Differences in COVID-19 mortality in males and females: Is estrogen hormone attributing to sex differences?

Abstract

Globally, the case fatality ratio is more in males versus females. Some studies have suggested estrogen hormone decreases susceptibility to SARS CoV-2. We have analyzed the observed sex differences in COVID-19 behavior in males and females and the clinical profiles of females of different age groups of COVID-19 patients and discussed their symptoms, laboratory evaluations, and associated comorbidities. The patients were tested for COVID-19 through real-time RT-PCR (Reverse Transcription Polymerase Chain Reaction) assay. The data obtained were studied for the epidemiological, clinical, and laboratory characteristics from their medical records. The mortality rate in females was 12.33% (36/292) whereas mortality in males was 19.63% (84/428). In between group analysis, 8.7% (14/161) of females died in the <40 years age group versus 16.8% (22/131) in more than 40 years age group whereas in males, the mortality was 13.7% (21/153) in <40 years versus 22.9%(63/275). The mortality rate in women older than 40 years was greater than mortality in younger females emphasizing the protection provided by estrogen hormone in them. The proportion of patients who expired due to COVID-19 significantly differs by age cutoff of 40 years, X2 (1, n = 428). The difference is statistically significant at P < 0.05. Males more than 40 years are more likely to expire. Sex-related differences in coronavirus pandemic have been found pointing toward the protective role of estrogen hormone and other differences in immunological behavior in males and females. Downregulation of ACE2 expression, thereby reducing viral entry, might also be contributory to decreasing mortality in females.