Hypothyroidism does not lead to worse prognosis in COVID-19: findings from the Brazilian COVID-19 registry
Authors: Pereira Daniella Nunes , Gontijo Silveira Leticia Ferreira , Moreira Guimarães Milena Maria , Polanczyk Carísi Anne , Sousa Nunes Aline Gabrielle , de Moura Costa André Soares , Farace Barbara Lopes , Rodrigues Cimini Christiane Corrêa , de Carvalho Cíntia Alcantara , Ponce Daniela , Roesch Eliane Würdig , Fernandes Manenti Euler Roberto , Lucas Fernanda Barbosa , Rodrigues Fernanda d’Athayde , Anschau Fernando , Aranha Fernando Graça , Bartolazzi Frederico , Vietta Giovanna Grunewald , Nascimento Guilherme Fagundes , Duani Helena , Vianna Heloisa Reniers , Guimarães Henrique Cerqueira , Martins Costa Jamille Hemétrio Salles , Lyra Batista Joanna d’Arc , de Alvarenga Joice Coutinho , Chatkin José Miguel , de Morais Júlia Drumond Parreiras , Machado-Rugolo Juliana , Ruschel Karen Brasil , Pinheiro Lílian Santos , Monteiro Menezes Luanna Silva , Ferreira Couto Luciana Siuves , Kopittke Luciane , de Castro Luís César , Nasi Luiz Antônio , de Souza Cabral Máderson Alvares , Floriani Maiara Anschau , Souza Maíra Dias , Carneiro Marcelo , Camargos Bicalho Maria Aparecida , de Godoy Mariana Frizzo , Alves Nogueira Matheus Carvalho , Guimarães Júnior Milton Henriques , Severino Sampaio Natália da Cunha , de Oliveira Neimy Ramos , Assaf Pedro Ledic , Finger Renan Goulart , Campos Roberta Xavier , Menezes Rochele Mosmann , Francisco Saionara Cristina , Alvarenga Samuel Penchel , Mereilles Guimarães Silvana Mangeon , Araújo Silvia Ferreira , Oliveira Talita Fischer , Oliveira Diniz Thulio Henrique , Ramires Yuri Carlotto , de Almeida Cenci Evelin Paola , de Oliveira Thainara Conceição , Schwarzbold Alexandre Vargas , Ziegelmann Patricia Klarmann , Pozza Roberta , Pires Magda Carvalho , Marcolino Milena Soriano 
Published: November 2021

AbstractBackgroundIt is not clear whether previous thyroid diseases influence the course and outcomes of COVID-19. The study aims to compare clinical characteristics and outcomes of COVID-19 patients with and without hypothyroidism.MethodsThe study is a part of a multicentric cohort of patients with confirmed COVID-19 diagnosis, including data collected from 37 hospitals. Matching for age, sex, number of comorbidities and hospital was performed to select the patients without hypothyroidism for the paired analysis.ResultsFrom 7,762 COVID-19 patients, 526 had previously diagnosed hypothyroidism (50%) and 526 were selected as matched controls. The median age was 70 (interquartile range 59.0-80.0) years-old and 68.3% were females. The prevalence of underlying comorbidities were similar between groups, except for coronary and chronic kidney diseases, that had a higher prevalence in the hypothyroidism group (9.7% vs. 5.7%, p=0.015 and 9.9% vs. 4.8%, p=0.001, respectively). At hospital presentation, patients with hypothyroidism had a lower frequency of respiratory rate > 24 breaths per minute (36.1% vs 42.0%; p=0.050) and need of mechanical ventilation (4.0% vs 7.4%; p=0.016). D-dimer levels were slightly lower in hypothyroid patients (2.3 times higher than the reference value vs 2.9 times higher; p=0.037). In-hospital management was similar between groups, but hospital length-of-stay (8 vs 9 days; p=0.029) and mechanical ventilation requirement (25.4% vs. 33.1%; p=0.006) were lower for patients with hypothyroidism. There was a trend of lower in-hospital mortality in patients with hypothyroidism (22.1% vs. 27.0%; p=0.062).ConclusionIn this large Brazilian COVID-19 Registry, patients with hypothyroidism had a lower requirement of mechanical ventilation, and showed a trend of lower in-hospital mortality. Therefore, hypothyroidism does not seem to be associated with a worse prognosis, and should not be considered among the comorbidities that indicate a risk factor for COVID-19 severity.