Prevalence of thyroid disorders among older people: results from the São Paulo Ageing & Health Study

Abstract

This study aimed to estimate prevalence of thyroid disorders in the São Paulo Ageing & Health Study, an epidemiological study addressing several health-adverse outcomes among elderly people living in a poor area of São Paulo, Brazil. All participants answered a questionnaire and had a blood sample collected to assess levels of tireotropic hormone and free-thyroxine. Among 1,373 people (60.8% women), prevalence rates (95% confidence interval) for thyroid dysfunction (%) were: overt hyperthyroidism, 0.7% (0.2-1.1)[women: 0.8% (0.2-1.5); men: 0.4% (0.01-0.9)]; overt hypothyroidism, 5.7% (4.5-6.9) [women: 5.9% (4.3-7.5); men: 5.4% (3.5-7.3)]; subclinical hyperthyroidism, 2.4% (1.6-3.2) [women: 2.8% (1.6-3.9); men: 1.9% (0.7-3.0)]; and subclinical hypothyroidism, 6.5% (5.2-7.8) [women: 6.7% (5.0-8.4); men: 6.1% (4.1-8.2)]. There was no difference in prevalence rates according to gender, but almost 40% of women were diagnosed and under treatment compared to 9% of men. The burden of thyroid disorders in this sample is high and most participants were not aware of them.

O objetivo da pesquisa foi avaliar a prevalência de doenças da tireóide no São Paulo Ageing & Health Study, estudo epidemiológico focado em desfechos de saúde adversos em amostra de idosos moradores de São Paulo, Brasil. Todos os participantes responderam a questionário e colheram sangue para dosagem de hormônio tireotrópico e tiroxina-livre. Entre os 1.373 participantes (60,8% mulheres), a prevalência (intervalo de 95% de confiança) de hipertireoidismo clínico foi de 0,7% (0.2-1,1) [mulheres: 0,8% (0,2-1,5); homens: 0,4% (0,01-0,9)]; hipotireoidismo clínico, 5,7% (4,5-6,9) [mulheres: 5,9% (4,3-7,5); homens: 5,4% (3,5-7,3)]; hipertireoidismo subclínico, 2,4% (1,6-3,2) [mulheres: 2,8% (1,6-3,9); homens: 1,9% (0,7-3,0)]; e hipotireoidismo subclínico, 6,5% (5,2-7,8) [mulheres: 6,7% (5,0-8,4); homens: 6,1% (4,1-8,2)]. Não houve diferença na prevalência de doenças da tireóide por sexo. Quarenta por cento das mulheres tinham diagnóstico e estavam tratando, comparadas a 9% dos homens. A prevalência de disfunção tireoidiana foi elevada e a maioria dos participantes desconhecia o diagnóstico.