Researchers are just beginning to evaluate a wide range of potential environmental and genetic factors in autoimmunity leading to type 1 diabetes, according to Jeffrey Krischer, PhD, Professor of Pediatrics and Internal Medicine at the University of South Florida’s College of Medicine.
Dr. Krischer will moderate the Saturday afternoon symposium Lessons Learned from the Environmental Determinants of Diabetes in the Young (TEDDY) Study—Insights into Early Autoimmune Type 1 Diabetes, which will begin at 1:45 p.m. in room W415B (Valencia Ballroom). The two-hour session is supported by a grant from The Leona M. and Harry B. Helmsley Charitable Trust.
“We will present new findings in Orlando that will change the conversation about type 1 diabetes in youth,” Dr. Krischer said.
TEDDY is the largest and most comprehensive study of events leading to the diagnosis of diabetes in children. The study is following 8,676 children in four countries from birth to 15 years of age who are at elevated risk for type 1 diabetes. The current median age of the study population is nine years, and data collection is ongoing. TEDDY researchers are evaluating the contributions of genetics, environment, and gene-environment interactions from the development of the very first markers of disease to clinical diagnosis of type 1 diabetes.
Saturday’s symposium will begin with a look at the effects of prenatal dietary supplements. The use of prenatal supplements was self-reported when pregnant mothers enrolled in TEDDY, but data collection on the infants was prospective and is continuing.
“We had a very specific question: Was the use of maternal dietary supplements associated with the risk of the child developing future autoimmunity?” said Jill Norris, MPH, PhD, Professor and Chair of Epidemiology at the Colorado School of Public Health. “We looked at supplements containing vitamin D and omega 3 fatty acids because the literature suggested that in pregnancy and in infancy, these two micronutrients would have a role in type 1 diabetes autoimmunity. Nobody has ever done this kind of analysis on this kind of grand scale before.”
Gestational infections are another potential player in the development of islet autoantibodies during infancy. Antibodies to insulin or glutamic acid decarboxylase (GAD65) typically appear first. Insulinoma-associated protein 2 (IA-2) and zinc cation efflux transporter 8 (ZnT8) antibodies may appear later.
“In the past, there have been very conflicting associations between the maternal infections during pregnancy and the risk of type 1 diabetes in the child,” said Kristian F. Lynch, PhD, Assistant Professor of Pediatrics at the University of South Florida Health Informatics Institute. “It’s well known that antibodies appear well before the clinical onset of diabetes. What TEDDY is showing is that there may be different pathways leading to the initiation of antibodies, depending on the type of autoantibodies that appear and in which order they appear.”
The role of infections in the development of islet autoimmunity has been similarly controversial. TEDDY researchers are attempting to unravel links between childhood infection and type 1 diabetes by using a parental logbook of childhood illnesses and by analyzing biosamples collected from children in the study.
“We have already found an association between certain respiratory infections and onset of islet autoimmunity in TEDDY,” said Maria Lönnrot, MD, PhD, from Tampere University Hospital in Tampere, Finland. “The current focus is to see if there is any association between gastrointestinal infections recorded by parents in their diary book with onset of islet autoimmunity. We tend to think that different islet autoantibodies represent different pathways to autoimmunity, so we looked at the association between infections and the appearance of insulin antibodies and GAD65 antibodies because those are usually the first to appear.”
Riitta Veijola, MD, PhD, from Turku University Hospital in Turku, Finland, will discuss early findings on how family history of diabetes and other autoimmune diseases might affect the development of islet antibodies and type 1 diabetes.
The session’s final speaker will present a lecture titled “My Child is Islet Autoantibody Positive—Impact on Parent Understanding of Their Child’s Diabetes Risk.”
“We don’t ever tell parents to change anything because of the appearance of islet antibodies,” said Suzanne Bennett Johnson, PhD, Distinguished Research Professor in Behavioral Sciences and Social Medicine at Florida State University. “But some parents report changes to their child’s diet to promoting what they believe is a healthier diet, often with fewer sweets. We want to get a better idea of how the appearance of islet antibodies affects a parent’s perception of the risk their child may develop type 1 diabetes and how that perception of risk might affect their behavior.”