Background: Pneumonia is both the most common type of lower respiratory tract infection and a major cause of morbidity and mortality worldwide. The COVID-19 pandemic caused by the SARS-CoV-2 raised an extremely serious concern, because its most frequent clinical presentation was pneumonia. Features such as sex play an active role in the incidence and outcomes of pneumonia. This study aimed to evaluate differences between sexes concerning COVID-19-related pneumonia.
Methods: This was a retrospective, multicenter study that enrolled 340 consecutive adult patients admitted to hospital for COVID-19-related pneumonia. Of these patients, 219 were males (64.4%) and 121, females (35.6%). Primary endpoints were differences between both sexes as per clinical features, laboratory and radiologic results, and in-hospital and 30-day mortality. Secondary outcomes included differences between both sexes and factors associated with mortality.
Results: Males admitted to the COVID-19 Unit were older than females (74.5±15.7 vs. 64.5±11.9). Cardiovascular disorders were more frequent in males (19.17% vs. 13.25%), whereas obesity was more common in females (54.5% vs. 37.45%). In-hospital and 30-day mortality were higher in males than in females (23.3% vs. 15.7%; 24.6% vs. 19.8%, respectively). No differences were observed in hospital stay; however, males had a longer ICU stay when compared with females (11.04±5.4 vs. 7.05±3.4). Variables associated with a higher mortality rate included older age, a lower number of lymphocytes upon admission and higher levels of ferritin and troponin upon admission.
Conclusions: Males had significantly higher mortality and longer ICU stay than females. More comorbidities in males than in females could explain the difference in mortality rates. The protective role of genetic factors can partially explain the better outcomes observed in female patients with COVID-19.