ESPE Abstracts

Background and Aims: The incidence and prevalence of childhood type 1 diabetes (T1D) increases all over the world. The disease is often combined with other autoimmune lesions. The most common is autoimmune thyroid diseases. The combination of several autoimmune diseases significantly worsens diabetes control in children with T1D. The aim of the study: to identify risk factors of autoimmune thyroid diseases in children with T1D based on the study of the features of anthropometric, metabolic and immunological parameters in children with polyglandular autoimmunity.

Methods: 49 children with combined autoimmune pathology (main group, age 12.64±3.68 years) and 81 patients with only T1D (comparison group, age 11.82±3.41 years) were recruited. Groups were comparable in age (P = 0.09) and T1D duration (P = 0.99). Assessment of anthropometric parameters; glycosylated hemoglobin (HbA1c), vitamin D, thyroid hormones, antibodies to thyroid peroxidase (anti-TPO), and zinc transporter8 (ZnT8A) levels was carried out. The assessment of height and body mass index (BMI) was carried out using the z-criterion (who, 2007). Results were processed using Excel 10.

Results: In the main group girls predominated (69.4%). In 46 children T1D coexisted with autoimmune thyroiditis and in 3 patients - with Graves ’ disease. The odds ratio (OR) of developing thyroid pathology in puberty patients was 2.381; 95% confidence interval (95% CI) 1.341-3.438; in girls – OR 3.076, 95% CI 1.487-6.362. We found higher BMI z-criteria in the main group (P = 0.019) and a greater prevalence of overweight (26.5%) compared to patients with only T1D – 12.3% (P = 0.029). There was a tendency to lower vitamin D levels in the main group compared to the comparison group (15.62±8.82 ng/ml vs 18.08±6.67 ng/ml, P = 0.12). A higher frequency of severe vitamin D deficiency (<10 ng/ml) was noted in the children with combined endocrinopathy than in the comparison group (27.3% vs. 7.5%; OR=3.566; 95% CI 1.066-5.464, P = 0.009). The patients of the main group with severe vitamin D deficiency were more likely in having poor glycemic control (glycated hemoglobin > 9%) compared to patients with vitamin D concentration > 10 ng/ml (OR = 7.00; 95% CI 1.496-32.721, P = 0.011). The main group showed higher levels of ZnT8A than the comparison group (643.52±771.88 vs 334.43±507.84 U/ml, P = 0.018). A higher prevalence of ZnT8A>1500 U/ml was found in patients with thyroid pathology (OR=3.502, 95% CI 1.223-10.032, P = 0.019).

Conclusion: Female gender, puberty, overweight, severe vitamin D deficiency, high level of ZnT8A were identified as the risk factors of autoimmune thyroid diseases in children with T1D.