ESPE Abstracts

Background: Anorexia nervosa is usually associated with lower levels of thyroid hormones especially suppressed TSH and T₃ with normal T₄ levels due to the effects of starvation on metabolism. We present two cases where the underlying eating disorder masked the thyroid dysfunction.

Patient 1: 15-year-old girl with anorexia nervosa and BMI of 15.6 was noted to have suppressed TSH<0.1 mU/l, high normal T₃–7.0 pmol/l and normal T₄–17.4 pmol/l suggesting subclinical hyperthyroidism within one month after starting on re-feeding regimen. On examination she had right thyroid nodule. Thyroid peroxidase antibodies were mildly raised at 72.6.Radio-Isotope scan showed good uptake in the right lobe with no uptake in the left lobe. Ultrasound thyroid showed multinodular goitre. She was started on carbimazole. Three months after her initial presentation her thyroid function had normalised with normal thyroid antibody level. Hence carbimazole was stopped and subsequent thyroid function tests have been normal. Hence, the thyroid dysfunction was attributed to her eating disorder. She presented after 2 years with biochemical evidence of hyperthyroidism following relapse of her eating disorder and was restarted on carbimazole.

Patient 2: 16-year-old girl with anorexia nervosa and BMI-15 was noted to have biochemical evidence of autoimmune hypothyroidism on presentation. Her TSH was raised at 44 mU/l, with markedly suppressed T₄–4.9 pmol/ and T₃–2.7 pmol/l. Her thyroid function tests had normalised after starting on thyroxine.

Conclusion: Anorexia nervosa may mask thyroid dysfunction making it difficult to interpret the thyroid function tests.