Table 1.

Overview of sex- and gender-differences that could be responsible of increased mortality rate in men with Covid-19.

Activity of the immune system	▘ Female patients seem to have an intense and prolonged innate, humoral, and cell-mediated immune response, leading to a faster and higher recognition of viral components ▘ Preclinical studies showed that females might recover to a greater extent and are better protected from death during infections
Role of sex hormones	▘ Testosterone shows suppressive effect on the immune function, while estrogen may have both suppressive and not suppressive effects depending on their levels ▘ In men androgens deficiency is associated with increased levels of inflammatory cytokines and increased CD4+/CD8+ T-cell ratio ▘ Estrogens are able to induce an upregulation in the expression of ACE2 ▘ Exogenous estrogen increases the clotting risk in women and in biological males undergoing gender-affirming hormonal therapy ▘ Sex hormones could also affect the response to antiviral treatments or vaccines
Prevalence of cardiovascular diseases	▘ Women seem to have a higher risk and incidence of symptomatic supraventricular tachycardia and long QT syndrome compared with men ▘ Men show higher risk of atrial fibrillation and sudden cardiac death and they are more affected by atherosclerotic cardiovascular disease compared with women
Coagulation pattern	▘ Men have a 3.6-fold higher risk of recurrent VTE than women ▘ Women show higher risk of VTE during fertile years
Smoking and drinking habits	▘ Smoking habit is higher in men than women ▘ Drinking habit is higher in men than women