Prevalence of antithyroperoxidase antibodies in a multiethnic Brazilian population: The ELSA-Brasil Study

ABSTRACT Objective In this study, we aimed to describe the prevalence and distribution of positive antithyroperoxidase antibodies (TPOAb) according to sex, age strata, and presence of thyroid dysfunction using baseline data from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil). Materials and methods Thyroid hormone tests were obtained from each study participant at baseline. Levels of thyroid-stimulating hormone (TSH) and free thyroxine (FT4) were measured using a third-generation immunoenzymatic assay. Antithyroperoxidase antibodies were measured by electrochemiluminescence and were considered to be positive when ≥ 34 IU/mL. Results The prevalence of TPOAb among 13,503 study participants was 12%. Of participants with positive TPOAb, 69% were women. Almost 60% of the individuals with positive TPOAb were white. The presence of positive TPOAb was associated with the entire spectrum of thyroid diseases among women, but only with overt hyperthyroidism and overt hypothyroidism in men. Conclusion The distribution of positive TPOAb across sex, race, age, and thyroid function in the ELSA-Brasil study is aligned with the worldwide prevalence of positive TPOAb reported in iodine-sufficient areas. In women, the presence of TPOAb was related to the entire spectrum of thyroid dysfunction, while in men, it was only related to the occurrence of overt thyroid disease.

Clinical analysis of 32 cases of pituitary hyperplasia secondary to primary hypothyroidism / 中华内分泌代谢杂志

Objective To improve the recognition of pituitary hyperplasia secondary to primary hypothyroidism by analyzing clinical and imaging data. Methods The clinical features, hormone data,imaging findings, and treatment were reviewed in 32 patients with pituitary hyperplasia secondary to primary hypothyroidism in Huashan Hospital from 1999 to 2008. Results Thirty-two patients, most juvenile,presented clinical and imaging features suggestive of functional primary pituitary adenoma. The dose of levothyroxine was increased to maintain the thyrotropin concentration at normal values. Following adequate thyroxine replacement, pituitary hyperplasia regressed on average within 6 months. Conclusions Pituitary hyperplasia secondary to primary hypothyroidism seems to be quite prevalent in children and adolescents.Complete regression will be achieved with thyroxine replacement therapy.