Insulin Action During Pregnancy in Woman at High Risk for Gestational Diabetes
Insulin Action During Pregnancy in Woman at High Risk for Gestational Diabetes
The project objective is to validate a new indirect estimate of insulin status in both
 pregnant African-American women and Caucasian women in southern Louisiana who are at risk for
 gestational diabetes mellitus. There are racial differences in carbohydrate metabolism that
 are potentially linked to complications during pregnancy and to increased risks of obesity
 and diabetes in later life. The investigators will explore the use of indexes of insulin
 status to identify the metabolic risk profile of pregnant women which may vary by race.
 Understanding whether there are differences which vary by race may influence clinical
 screening and treatment of pregnant women.
The major goal of our proposed study is to validate a new approach to estimating insulin
 sensitivity and ß-cell function in African-American women compared to non-Hispanic white
 women in southern Louisiana who are at a high risk for gestational diabetes mellitus (GDM).
 We will determine whether the whole body insulin sensitivity index (WBISI) and insulinogenic
 index (IGI) [derived from an oral glucose tolerance test (OGTT)] can be used during 24-28
 weeks of pregnancy to accurately estimate the degree of insulin resistance relative to ß-cell
 function in women with GDM in those with impaired glucose tolerance (IGT) as well as those
 who are glucose tolerant. Fasting values will also be assessed using the homeostasis model
 assessment (HOMA-IR and HOMA-%B) to evaluate insulin resistance and ß-cell function. We will
 explore the potential use of these measures to define the metabolic risk profile of these
 pregnant women and compare them with obstetric outcomes. We will determine if there are
 differences in risk that vary by race. Second, given the high likelihood that women who
 manifest GDM will develop type 2 diabetes mellitus (DM), identification of these patients by
 ethnic group or other independent determinants will permit intervention after delivery that
 might delay or prevent the onset of type 2 DM.
Inclusion Criteria:

 -  18-42 years of age

 -  at 20-30 weeks of gestation

 -  Caucasian or African-American and non-users of medications known to influence
 carbohydrate metabolism.

 Exclusion Criteria:

 -  <18 years or >42 years of age

 -  non-Caucasian or non-African-American ethnicity

 -  use of drugs that could interfere with glucose or insulin metabolism; or health
 problems such as diabetes mellitus or liver, heart, lung and kidney diseases