The Age Pattern of the Male- to- Female Ratio in Mortality from COVID-19 Mirrors that of Cardiovascular Disease but not Cancer in the General Population

Background: Males are at a higher risk of dying from COVID-19. Older age and cardiovascular disease are also associated with COVID-19 mortality. We compared the male-to-female (sex) ratios in mortality by age for COVID-19 with cardiovascular mortality and cancer mortality in the general population. Methods: We obtained data from official government sources in the US and five European countries: Italy, Spain, France, Germany, and the Netherlands. We analyzed COVID-19 deaths by sex and age in these countries and similarly analyzed their deaths from cardiovascular disease (coronary heart disease or stroke) and cancer, the two leading age-related causes of death in middle-to-high income countries. Findings: In both the US and European countries, the sex ratio of deaths from COVID-19 exceeded one throughout adult life. The sex ratio increased up to a peak in midlife, and then declined markedly in later life. This pattern was also observed for the sex ratio of deaths from cardiovascular disease, but not cancer, in the general populations of the US and European countries. Interpretation: The sex ratios of deaths from COVID-19 and from cardiovascular disease exhibit similar patterns across the adult life course. The underlying mechanisms are poorly understood, but could stem partially from sex-related biological differences that underlie the similar pattern for cardiovascular disease. These include, we propose, comparatively longer telomeres in females, ovarian hormones, and X chromosome mosaicism.