Clinical presentation and prognosis of COVID-19 in older adults with hypothyroidism: data from the GeroCovid observational study

Background The prevalence of hypothyroidism among older patients hospitalized for COVID-19 and its association with mortality is unclear. This study aims to investigate the prevalence of hypothyroidism in older COVID-19 inpatients and verify if this comorbidity is associated with a specifc pattern of onset symptoms and a worse prognosis. Methods COVID-19 inpatients aged≥60 years, participating in the GeroCovid acute wards cohort, were included. The history of hypothyroidism was derived from medical records and the use of thyroid hormones. Sociodemographic data, comorbidities, symptoms/signs at the disease onset and infammatory markers at ward admission were compared between people with vs without history of hypothyroidism. The association between hypothyroidism and in-hospital mortality was tested through Cox regression. Results Of the 1245 patients included, 8.5% had a history of hypothyroidism. These patients were more likely to present arterial hypertension and obesity compared with those without an history of hypothyroidism. Concerning COVID-19 clinical presentation, patients with hypothyroidism had less frequently low oxygen saturation and anorexia but reported muscle pain and loss of smell more commonly than those without hypothyroidism. Among the infammatory markers, patients with hypothyroidism had higher lymphocytes values. At Cox regression, hypothyroidism was associated with reduced in-hospital mortality only in the univariable model (HR=0.66, 95% CI 0.45–0.96, p=0.03); conversely, no signifcant result were observed after adjusting for potential confounders (HR=0.69, 95% CI 0.47–1.03, p=0.07). Conclusions Hypothyroidism does not seem to substantially infuence the prognosis of COVID-19 in older people, although it may be associated with peculiar clinical and biochemical features at the disease onset.