Incidence of thyroid diseases: Results from the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil)

Arch Endocrinol Metab. 2021 Nov 3;65(4):468-478. doi: 10.20945/2359-3997000000348. Epub 2021 Apr 12.


Objective: To evaluate incidence of subclinical and overt hyperthyroidism and hypothyroidism.

Methods: The Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) is a prospective cohort study of 15,105 civil servants, examined at baseline and over a 4-year follow-up. This analysis included 9,705 participants with normal thyroid function at baseline, follow-up information about thyroid function and with no report of using drugs that may interfere in the thyroid function. Thyroid function was defined by TSH/FT4 levels or routine use of thyroid hormones/anti-thyroid medications. Annual and cumulative (over 4-year) incidence rates were presented as percentages (95% Confidence Intervals).

Results: The incidence of all overt and subclinical thyroid disease was 6.7% (1.73%/year): 0.19% for overt hyperthyroidism (0.048%/year), 0.54% for subclinical hyperthyroidism (0.14%/year), 1.98% for overt hypothyroidism (0.51%/year), and 3.99% for subclinical hypothyroidism (1.03%/year). The incidence of all thyroid diseases was higher in women, when compared to men, with a low women:men ratio (1.36). For Blacks the highest incidence was for overt hyperthyroidism, while for Whites, the highest incidence was for overt hypothyroidism. However, the highest incidence of overt hyperthyroidism was detected in Asian descendants. The presence of antithyroperoxidase antibodies at baseline was associated with higher incidence of overt thyroid diseases.

Conclusion: These results showed a high incidence of hypothyroidism, which is compatible with a country with a more-than-adequate iodine intake. The low women:men ratio of the incidence of thyroid dysfunction highlights the importance of the diagnosis of thyroid diseases among men in Brazil.

Keywords: Overt thyroid diseases; hyperthyroidism; hypothyroidism; incidence; subclinical thyroid diseases.

MeSH terms

  • Adult
  • Brazil / epidemiology
  • Female
  • Humans
  • Hyperthyroidism* / epidemiology
  • Incidence
  • Longitudinal Studies
  • Male
  • Prospective Studies
  • Thyroid Diseases* / epidemiology
  • Thyrotropin


  • Thyrotropin

Grants and funding

the ELSA-Brasil baseline study and the 4-year follow-up was supported by the Brazilian Ministry of Health (Science and Technology Department) and the Brazilian Ministry of Science and Technology ( Financiadora de Estudos e Projetos and CNPq National Research Council) (grants of baseline 01 06 0010.00 RS, 01 06 0212.00 BA, 01 06 0300.00 ES, 01 06 0278.00 MG, 01 06 0115.00 SP, 01 06 0071.00 RJ; grants of 4-year follow-up 01 10 0643-03 RS, 01 10 0742-00 BA, 01 12 0284-00 ES, 01 10 0746-00 MG, 01 10 0773-00 SP, 01 11 0093-01 RJ). (grants follow-up 01 10 0643-03 RS; 01 10 0742-00 BA; 01 11 0093-01 RJ; 01 12 0284-00 ES; 01 10 0746-00 MG; 01 10 0773-00 SP). FAPESP – Fundação de Amparo à Pesquisa do Estado de São Paulo – 2015/17213-2. Dr. Bensenor, Dr. Barreto, Dr Giatti, Dr. Duncan, Dr. Alvim, Dr. Griep, Dr. Fonseca, Dr. Mill, Dr Molina, Dr. Schmidt, Dr. Santos, Dr. Goulart, and Dr Lotufo are recipients of a scholarship of National Research Council (CNPq).