Genetics of Beta Cell Failure in Mexican Americans

This is a family based genotype-phenotype study designed to assess genetic and environmental influences on obesity, insulin resistance and beta cell function in the context of gestational diabetes.

Study Overview

• Status: Completed
• Conditions: Obesity; Physical Activity; Insulin Resistance; Genetics; Air Pollution; Gestational Diabetes; Nutrition; Diabetes Type 2; Adipokines; Beta Cell Function

Detailed Description

Mexican American women with prior gestational diabetes and their first degree relatives and Mexican American women with prior normal glucose tolerance in pregnancy are studied with detailed phenotyping consisting of oral and intravenous glucose tolerance tests, body composition studies, diet and physical activity assessments, and circulating biomarkers potentially related to obesity, insulin resistance, pancreatic beta cell function, gestational diabetes and type 2 diabetes. Spouses of the gestational diabetic and control probands are studied with oral glucose tolerance tests. Offspring of the gestational and control probands have fasting glucose determinations. All participants provide DNA for genetics testing. A subset of the gestational diabetic probands and their first degree relatives return 3-5 years after baseline testing for repeat phenotyping.

• Study Type: Observational
• Enrollment (Actual): 1250

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 8 years and older (Child, Adult, Older Adult)
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

See Inclusion and Exclusion Criteria

Description

INCLUSION CRITERIA

1. Probands with Prior Gestational Diabetes Mellitus ("GDM PROBANDS")

   • Mexican American (parents and at least 3/4 four grandparents
   • age >18 years
   • GDM in singleton pregnancy in prior 5 years
   • impaired glucose levels or sum of five OGTT glucose values >625 mg/dl on 75 gram oral glucose tolerance test
   • Fasting plasma glucose <126 mg/dl
   • At least two adult siblings of cousin not known to have diabetes and available for phenotyping; .

2. Siblings and Cousins of GDM Probands

   • Full sibling or first cousin of GDM proband
   • Age >18 yrs
   • Fasting plasma glucose <126 mg/dl.

3. Parents, Uncles and Aunts of GDM Probands

   • Full blooded parent, uncle or aunt of GDM proband

4. Control Proband

   • Mexican American as defined for GDM probands
   • One glucose challenge test result <120 mg/dl at >24 weeks gestation
   • No diabetes in first degree relative
   • Frequency matched to GDM probands by distributions of age, BMI and parity.

5. Spouse of GDM or Control Proband

   • Spouse of GDM proband
   • Age >18
   • At least one child with proband able to provide DNA

6. Child of Proband

   • Child of GDM or control proband and spouse who provided DNA

EXCLUSION CRITERIA

1. PROBANDS (GDM OR CONTROL):

   • Chronic medical illness or medication known to alter glucose/insulin metabolism
   • Current pregnancy or breastfeeding
   • Ilicit drug or alcohol abuse,
   • Inability or unwillingness to give informed consent.

2. SIBLINGS AND COUSINS OF PROBANDS:

   • Chronic medical illness or medication known to affect glucose/insulin metabolism
   • Current pregnancy or breastfeeding,
   • Ilicit drug or alcohol abuse
   • Inability or unwillingness to give informed consent.

3. PARENTS OF PROBANDS

   • Inability or unwillingness to give informed consent.

4. SPOUSE OF GDM or CONTROL PROBAND

   • Inability or unwillingness to give informed consent.

5. CHILD OF GDM or CONTROL PROBAND

   • Lack of parent consent or child assent.

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pancreatic Beta Cell Compensation for Insulin Resistance	Disposition index from intravenous glucose tolerance test	Single time point for primary cohort, repeated 4.5 years later in subset

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Insulin Senstivity	Si from computer modeled intravenous glucose tolerance test	Single time point for primary cohort, repeated 4.5 years later in subset
Acute Insulin Release	Incremental area under insulin curve during first 10 minutes intravenous glucose tolerance test	Single time point for primary cohort, repeated 4.5 years later in subset
Glucose tolerance	normal, impaired or diabetic glucose level determined using American Diabetes Associate criteria applied to glucose levels from a 2-hour, 75 gram oral glucose tolerance test	Single time point for primary cohort, repeated 4.5 years later in subset
Diabetes type 2	Fasting glucose >125 mg/dl and/or 2-hour glucose on 75 gram oral glucose tolerance test >199 mg/dl	Single time point for primary cohort, repeated 4.5 years later in subset
Dietary Intake	Measured by semi-quantitative Harvard Food Frequency Questionnaire	Single time point for primary cohort, repeated 4.5 years later in subset
Physical Activity	Measured by Multi-ethnic Cohort Physical Activity Questionnaire	Single time point for primary cohort, repeated 4.5 years later in subset
Body Fat	Percent body fat measured by dual photon X-ray absorptiometry	Single time point for primary cohort, repeated 4.5 years later in subset
Circulating adipokine levels	Fasting levels of approximately 20 adipocytokines	Single time point for primary cohort, repeated 4.5 years later in subset

Collaborators and Investigators

• Sponsor: University of Southern California
• Collaborators: Kaiser Permanente

Study record dates

Study Major Dates

• Study Start (Actual): July 1, 2001
• Primary Completion (Actual): May 31, 2013
• Study Completion (Actual): May 31, 2013

Study Registration Dates

• First Submitted: September 21, 2017
• First Submitted That Met QC Criteria: September 28, 2017
• First Posted (Actual): October 4, 2017

Study Record Updates

• Last Update Posted (Estimated): November 16, 2023
• Last Update Submitted That Met QC Criteria: November 14, 2023
• Last Verified: November 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Glucose Metabolism Disorders; Metabolic Diseases; Endocrine System Diseases; Hyperinsulinism; Pregnancy Complications; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Diabetes Mellitus; Diabetes Mellitus, Type 2; Insulin Resistance; Diabetes, Gestational
• Other Study ID Numbers: HS 013025

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