Endocrine Abstracts

Hyperthyroidism is common affecting up to 2% of the UK population and the prevalence is highest in young and middle-aged women. Although patients may have clinical symptoms suggestive of hyperthyroidism, rates of undiagnosed hyperthyroidism range from 0.5 to 1.5%, especially in the elderly. We investigated 3563 UK patients to (i) assess the influence of ageing on clinical signs and symptoms and (ii) identify symptoms and signs indicating hyperthyroidism in different age groups. Patients were divided into quartiles according to age at presentation (877 aged 16–32 year, 878 aged 33–44 year, 926 aged 45–60 year and 882 aged 61–91 year). There was a higher prevalence of males in the older age group compared with younger patients (18; 19; 22; 26% in the respective age groups, P<0.001) and toxic nodular disease was more common in older patients (3; 5; 15; 30%, P<0.001). Younger patients had more severe thyrotoxicosis (median fT4 concentrations 51.7; 43.2; 37.8; 32.4 pmol/l, P<0.001). Weight loss was the most commonly reported symptom and was most prevalent in those aged 45–60 year (55; 57; 62; 57%, P=0.01). Symptoms of palpitations (49; 55; 53; 36%, P<0.001), tremor (53; 56; 55; 37%, P<0.001), anxiety (38; 43; 46; 26%, P<0.001), heat intolerance (53; 55; 57; 37, P<0.001), diarrhoea (21; 25; 24; 13%, P<0.001), neck swelling (30; 24; 15; 13%, P<0.001) and gritty eyes (7; 7; 7; 3%, P<0.001) were less common in older patients. The highest number of asymptomatic patients was found in those aged over 61 (13; 12; 11; 17%, P<0.001) and conversely the lowest number of patients reporting 5 or more symptoms was found in the elderly (29; 33; 32, 13%, P<0.001). Clinical signs of tremor (44; 37; 37; 37%; P=0.004) and goitre (83; 80; 64; 47%; P<0.001) were most prevalent in younger patients and the finding a atrial fibrillation was most common in the elderly (0; 1; 3; 14%; P<0.001). Signs of ophthalmopathy including lid retraction, proptosis and ophthalmoplegia, in those with Graves’ disease, were similarly frequent across all age groups.

Conclusions: We have confirmed that the clinical profile of hyperthyroidism is different in older patients who present with significantly fewer symptoms and signs. We propose that clinicians should adopt a low threshold for performing thyroid function tests in older adults.