Thyroid Hormones within the Normal Range and Cardiac Function in the General Population: The EPIPorto Study

Autores da FMUP

• João Sérgio De Lima Soares Neves

  Autor

• Ricardo Manuel Alves Monteiro Fontes De Carvalho

  Autor

• Marta Borges Canha

  Autor

• João Tiago De Sousa Pinto Guimarães

  Autor

• Davide Maurício Costa Carvalho

  Autor

• Joaquim Adelino Correia Ferreira Leite Moreira

  Autor

• Ana Azevedo Cardoso Oliveira

  Autor

Participantes de fora da FMUP

• Leite, AR
• Martins, S
• Oliveira, A

Unidades de investigação

• Biomedicina

• Ciências da Saúde Pública e Forenses, e Educação Médica

• Cirurgia e Fisiologia

• Medicina

• RISE-Health

  

  Investigador

  Fernando Carlos De Landér Schmitt

Abstract

Background: Hypothyroidism and hyperthyroidism are associated with marked changes in cardiac structure and function. However, the association of thyroid function within the normal range with cardiac structure and function in the general population remains uncertain. Methods: Eight hundred thirty-five subjects aged >= 45 years from the EPIPorto cohort (evaluation between 2006 and 2008) were cross-sectionally analyzed. We excluded participants with TSH, free T4 (FT4), or free T3 (FT3) outside of the reference range or with self-reported cardiovascular or thyroid disease. Cardiac structure and function were evaluated by echocardiography. We used linear regression models unadjusted and adjusted for sex and age (model 1), and sex, age, BMI, diabetes, hypertension, and smoking (model 2). Nonlinear associations were assessed using restricted cubic splines. Results: The mean age was 61.5 years (SD 10.5); 61.1% of the patients were women. In the adjusted model 2, heart rate was positively associated with FT3; diastolic blood pressure was positively associated with TSH; LV end-diastolic and end-systolic volumes were inversely associated with TSH, and ejection fraction was nonlinearly associated with FT3, with higher ejection fractions near the limits of the reference range. Left ventricle (LV) posterior wall thickness was nonlinearly associated with FT4 in the adjusted model 1, with a greater thickness near the limits of the reference range. Regarding diastolic function, no significant associations were observed in adjusted models. Conclusions: Thyroid function within the reference range was associated with heart rate, blood pressure, cardiac structure, and function. Increasing thyroid function (lower TSH, higher FT4, or higher FT3) was associated with a higher heart rate, a lower diastolic blood pressure, and larger LV volumes. LV wall thickness and ejection fraction had a U-shaped association with thyroid hormones.

Copyright © 2020 by S. Karger AG, Basel.

Keywords

• Thyroid hormones; Cardiac function; Cardiac structure; Thyroid stimulating hormone; Free T4; Free T3