key: cord-0922831-1k7bi6ng
authors: Moiseev, Sergey; Brovko, Michail; Tao, Ekaterina; Bulanov, Nikolay; Fomin, Larisa Akulkina Victor
title: Sex differences in mortality in the intensive care unit patients with severe COVID-19
date: 2020-09-28
journal: J Infect
DOI: 10.1016/j.jinf.2020.09.031
sha: b5ceb7dff94731a8c0fbd6be7a43fd9307afe60a
doc_id: 922831
cord_uid: 1k7bi6ng

nan

The available evidence suggests that mortality from coronavirus disease 2019 in males is higher than in females. 1 In a recent cross-sectional study, de Lusignan et al. evaluated the absolute excess risk (AER) of mortality and excess mortality rate (EMR) in the UK from a COVID-19 sentinel surveillance network in people aged 45 years and above. 2 The AER in mortality was calculated by comparing mortality for weeks 2 to 20 this year with mortality data from the Office for National Statistics (ONS) from 2018 for the same weeks. The absolute excess mortality was approximately 2 deaths per 100 person years in the first wave of COVID-19, whereas the EMR for male gender, compared with female, was 1.4 (95% confidence interval

[CI] 1.35-1.44, p<0.00) .

We investigated the sex-related differences in the occurrence of comorbidities and mortality rates in a nationwide study in 1522 consecutive patients with severe SARS-CoV-2 pneumonia who were admitted to intensive care unit (ICU) for respiratory support. Medical records of patients were submitted by the COVID-19 hospitals located in 70 regions across Russia to the Federal Center at the Sechenov University In the total cohort, the requirement for mechanical ventilation and mortality rates were similar in males and females (Table 1) . However, female patients were older and had a higher occurrence of various chronic illnesses, that is, arterial hypertension, obesity and type 2 diabetes, that impair prognosis in patients with COVID-19. 4, 5 Coronary artery disease (CAD) and chronic obstructive pulmonary disease (COPD) were more frequent in males than in females, although their occurrence was lower compared to that of the other significant comorbidities. The mortality rates increased with age both in males and females. In patients aged 50 years or younger, the mortality rates were similar in males and females (odds ratio [OR] p=0.021), whereas the requirement for mechanical ventilation did not differ between sexes. In all age groups, the occurrence of arterial hypertension, type 2 diabetes and obesity was higher in females than in males, although these differences reached statistical significance only in a proportion of cases (Table 1) . On the contrary, CAD occurred significantly more frequently in males aged 51-60 and 61-70 years than in females of similar age, whereas the frequency of COPD was increased in males aged 61-70 and ≥70 years.

In summary, the mortality rate in the ICU patients with severe SARS-CoV-2 pneumonia was higher in males aged >50 years than in females of similar age. Our findings are in line with de Lusignan et al. data, who reported a higher EMR in males during the COVID-19 pandemic in the English population. The differences between mortality rates in males and females cannot be explained by comorbidities, given the divergent trends in the occurrence of chronic illnesses that may worsen survival in COVID-19 patients. Al-Lami et al. suggested that low levels of testosterone, as can occur in normally aging men, may account for more severe lung damage since testosterone deficiency has been linked with autoimmune disease and increases in inflammatory markers. 6 Moreover, anti-inflammatory effects of estrogens may protect females from progression of SARS-CoV-2 induced lung disease. Our data indirectly support that sex steroid hormones underlie sex-related differences in COVID-19 mortality.

Sergey Moiseev, Michail Brovko, Ekaterina Tao, Nikolay Bulanov, Larisa Akulkina 

Sex differences in severity and mortality from COVID-19: are males more vulnerable?

Disparities in the excess risk of mortality in the first wave of COVID-19: Cross sectional study of the English sentinel network

Coronavirus disease 2019 (COVID-19): a systematic review of imaging findings in 919 patients

Coronavirus infections and type 2 diabetes -shared pathways with therapeutic implications

COVID-19 and obesity: dangerous liaisons

Sex hormones and novel corona virus infectious disease (COVID-19)

Whitney U test for continuous variables; Me(IQR) = median

ECMO = extracorporeal membrane oxygenation

CAD = coronary artery disease (a history of myocardial infarction or interventions on the coronary arteries)

AF = atrial fibrillation; j Obesity was defined as body mass index ≥30 kg/m 2

COPD = chronic obstructive pulmonary disease