Screening for thyroid dysfunction in a community population of diabetic patients.

In a general practice population of 11,300 patients, 223 were known to have diabetes mellitus. Thirteen diabetic patients (5.8%) had a previous diagnosis of thyroid disease. The study excluded 17 patients who received sole diabetes care at a secondary referral centre (of whom 5 had a previous diagnosis of thyroid disease), 8 with a previous diagnosis of thyroid disease receiving community care, and 1 patient who declined screening. New thyroid disease was diagnosed in 11 patients (8 female, 3 male): 5 with primary hypothyroidism, 4 with subclinical hypothyroidism, 1 with hyperthyroidism and 1 with subclinical hyperthyroidism. Thus the prevalence of undiagnosed thyroid disease in diabetic patients receiving community diabetes care was 5.5% (9.5% of female patients), and the prevalence of thyroid disease (previously known and diagnosed as a result of screening) in the entire population of diabetic patients registered in the general practice was 10.8%. These findings suggest that screening for thyroid disease should be considered in patients receiving diabetes care in the community.