Puberty is associated with a marked increase of the female sex predominance in chronic autoimmune thyroiditis.

ABSTRACT

BACKGROUND: Chronic autoimmune thyroiditis (CAT) displays a strong female predominance with female-to-male (FM) ratios of 4-201 in adults and 2-91 in children and adolescents. Both genetic and hormonal factors are involved in this phenomenon. The relation between puberty and FM ratio in CAT has never been evaluated. METHODS: The FM ratio of 133 children with CAT (group A, age at diagnosis 2.4-17.7 years) was compared with that of 113 adult CAT patients (group B, age at diagnosis 21-79 years). Group A included 64 prepubertal (aged 2.4-13.2 years, group A1) and 69 pubertal (aged 9.2-17.4, group A2) children. RESULTS: The FM ratio in group A was 3.0, which is significantly (p < 0.001) lower than that (10.3) found in group B patients. The FM ratio of group A1 prepubertal children was lower (1.6) and significantly different from that of pubertal (6.7, p < 0.01) and adult patients (10.3, p < 0.0001). This phenomenon was more evident in hypothyroid as compared to euthyroid CAT. CONCLUSIONS: This study provides the first evidence that female predominance of CAT strongly increases during puberty, suggesting a major role for sex hormones in this phenomenon. Further studies are needed to clarify this point.