is associated with perinatal morbidity and a high risk of future maternal type 2 diabetes. Current prevention and treatment of GDM relies on techniques developed in the type 2 diabetes population, without regard to unique physiology in pregnancy. GDM occurs in the setting of profound pregnancy changes in glucose metabolism: late pregnancy is normally characterized by marked insulin resistance. In order to maintain normal glucose levels and avoid GDM, pancreatic beta cells must augment insulin secretion to compensate. Women with GDM have inadequate beta-cell compensation for pregnancy-induced insulin resistance, resulting in hyperglycemia. It is unknown whether beta cell dysfunction and insulin resistance in GDM is representative of a chronic maternal defect, unmasked by pregnancy, or whether it is the result of an imbalance of a placental hormones. Undiscovered placental factors which vary between pregnancies likely contribute to the pathogenesis of GDM. Discovery of these factors and elucidation of the pathophysiology underlying GDM will allow for the development better GDM-specific prevention and treatment strategies.
Interventions
OTHEROral glucose tolerance test
75 gram oral glucose tolerance test (fasting) at: Visit 1 (pregnant \[4-14 weeks gestation\] and nonpregnant women); Visit 2 (pregnant subjects only at 24-28 weeks gestation); Visit 3 (pregnant subjects only at 6-12 weeks postpartum)
Sponsors
Massachusetts General Hospital
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 44 Years
Healthy volunteers
No
Inclusion criteria
* Women, age 18-44, non-pregnant OR in the 1st trimester of pregnancy (4-14 weeks gestation), * Who had GDM in a previous pregnancy * At risk for diabetes mellitus, as specified by the American Diabetes Association (ADA): * BMI ≥ 25 kg/m2 (or BMI ≥ 23 kg/m2 if Asian-American) PLUS one or more of the following: * history of giving birth to a neonate weighing \> 9 lbs * first-degree family member with diabetes mellitus * high-risk ethnic or racial group (African-American, Hispanic, Native American, Asian-American, or Pacific Islander) * polycystic ovary syndrome * hypertension, dyslipidemia if known (HDL\<45 and/or triglyceride level \>250), or cardiovascular disease * physical inactivity
Exclusion criteria
* Known pre-existing diabetes mellitus, based on patient report or medical record review * A1C ≥ 6.5%, detected at study visit 1 * Use of medications known to affect glucose tolerance including corticosteroids, metformin, sulfonylureas, and others as determined by the investigators.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Insulin secretory response | 1st trimester (gestational weeks 4-14) | Insulin secretory response to a glucose load (insulinogenic index), adjusted for differences in insulin resistance, in pregnant women in the 1st trimester will be compared to the insulin secretory response in non-pregnant women |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Insulin secretory response | Mid-pregnancy (gestational weeks 24-28) | Insulin secretory response to a glucose load (insulinogenic index), adjusted for differences in insulin resistance, in pregnant women at 24-28 weeks gestation will be compared to the insulin secretory response in non-pregnant women |
| Change in insulin secretory response | 1st trimester to 24-28 weeks gestation | Change in insulin secretory response to a glucose load (insulinogenic index) between 1st trimester and 24 to 28 weeks gestation, adjusted for changes in insulin resistance, in pregnant women who do and do not develop GDM |
Countries
United States
Outcome results
None listed