Study Highlights Prevalence of Comorbid Autoimmune Diseases, T1D in Pediatric Populations

In recent years, the number of children diagnosed with additional autoimmune diseases accompanying type 1 diabetes (T1D) has increased, according to a study published in Frontiers in Endocrinology.

It is estimated that 1,110,100 young people under the age of 20 currently have T1D worldwide, while T1D incidence in children increases by 2% to 5% annually. Incidence rates (IRs) of pediatric T1D vary by region and are usually low in Asian countries and higher in European countries.

In addition, over the past 30 years research has shown frequency of autoimmune diseases in general has increased significantly. The global prevalence of autoimmune diseases in pediatric patients is roughly 5% and is most frequently represented by autoimmune thyroid diseases (AITDs), authors wrote. “Additional autoimmune diseases (AADs) frequently occur in the same individual over the course of T1D, suggesting strong shared genetic susceptibility and pathological mechanisms,” they said.

To assess the prevalence of onset autoimmune illnesses since T1D diagnosis in children, researchers conducted a 9-year retrospective study.

The study population consisted of 493 children and adolescents, between ages 0 and 18 (264 boys and 229 girls). All participants were diagnosed with T1D between 2010 and 2018 at a medical university in Poland. Patients were divided into age groups: 0-4 years, 5-9 years, 10-14 years, and 15-18 years.

Of the patients included, median age (interquartile range) of T1D diagnosis was 9.5 years (5.5-12.5).

Based on data obtained from medical records, researchers found:

• Annual standardized IR of T1D increased from 19.2/100,000 in 2010 to 31.7/100,000 in 2018 (1.7-fold), with an increase in the incidence rate ratio (IRR) of 4% per year
• The highest growth in T1D IR was recorded in 5- to 9-year-olds (from 19.61/100,000 in 2010 to 43.45/100,000 in 2018)
• 61 patients (12.4%) were diagnosed with at least one additional autoimmune disease during the study period
• Autoimmune disease prevalence doubled from 10.4% in 2010 to 20.8% in 2018
• Autoimmune thyroid illnesses were found in 37 children (7.5%); incidence increased from 6.3% in 2010 to 12.5% in 2018
• 26 children (5.3%) were diagnosed with celiac disease; prevalence increased from 4.2% to 9.8% in the study period
• Prevalence of additional autoimmune thyroid disease was higher in patients with glutamic acid decarboxylase–positive antibodies (χ² = 3.4, P = .04), the oldest age group (15-18 years) (χ2 =7.1, P = .06), and female patients (χ² =7.1, P = .007)

Increased and multiple autoimmunity in young patients with T1D may be due to a variety of factors including a common genetic background, defective immunoregulation, environmental triggers, alteration of gut microbiota balance, and epigenetic changes induced by air pollutants. The increase in autoimmune diseases also coincides with rising prevalence of youth obesity.

Improved diagnostic methods such as ultrasonography of thyroid glands throughout the study period may have influenced the study’s findings, marking a limitation. As such, future analyses of the data are required to fully identify factors that may be responsible for the observed phenomenon, authors concluded.

Reference

Głowińska-Olszewska B, Szabłowski M, Panas P, et al. Increasing co-occurance of additional autoimmune disorders at diabetes type 1 onset among children and adolescents diagnosed in years 2010-2018—single-center study. Front Endocrinol. Published online August 6, 2020. doi:10.3389/fendo.2020.00476