Thyroid dysfunctions and sonographic characteristics in northern Turkey: a population-based study

BACKGROUND AND OBJECTIVES: In this study, it was aimed to investigate thyroid functions, sonographic characteristics of thyroid gland, relation of thyroid functions, and cardiovascular risk factors in adult population living in northern Turkey. DESIGN AND SETTINGS: The study was conducted in 70 areas (12 urban and 58 rural) in the province of Tokat in northern Turkey from 2005 to 2006. PATIENTS AND METHODS: The study included about 530 000 inhabitants of 18 years and older. Demographic characteristics and thyroid sonographic findings were noted for each subject, and blood samples were collected for measuring serum lipids and thyroid function tests. RESULTS: A total of 1095 subjects (541 males, 554 females) were included, and their mean age (SD) was 41.4 (17) years. Mean thyrotropin (TSH) and free T4 levels (SD) were 1.5 (1.6) μIU/mL and 1.2 (0.1) ng/dL, respectively, in males, and 2.2 (6.6) μIU/mL and 1.2 (0.3) ng/dL, respectively, in females (P<.05). According to mean TSH levels, the prevalence of overt hypothyroidism, overt hyperthyroidism, subclinical hypothyroidism, and subclinical hyperthyroidism was detected as 1.6%, 0.5%, 2.7%, and 4.9%, respectively. Nodular goiter, multinodular goiter, and thyroid heterogeneity were determined as 13.8, 32.1, and 15.6%, respectively. The correlation between cardiovascular risk factors and serum TSH levels was not statistically significant (P>.05). The age was independently and significantly associated with serum TSH levels (P<.0001). CONCLUSION: In terms of high prevalence of thyroid dysfunction and nodular goiter, thyroid diseases must be concluded as a public health problem, and accurate and effective strategies must be identified.