BES2005 Poster Presentations Thyroid (33 abstracts)
1Division of Primary Care, Public and Occupational Health, University of Birmingham, Birmingham, UK; 2Division of Medical Sciences, University of Birmingham, Birmingham, UK. 3School of Life and Health Sciences, University of Aston, Birmingham, UK
Thyroid dysfunction is common, particularly in the elderly, and has an important impact on morbidity and mortality, especially in this age group.
Aim: We have investigated associations between thyroid function, presence of atrial fibrillation and cognitive function in a large general practice-based study conducted from December 2002-November 2004. Subjects with a previous history of thyroid disease or currently taking thyroxine or anti-thyroid drugs were excluded. We report a preliminary analysis of the data concerning the proportion of subjects with abnormal TSH (measured using a sensitive assay) and fT4 values.
Method: 5784 subjects aged 65 or over had TSH and fT4 measurements performed. The mean age of subjects was 73.5 years; 49.3% male (mean age 73.3), 50.7% female (mean age 73.7). Reference ranges for TSH were 0.4-5.5mU/l and fT4 9-20 pmol/l
Results: Overall, 2.6% of subjects had low serum TSH (0.7% undetectable [<0.1 mU/l], 1.9% detectable but below reference range [>0.1<0.4mU/l]). High serum TSH values were found in 3.3% (2.4% >5.5 <10 mU/l; 0.9% >10mU/l). The mean serum fT4 was 9.5 pmol/l among the 53 with a serum TSH 10 or higher and of these 23 had fT4 values below the reference range. The mean serum fT4 was 13.0 pmol/l among the 136 with a serum TSH in the range >5.5<10; all had fT4 values within the reference range. Among those with detectable TSH, 13 had high fT4 values with a mean of 18.8 pmol/l. Among those with low but detectable TSH mean fT4 was 15.5 pmol/l; 6 of these had fT4 above the reference range but none >22.6 pmol/l.
Conclusion: in this the largest UK based study of community living subjects of 60 years and over we have demonstrated that a high proportion have both hypothyroidism and hyperthyroidism, especially subclinical disease.