Siblings of Children With Type 1 Diabetes Face More Than 10 Times the Risk of Developing the Disease

A study described as Korea’s first and largest of its kind found that siblings of children and adolescents with type 1 diabetes face more than 10 times the risk of developing the disease compared with children in the general population.

The Korea Disease Control and Prevention Agency’s National Institute of Health announced the results of a multicenter collaborative study on the familial occurrence and clinical characteristics of type 1 diabetes in children and adolescents on the 13th.

Supported by the National Institute of Health and led by Seoul National University Bundang Hospital, the study included 936 patients aged 18 years or younger who were diagnosed at 18 university hospitals in Korea from 2010 to 2024.

The study found a family history of type 1 diabetes in 32 patients, or 3.4% of the total, including cases in parents or siblings. Parents had the disease in 1.1% of cases.

In particular, an analysis of 779 siblings of the patients found that 23 (3.0%) had developed type 1 diabetes. This rate is more than 10 times the incidence of 0.26% in the general pediatric population in Korea.

Both twins developed the disease in three of seven twin pairs, for a concordance rate of 42.9%.

Patients diagnosed second within a family had lower blood glucose and glycated hemoglobin levels at diagnosis than those diagnosed first, and a significantly lower rate of diabetic ketoacidosis, an acute complication.

The researchers said that greater awareness of the disease because another family member had been diagnosed first may have contributed to earlier detection in subsequent patients.

Jae-hyun Kim, a professor in the Department of Pediatrics at Seoul National University Bundang Hospital, said, "This study has substantial public health value because it identified the incidence of type 1 diabetes in Korean children and adolescents according to family history and quantified the specific risk for their siblings." He added, "It suggests that a new paradigm shift may be possible, in which type 1 diabetes, too, can be prevented before pancreatic dysfunction develops."

Won-ho Kim, director of the Department of Chronic Disease Convergence Research at the National Institute of Health, said, "This is the first case in Korea to identify siblings as a high-risk group." He added, "We will establish a national registry for diabetes in children and adolescents and continue research to generate scientific evidence suited to conditions in Korea."