Sex Differences in the Outcome of Patients with Confirmed SARS-CoV-2 Infection

Background: More than half of deaths due to coronavirus disease 2019 (COVID-19) occur in men. The reasons behind this fact have been poorly studied. We aimed to test the hypothesis that risk factors aggregation is not the only explanation of the high case fatality rate (CFR) observed in men with COVID-19. Methods: We analyzed the May 25th 2020 Mexican Ministry of Health's official database on all people tested for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection by real-time reverse transcriptase–polymerase chain reaction (rtRT-PCR) of nasopharyngeal swabs. An electronic database was arranged for the present analysis with collected risk factors and epidemiological information. Results: We studied 65,856 patients with confirmed COVID-19. Compared with men, women had a higher prevalence of hypertension, obesity, asthma, chronic obstructive pulmonary disease (COPD), and immunosuppression; whereas men had a higher frequency of smoking, indigeneity and chronic kidney disease (CKD). There were 7179 (CFR: 10.9%) deaths in total, 4870 (67.8%) occurring in men, and 2309 (32.2%) in women (CFR 13% vs. 8.2%, respectively; HR: 1.60, 95% CI: 1.52–1.68; P<0.001). To account for risk factors aggregation putatively explaining the high CFR in men, we performed a separate analysis by risk factor group, age categories and sex. In the groups with hypertension, diabetes, obesity, and smoking, CFR was higher at almost every age category in men. In the groups with COPD, cardiovascular disease, CKD, asthma, and immunosuppression, CFR was higher in men or there were no significant differences compared with women. Moreover, CFR was higher in men than in women, even in subgroups of individuals with different number of risk factors. Interpretation: We found that risk factors aggregation is not the only explanation for the high CFR in men with rtRT-PCR-confirmed COVID-19. Funding Statement: This study did not receive sponsorship. Declaration of Interests: The authors declare that there are no competing conflicts of interest.