Association between thyroid autoimmunity and Helicobacter pylori infection

There have been controversial reports linking infection to autoimmune thyroid disease (AITD). However, data regarding the relationship are limited for Asian populations, which have an extremely high prevalence of infection. We performed this study to investigate the association between infection and AITD in Koreans. This study involved adults aged 30 to 70 years who had visited a health promotion center. A total of 5,502 subjects were analysed. Thyroid status was assessed by free thyroxine, thyroid stimulating hormone, and anti-thyroid peroxidase antibody (TPO-Ab). Immunoglobulin G (IgG) antibodies to were measured as an indication of infection. We compared the prevalence of TPO-Ab in subjects with and without infection. IgG antibodies were found in 2,875 subjects (52.3%), and TPO-Ab were found in 430 (7.8%). Individuals positive for Ab were older than those negative for Ab ( < 0.01). The proportion of females was significantly higher in the TPO-Ab positive group (41.0% vs. 64.2%, < 0.01). Prevalence of TPO-Ab positivity was higher in subjects with infection (8.6% vs. 7.00%, = 0.03), and this association was significant after adjusting for age, sex, and body mass index (odds ratio, 1.02; 95% confidence interval, 1.00 to 1.03; = 0.04). In our study, prevalence of TPO-Ab positivity is more frequent in subjects with infection. Our findings suggest infection may play a role in the development of autoimmune thyroiditis.