Frequency of thyroid disease among Southeast Asian primary care patients.
We prospectively assessed 99 Southeast Asians for the presence of thyroid disease who were attending a primary care clinic devoted to the care of refugees. Subjects were undergoing evaluation as new patients and had no previously diagnosed thyroid abnormality. Each patient had a physical examination performed by his or her primary-care provider, was given a standardized questionnaire that focused on symptoms of thyroid disease and underwent a venipuncture for total thyroxine, triiodothyronine resin uptake and thyrotropin (TSH) concentration. Those who had an abnormal examination, calculated free thyroxine index (FT4I) or TSH level were re-examined by an endocrinologist and had repeat thyroid studies performed. Although 81% of patients reported > or = 1 symptom compatible with thyroid dysfunction, only 17% were found to have laboratory abnormalities. An abnormal FT4I and TSH level was found in 5% and 13% of subjects, respectively, but only one case of clinically significant hyperthyroidism and no cases of hypothyroidism were confirmed. TSH suppression, noted in 12% of subjects, persisted over a median follow-up of 6 months. Among seven patients with an anatomic abnormality of the thyroid, four had an abnormal FT4I or TSH. We conclude that the clinical prevalence of symptomatic thyroid dysfunction among Southeast Asians is comparable to that reported for non-Asian populations, but that the frequency of subclinical hyperthyroidism may be higher. Although symptoms suggestive of thyroid disease are common, routine screening for thyroid disease is not indicated in this study.