Thyroid disorders in Khulna district: a community based study.

This study reports the prevalence of thyroid diseases and their relationship to autoimmunity in a population of Khulna district where goitre is not endemic. A survey was performed among citizens of a union of Khulna district. The study population consisted of a random sample of the students of primary schools, secondary schools and people of nearby areas. History taking, neck examination for goitre and blood examination for thyroid hormones was done from each subject. Blood sample was measured for thyroid hormones and thyroid microsomal antibody (TMAb) using radioimmunoassay method. Of the total 925 individual studied, 527 was female and 398 was male with age ranges from 2-62 years (mean 19.86 +/- 13.62 years). The overall occurrence of thyroid disease was estimated to be 20.43%. The spectrum of thyroid disorders showed highest incidence of diffuse goitre (7.35%), followed by sub-clinical hypothyroidism (6.59%), hypothyroidism (4.97%), hyperthyroidism (0.86%) and sub-clinical hyperthyroidism (0.65%). The incidence of thyroid disorders was observed to be highest in the 11-45 years age group (79.89%). Female outnumbered male, the ratio being 2.5:1 with preponderance of female subjects in all disease groups. The prevalence of all goitre was 10.49%. TMAb estimation was performed in 318 samples, of them 48 cases (15.09%) was found to be autoimmune thyroid disease. Of the total sub-clinical and overt hypothyroidism, the incidence of autoimmune thyroid disease was 29.29% and non-goitrous thyroid dysfunction was more common than goitrous one. Three of 38 (7.89%) euthyroid goitrous subjects showed positive antibody. Interestingly, 16 of 181 (8.84%) individual had a positive antibody, which was considered normal by neck examination. Goitre prevalence of 10.49% in this study indicates the region to be a mild iodine deficient area. Chronic autoimmune disease is likely to be one of the etiological factors for thyroid disorders in this southern zone.