Endocrine Abstracts

The thyroid gland undergoes several anatomical changes with age and both overt and subclinical thyroid dysfunction a more prevalent in elderly patients. Recent reports have convincingly shown a physiological rise in serum TSH concentrations in the elderly and studies on autoimmunity have indicated an age-related prevalence of antithyroid antibodies. Interpreting thyroid function tests in elderly patients may be complicated by an increased prevalence of co-existing chronic diseases and the use of medication, which may affect laboratory tests.

We have recently demonstrated significantly reduced prevalences of symptoms and signs of overt hyperthyroidism in older patients with hyperthyroidism, independent of the underlying disease aetiology and the biochemical disease severity, indicating that diagnosing hyperthyroidism in the elderly represents a challenge. Since both subclinical and overt hyperthyroidism are associated with a number of negative outcomes including increased cardiovascular risk, reduction in bone density and decline in cognitive function, it is important to diagnose and treat hyperthyroidism in a timely fashion. A number of age-related factors may also influence the choice of treatment modality to be employed. Despite a physiological age-related increase in serum TSH, hypothyroidism is more prevalent when comparing older adults with younger individuals. Whilst there is clear evidence that significantly raised serum TSH concentrations in association with below normal concentrations of free T₃ and T₄ are associated with significant cardiovascular morbidity and mortality, the treatment of subclinical thyroid dysfunction in the elderly remains controversial. Paradoxically, recent evidence has demonstrated mildly raised serum TSH concentrations in subjects with extreme longevity and the question whether to treat mild hypothyroidism in the elderly remains unanswered.

In view of our ageing population it is important to consider challenges posed by diagnosing and managing thyroid dysfunction in the elderly and these will be addressed in this symposium.