A joint symposium of the ADA and the International Society for Pediatric and Adolescent Diabetes (ISPAD) will explore current evidence related to the benefits and the potential drawbacks of early screening to identify type 1 diabetes risk.
Joint ADA/ISPAD Symposium—General Population Screening vs. Targeted Screening for Type 1 Diabetes Risk will be presented from 2:15 p.m. – 4:15 p.m. ET Monday, June 28.
Among the scheduled presenters, Richard A. Oram, MD, PhD, the Diabetes UK Harry Keen Fellow and Associate Professor at the University of Exeter, United Kingdom, will discuss the use of genetic risk scores to direct type 1 diabetes screening.
“Obviously, we know that there is a strong genetic component in type 1 diabetes. In fact, most of the heritable component of type 1 diabetes is measurable by genotyping a handful of SNPs (single nucleotide polymorphisms) from across the genome,” Dr. Oram said. “That’s in contrast to some other diseases, including type 2 diabetes, which is very heritable, but we aren’t yet so fully able to measure that risk with common genetic variants.”
Historically, screening for type 1 diabetes has been focused on antibody testing of family members of people with type 1 diabetes, which is effective but misses a lot of people, Dr. Oram said.
“It’s a good way to identify people at risk of type 1 diabetes, and it’s very easy to measure, but only about 10% of all people with type 1 diabetes have a relative affected,” he explained. “So, if you only study people with a relative affected, you’re only going to study that 10% and 90% won’t be picked up by that method.”
The downside of measuring autoantibodies is determining when to measure them, as they can change over the course of a person’s life, Dr. Oram added
“So, the upside to autoantibodies is they are a fantastic marker associated with the early prediagnosis stages of type 1 diabetes and are critically important to any screening program. But it’s hard to know when you should measure them in the population,” Dr. Oram said. “If we measure autoantibodies very early in life—ages 2 to 5—we may identify the infants who are going to develop type 1 diabetes in early life but miss those who develop autoimmunity after this age. However, if we measure them later on, some infants have already progressed to type 1 diabetes and we’ve missed them, and they are some of the most severe presentations.”
A combined screening structure that includes a genetic risk score may be the answer.
“We think that about 80% of all cases occur in the 10% of children with the highest type of diabetes genetic risk score. So perhaps we could screen infants at birth and pick a subset of the highest risk infants and do sequential antibody monitoring on them,” Dr. Oram said. “Moving forward, we should consider and study whether or not identifying high-risk children at birth and following up that subset is a practical and efficient approach to predicting which infants develop type 1 diabetes.”
Brett McQueen, PhD, Assistant Professor and Director of the Center for Pharmaceutical Value, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, will analyze whether type 1 diabetes screening is cost-effective.
“There is strong evidence suggesting that at least some form of presymptomatic type 1 diabetes in children should be identified early, allowing for timely diagnosis before onset of life-threatening complications, such as diabetic ketoacidosis (DKA),” Dr. McQueen said. “Screening in its current form is quite expensive, and so the debate is whether we do this at a population level with a really broad group of people, knowing full well that type 1 diabetes is a very low prevalence disease relative to others.”
Cost-effectiveness should not be judged solely in the context of upfront costs, Dr. McQueen said, but should be considered an “insurance policy” against the health and economic costs of future diabetes complications.
“We have to think about this as insurance against a really uncertain future for a group of patients who have no idea they are at high risk of developing type 1 diabetes,” he said. “It’s not going to be cost-effective if we’re just talking about DKA events, but it actually might be good value even if we just have modest improvements in glycemic control. By screening and by having efficient monitoring strategies, we could intervene early and really change trajectories of people’s lives in a positive way.”
Also during this symposium, Anette-Gabriele Ziegler, MD, will discuss general population screening for type 1 diabetes risk and presymptomatic type 1 diabetes; Diane K. Wherrett, MD, FRCP, will talk about targeted screening and the TrialNet screening and prevention initiative; and Laura B. Smith, PhD, will discuss psychological aspects of type 1 diabetes risk screening.