Endocrine Abstracts

The relationship between coeliac disease and primary hypothyroidism is recognised, however, a less well recognised association exists with secondary hypopituitarism as illustrated by this case.

A 50 year old male was referred with a six month history of altered bowel habit, iron deficiency anaemia and presumed primary hypothyroidism (TSH 15, free T4 <5.0). He had negative investigations for any gastrointestinal blood loss. Duodenal biopsy showed non-specific duodenitis and normal villous architecture. Low-dose thyroxine (25 mcg) exacerbated the patients’ diarrhoea and there was no rise in his haemoglobin with iron supplementation.

On referral he was clinically euthyroid, pulse 84, normal reflexes and no abnormal pigmentation or goitre. Anti-TPO >5000, technetium uptake scan showed low uptake in normal sized lobes. Baseline anterior pituitary function revealed LH 4 U/L (1–6.4) FSH 4.1 U/L (2–8) total testosterone 7.9 nmol/L (10–36) IGF-1 50 øg/L (80–300) Prolactin, 158 mU/L (0–500). These plus the relatively low TSH response to undetectable T4 levels raised the possibility of pituitary dysfunction. Given the clinical presentation plus iron deficiency and endocrine abnormalities the diagnosis of coeliac disease with secondary pituitary dysfunction was considered. Pituitary MRI was normal. His anti-tissue transglutimase antibodies were positive, however anti-endomysial antibodies were negative.Repeat duodenal biopsies revealed sub-total villous atrophy confirming a diagnosis of coeliac disease.

After implementing a gluten-free diet pituitary function was restored with an appropriate response to his primary autoimmune hypothyroidism (TSH rising to 63 and free T4 <5.0) and normal IGF-1 and testosterone levels. The patient remained clinically euthyroid.