Comprehensive Postpartum Screening Strategies for Women With Gestational Diabetes Mellitus (GDM)
Comprehensive Postpartum Screening Strategies for Women With Gestational Diabetes Mellitus (GDM)
Previous gestational diabetes (GDM) predisposes affected women to diabetes. Pregnancy, in
 essence, serves as a metabolic stress test and uncovers underlying insulin resistance and
 ß-cell dysfunction. Cumulative incidence rates of type 2 diabetes (DM2) among women with a
 history of GDM vary widely depending on the length of follow up and the underlying risk of
 diabetes in the population. Like DM2, the incidence of postpartum diabetes appears to be
 increasing The cumulative incidence of DM2 varied from 2.6 to > 70% in studies with
 postpartum follow-up ranging from 6 weeks to 28 years. Among women with a history of
 gestational diabetes, it is generally accepted that race, age, parity, family history of
 diabetes, pre-pregnancy weight, postpartum obesity, and weight gain are risk factors for
 developing DM2. Other suspected risk factors include smoking, physical inactivity, diet, and
 drugs that adversely affect glucose metabolism. Despite the high and increasing rate of DM2
 in Louisiana, the medical community does not have reliable estimates of the number of woman
 living in southern Louisiana who develop diabetes subsequent to GDM. At Woman's Hospital, the
 investigators had 8246 deliveries in 2007; 7873 mothers (95% of deliveries) were either
 African American or Caucasian. Of this group of women, 665 were diagnosed with gestational
 diabetes mellitus. Thus, around 8.5% of the African American and Caucasian women delivering
 babies at Woman's Hospital in 2007 had a glucose abnormality. The incidence of diabetes and
 impaired glucose metabolism in the immediate postpartum period and within 12 months after
 delivery in this population is unknown. There are no long-term studies performed in Louisiana
 that have compared the benefits of different screening strategies or evaluated an optimum
 testing frequency after GDM to reduce the rate of DM2 and cardiovascular disease (CVD) in
 these high-risk women. The investigators plan to use this study as an outreach effort to
 provide screening for previous gestational diabetic mothers without adequate medical coverage
 following delivery.
Women with previous gestational diabetes constitute an ideal group for the development,
 testing, and implementation of clinical strategies for primary diabetes prevention. One-third
 to one-half of women with a history of GDM will develop type 2 (DM2) within 3-5 years and 70%
 will develop DM2 if followed >10 years. Studies have shown that measuring only the fasting
 glucose level postpartum is not sufficiently sensitive to identify all women who have
 impaired glucose tolerance (IGT) or DM2. Data presented at the Fifth International
 Workshop-Conference on GDM indicated that, postpartum, only 34% of the women with IGT or DM2
 had impaired fasting glucose and that 44% of those with DM2 had fasting levels below 100
 mg/dl (<5.5 mmol/l). The recommended process to detect permanent diabetes in women who have
 had GDM and who might become pregnant again is a 75-g 2-h oral glucose tolerance test (OGTT)
 6-12 weeks post partum and every year thereafter. Postpartum management of women with GDM is
 critical because of their markedly increased risk of DM2 and its comorbidities in the future
 Follow-up studies of women with GDM are necessary to establish the most efficient and
 most-effective approach to postpartum screening for type 2 diabetes. This study will examine
 the diagnostic effectiveness of OGTT-derived glucose tolerance, insulin secretion and insulin
 sensitivity indices compared with indices derived from fasting values of glucose and insulin
 in subjects with GDM performed post-partum. We will establish whether post-partum fasting
 and/or glucose-stimulated indices of insulin sensitivity and secretion most accurately
 estimate the degree of insulin resistance relative to ß-cell function in all race/ethnicity
 groups of women after delivery of a pregnancy complicated by gestational diabetes and predict
 their risk for development of diabetes and CVD. .Primary Objective1) We will identify,
 recruit and test 100 individuals with prior GDM in order to:§ Determine the best way to
 assess glucose tolerance disorders' prevalence after pregnancy complicated by GDM in southern
 Louisiana.§ Determine the most effective screening strategy to identify those women with
 prior GDM who develop or are at high risk for developing DM2 and comorbidities postpartum.A 2
 hr, 75-gram OGTT with measurements of insulin and glucose will be performed at their 6-12
 week and 1-year post-delivery check-up; this will be compared with the results of their
 single fasting glucose and insulin value.Secondary Objectives1) We will measure
 cardiometabolic markers (lipids, blood pressure) in the COPS-GDM study in order to:§ Identify
 the frequency and value of CVD risk markers in women with glucose abnormalities persisting
 after pregnancies with GDMGlucometabolic perturbations carry a particularly high risk for
 metabolic syndrome in women with prior GDM. Woman with prior GDM shown to have higher blood
 pressure and an altered lipid profile with increased LDL cholesterol and triglyceride levels
 and decreased HDL cholesterol levels that correlate with cardiovascular disease (CVD) risk
 factors2) We will measure anthropometric measures (body weight, BMI, abdominal girth) and
 liver aminotransferase levels (ALT, AST) in order to:§ Determine if there is a higher
 prevalence of postpartum glucose abnormalities in women with prior GDM predicted by BMI
 category and/or abdominal adiposity § Determine if elevated abnormal aminotransferase
 activity is more prominent in prior GDM women and the relationship to subsequent diabetes
 Former gestational diabetic mothers when compared with women with no history of GDM are found
 to have higher body mass index (BMI) and visceral adiposity. The distribution of postpartum
 glucose abnormalities by BMI category was found to be more common with increased BMI.3) We
 will investigate the impact of breastfeeding in women with a prior GDM on glucose tolerance
 and CVD risk factors to:§ Determine if lactation has immediate and long-term favorable
 effects in this patient population postpartum.Breast-feeding has been associated with
 significantly lower triglyceride level, higher HDL cholesterol, lower total cholesterol/HDL
 ratio, lower mean fasting glucose, and lower prevalence of any postpartum abnormality of
 glucose tolerance, including diabetes. Breastfeeding has also been reported to lower the rate
 of overt diabetes developing later in life in women with a history of gestational diabetes.
Inclusion Criteria:

 -  Postpartum Women (6-12 weeks)who experienced GDM during index pregnancy 18 years to 42
 years of age

 -  English-speaking

 -  Written consent for participation in the study

 Exclusion Criteria (Medical):

 -  Cholestasis during the past pregnancy

 -  Serum AST and/or ALT level exceeding more than twice normal laboratory values

 -  History or clinical manifestation of cardiovascular disease

 -  History or clinical manifestation of diabetes or use of anti-diabetic drugs before
 pregnancy

 -  History or clinical manifestation of any other significant metabolic, hematologic,
 pulmonary, cardiovascular, gastrointestinal, neurologic, immune, hepatic, renal,
 urologic disorders, or cancer

 -  Regular use of medications for weight control, psychosis and hormonal birth control

 -  Current use of medication to treat diabetes

 Exclusion Criteria (Psychiatric and Behavioral):

 -  History or clinical manifestation of any eating disorder

 -  Individuals who smoke

 -  History of drug or alcohol abuse (up to 14 drinks a week are allowed) within the past
 two years

 Other Exclusion Criteria:

 -  Pregnancy or pregnancy planned during the coming year

 -  Not willing or unable to adhere to the clinical evaluation schedule over the twelve
 -month study period