ESPE Abstracts

Background: Graves’ Disease (GD) is the most common cause of hyperthyroidism in children and develops because of stimulation of the thyroid gland by TSH receptor auto-antibodies (TSHR Ab). An increased risk of obesity has been described in both adults and children following initiation of anti-thyroid drug (ATD) therapy but the longer term impact of GD and it’s treatment on physique in children is unclear.

Aims: To assess the BMI of children from 2 tertiary centres in the UK after the first year of treatment and on completion of growth.

Methods: Retrospective case review (2010-2022) of children and young people with GD (positive TSHRAb titres) seen in two paediatric centres in England. Electronic records assessed for thyroid function, height and weight (at diagnosis, 12 months post-diagnosis and most recent). Patients were excluded if pertinent data was not available at diagnosis or 12 months post ATD initiation. Values given are median (range).

Results: 73 patients were assessed (19M: 54F). Age at diagnosis was 13 years (3-17) and age at most recent assessment 16 years (7-22). Patients were White British (n= 48, 65%), Asian (n=17, 23%), Black (n=6, 8%) and mixed race (n=1, 1%). Time to TSH normalisation was 7 months (1.3-43). The duration of follow up was 3 years (1-12). Most children (81%, n=58) received dose titration anti-thyroid drug (ATD) and 18% (n=13) received block and replace. 19 patients remitted off ATD. 3 (4%) received Radio-Iodine and 21 (29%) received thyroidectomy as definitive treatment. 41% (n=30) remain on ATD. The BMI SDS at initial assessment was 0.04 (-4.6-3.5) which was significantly lower (p < 0.05) than at 12 months post diagnosis (median 0.6, range -2.74-3.78) and the most recent assessment BMI SDS 0.7 (-3.6-3.9). There was no difference between 12 months post ATD start and most recent BMI SDS (P> 0.05). Importantly, median BMI SDS remains within normal range throughout follow-up. 11/73 patients were overweight/obese (BMI > 2.0) at final assessment, 8 (73%) of whom were > 14 years at diagnosis and 2 (18%) who had other conditions predisposing to obesity including Trisomy 21.

Conclusions: We show that although BMI SDS increases from diagnosis through to final height assessment, most excessive weight gain occurs at an early stage and most young people achieve a normal BMI SDS at near adult height (NAH). The risk of sustained excess weight is higher in adolescents who have achieved NAH at diagnosis vs younger children.