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Insulin Secretory Defects in Pima Indians at High Risk for NIDDM

NCT00410800 · Status: COMPLETED · Type: OBSERVATIONAL · Enrollment: 310

Last updated 2017-07-02

No results posted yet for this study

Summary

The Pima Indians have the highest reported prevalence of NIDDM of any population in the world. Within this population, it is possible to identify subgroups of individuals at a particularly high risk for NIDDM. This project examines whether defects in insulin secretion contribute to the higher risk of NIDDM in these subgroups and whether they progress over the course of the disease.

Healthy Pima men and women at high risk for NIDDM including individuals in the following 3 groups will be recruited: 1)persons whose mothers and/or father developed diabetes at an early age (\< 35 y); 2) persons whose mothers were diabetic during pregnancy; and 3) persons whose birthweight was \< 2500 g. These individuals, as well as subjects with none of the above risk factors and a group of non-Pima controls, will be admitted to the NIH Clinical Research Unit at Phoenix Indian Medical Center for the following series of studies. Body composition will be determined by DXA scanning and by measuring the amount os visceral abdominal fat using MRI. A 75-g oral glucose tolerance test and a 25-g intravenous glucose tolerance test will be performed. Insulin action will be measured with a hyperinsulinemic-euglycemic glucose clamp (insulin infusion: 40mU/m(2) min and insulin secretory responses to glucose will be measured during a 5-step hyperglycemic glucose clamp immediately thereafter. Pima subjects will be followed longitudinally after discharge from the unit and oral glucose tolerance tests will be performed every three months. Individuals who transition from normal to impaired glucose tolerance or impaired glucose tolerance to diabetic will be invited back to the Clinical Research Center for repeat testing.

By comparing insulin secretion-glucose dose-response curves, it may be possible to discern subtle defects in insulin secretion predisposing certain individuals to NIDDM. In addition, comparison of the responses in the offspring of diabetic pregnancies with those in the offspring of mothers who subsequently became diabetic may allow us to separate defects due to genetic causes from those due to the intrauterine environment. Finally, studying subjects as they progress from normal glucose tolerance to diabetes will test whether the defects in insulin secretion are progressive and contribute to the development of NIDDM.

Conditions

  • NIDDM

Sponsors & Collaborators

  • National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

    lead NIH

Eligibility

Min Age
18 Years
Max Age
65 Years
Sex
ALL
Healthy Volunteers
No

Timeline & Regulatory

Start
1996-08-19
Completion
2011-08-16

Countries

  • United States

Study Locations

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT00410800 on ClinicalTrials.gov