Endocrine Abstracts

Objective

To determine predictive factors of co-existing autoimmunity in children with type 1 diabetes mellitus (T1D).

Material and methods

64 children with combined autoimmune pathology (T1D and autoimmune thyroid diseases or celiac disease) - main group, age 12.14±3.54 years) and 81 patients with only T1D (comparison group, age 11.57±3.34 years) were recruited. Groups were comparable in age (P = 0.34) and T1D duration (P = 0.81). Assessment of anthropometric parameters; biochemical blood parameters; glycosylated hemoglobin (HbA1c), vitamin D, thyroid hormones, antibodies to thyroid peroxidase (anti-TPO), glutamate decarboxylase (GAD) and zinc transporter8 (ZnT8) 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 44 children had combinations of T1DM with autoimmune thyroiditis (AIT), 15 - celiac disease (CD), 3 – Graves’ disease, 1 – AIT and CD. Children with T1D and autoimmune thyroid diseases had significantly higher z-scores of BMI (+0.24 vs -0.19, P = 0.019) and the prevalence of overweight (26.5 vs 12.0%, P = 0.029) than the comparison group. Children with concomitant thyroid diseases demonstrated higher triglycerides (P = 0.032) and very low density lipoproteins (P = 0.038) compared to the comparison group. Among the risk factors for autoimmune thyroid damage, the association of thyroid pathology with severe vitamin D deficiency (level <10 ng/ml) (χ2 = 6.848, P = 0.009, odds ratio (OR) 3.57, 95% confidence interval (CI) 1.07–5.46), female gender (OR 3.08, CI 1.48–6.36), GAD antibodies (OR 5.13, CI 1.23–21.35) and ZnT8 antibodies (OR 5.13, CI 1.23–21.35) was detected. Children with concomitant thyroid diseases and severe vitamin D deficiency had higher risk of diabetes decompensation (HbA1c>9%) compared with the patients with vitamin D concentration > 10 ng/ml (χ² 6.848; OR 7.00; CI 1.50–32.72, P = 0.011). Association of CD with early (less than 4 years old) T1D onset (χ²= 8.250; OR 7.022; CI 2.22–22.20, P = 0.003) and severe vitamin in D deficiency was established (OR 9.82; CI 5.27–17.34, P = 0.001).

Conclusions

1. Higher levels of HbA1c were detected in children with polyglandular autoimmune pathology and severe vitamin D deficiency.

2. Higher risk of autoimmune thyroid disease was found in patients with severe vitamin D deficiency, high levels of GAD ant ZnT8 antibodies, female gender and late puberty. Among the risk factors of CD early onset of T1D and severe vitamin D deficiency was detected.