Natural History Study of the Development of Type 1 Diabetes

RATIONALE

The accrual of data from the laboratory and from epidemiologic and prevention trials has improved the understanding of the etiology and pathogenesis of type 1 diabetes mellitus (T1DM). Genetic and immunologic factors play a key role in the development of T1DM, and characterization of the early metabolic abnormalities in T1DM is steadily increasing. However, information regarding the natural history of T1DM remains incomplete. The TrialNet Natural History Study of the Development of T1DM has been designed to clarify this picture, and in so doing, will contribute to the development and implementation of studies aimed at prevention of and early treatment in T1DM.

Purpose:

TrialNet is an international network dedicated to the study, prevention, and early treatment of type 1 diabetes. TrialNet sites are located throughout the United States, Canada, Finland, United Kingdom, Italy, Australia, and New Zealand. TrialNet is dedicated to testing new approaches to the prevention of and early intervention for type 1 diabetes.

The goal of the TrialNet Natural History Study of the Development of Type 1 Diabetes is to enhance our understanding of the demographic, immunologic, and metabolic characteristics of individuals at risk for developing type 1 diabetes.

The Natural History Study will screen relatives of people with type 1 diabetes to identify those at risk for developing the disease. Relatives of people with type 1 diabetes have about a 3 to 4 percent chance of being positive for the antibodies associated with diabetes. TrialNet will identify adults and children at risk for developing diabetes by testing for the presence of these antibodies in the blood. A positive antibody test is an early indication that damage to insulin-secreting cells may have begun. If this test is positive, additional testing will be offered to determine the likelihood that a person may develop diabetes. Individuals with antibodies will be offered the opportunity for further testing to determine their risk of developing diabetes over the next 5 years and to receive close monitoring for the development of diabetes.

The Natural History Study is conducted in two parts:

• Screening
• Monitoring (annual and semi-annual depending on risk)

In Screening , a simple blood test is done to screen for the presence of diabetes-related biochemical autoantibodies (GAD, IA-2A, mIAA). Islet cell autoantibodies (ICA) are also measured in individuals positive for one or more biochemical autoantibodies. Participants can go to a TrialNet Clinical Center, Affiliate, or request a screening kit to have their blood drawn by a local physician or laboratory. Participants will be provided with their screening results within 4-6 weeks.

If autoantibodies are present initially and are confirmed by repeat testing, participants will be invited to have additional testing in baseline monitoring visit to determine their average risk of developing diabetes over the next 5 years. The baseline monitoring visit will include an Oral Glucose Tolerance Test (OGTT), re-testing for biochemical and islet cell autoantibodies if needed, measurement of HbA1c, and HLA (genetic) typing.

Individuals with less than 3% average risk will be asked to come for follow-up on annual basis; individuals with greater than average 32% risk will be asked to come for follow-up visits on semi-annual basis.

Participants will be monitored for possible progression towards type 1 diabetes and may be offered the opportunity to enter into a prevention study such (e.g., Oral Insulin prevention study) or an early treatment study if they are diagnosed with type 1 diabetes while participating in the Natural History Study.

First and second/third degree relatives of individuals with type 1 diabetes.

• [No authors listed] Effects of insulin in relatives of patients with type 1 diabetes mellitus. N Engl J Med. 2002 May 30;346(22):1685-91.
• Gale EA, Bingley PJ, Emmett CL, Collier T; European Nicotinamide Diabetes Intervention Trial (ENDIT) Group. European Nicotinamide Diabetes Intervention Trial (ENDIT): a randomised controlled trial of intervention before the onset of type 1 diabetes. Lancet. 2004 Mar 20;363(9413):925-31.
• Atkinson MA, Eisenbarth GS. Type 1 diabetes: new perspectives on disease pathogenesis and treatment. Lancet. 2001 Jul 21;358(9277):221-9. Review. Erratum in: Lancet. 2001 Sep 1;358(9283):766.
• Verge CF, Gianani R, Kawasaki E, Yu L, Pietropaolo M, Jackson RA, Chase HP, Eisenbarth GS. Prediction of type I diabetes in first-degree relatives using a combination of insulin, GAD, and ICA512bdc/IA-2 autoantibodies. Diabetes. 1996 Jul;45(7):926-33.
• Bingley PJ, Christie MR, Bonifacio E, Bonfanti R, Shattock M, Fonte MT, Bottazzo GF, Gale EA. Combined analysis of autoantibodies improves prediction of IDDM in islet cell antibody-positive relatives. Diabetes. 1994 Nov;43(11):1304-10.

Inclusion Criteria:

• Individuals 1 to 45 years old who have an immediate family member with type 1 diabetes (such as a child, parent, or sibling)
• Individuals 1-20 years old who have an extended family member with type 1 diabetes (such as a cousin, niece, nephew, aunt, uncle, grandparent, or half-sibling)

Exclusion Criteria:

To be eligible a person must not:

• Have diabetes already
• Have a previous history of being treated with insulin or oral diabetes medications.
• Currently be using systemic immunosuppressive agents (topical and inhaled agents are acceptable)
• Have any known serious diseases

• National Institute of Allergy and Infectious Diseases (NIAID)
• Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD)
• National Center for Research Resources (NCRR)
• Juvenile Diabetes Research Foundation
• American Diabetes Association