Endocrine Abstracts

Aims: To assess the relationship between thyroid peroxidase (TPO) antibodies and the development of thyroid disorders in children with type 1 diabetes mellitus (T1DM).

Method: TPO antibody status and duration of diabetes at diagnosis of thyroid disorder were cross-sectionally examined in all children attending the Oxford T1DM service (n=342, male:female ratio 1:0.8).

Results: Twenty patients were identified with thyroid comorbidity, representing 5.9% of the clinic; with a female preponderance – M:F ratio 1:6. Most patients had hypothyroidism (90%, n=18) with 10% (n=2) having hyperthyroidism. In one patient the thyroid diagnosis predated the T1DM diagnosis by 5.6 years. She was discounted from further analysis, as were three patients in whom TPO antibody status at diagnosis of T1DM was unknown.

For the remaining patients (n=16) TPO antibody status at the time of diagnosis with T1DM was positive in n=7. In this group the duration from diagnosis of T1DM to developing thyroid disorders was 0–4.7years (mean 1.4), compared to 0.04–11.9 years (mean 8.1) in those with negative TPO antibodies at T1DM diagnosis (n=9). The P value was significant at 0.0005.

Most patients who developed thyroid disorders (n=16) were in the pubertal age range: 10–15 years – median age 11.5 years. This is likely to coincide with the onset of puberty.

Conclusion: Positive TPO antibodies at diagnosis in children with T1DM is associated with a significantly earlier onset of thyroid disease. This may warrant closer monitoring of symptoms, and increased biochemical monitoring if clinically indicated. Consistent with observations in non-diabetic populations, there is a higher incidence of thyroid disease in girls with T1DM, particularly around the time of puberty.