Background: 8-27% of general population exhibits low level of thyroid autoantibodies. This study investigated the relationship between microsomal antibody and age, sex, thyroid volume, thyroid hormone values in normal euthyroid subjects.
Methods and designs:
This study is retrospective, cross-sectional with chart review study. All patients with self reports neck enlargement visit endocrinologist clinics for thyroid evaluation to the Chung Shan Medical University Hospital, Taichung, Taiwan, between July 2009 to September 2012 were included. All criteria must be achieved to include in this study include: (i) normal thyroid appearance examined with thyroid ultrasonography; (ii) euthyroid status (iii) no underlying thyroid disease such as thyroid carcinoma, thyroid nodules, thyroid cysts, autoimmune thyroiditis or subacute thyroiditis. Basic demographic information including age, gender, thyroid volume, free T4, TSH, T3, microsomal antibody and TSH receptor antibody were collected.
All subjects were classified into two groups according to presence of thyroid microsomal antibody in normal euthyroid patients, including 488 subjects with negative microsomal antibody and 37 subjects with positive microsomal antibody. Subjects with positive thyroid microsomal antibody had significant larger thyroid volume (p<0.05). Female also showed significantly higher frequency of serum microsomal antibody compared with male. However, no significant correlation was found between thyroid microsomal antibody with age, free T4, T3, TSH, and TSH receptor antibody.
The subjects with presence of microsomal antibody showed higher thyroid volumes, and this autoantibody is more common in woman than in man.