Shedding light on sex differences in COVID-19 mortality

Institute news

Many people are aware that male patients with COVID-19 are more symptomatic and exhibit increased disease severity, higher complication rates, and ultimately higher mortality.

A paper by Baker Institute researchers published this week in the journal, Cardiovascular Research, provides some potential explanations for why this might be so, and questions whether sex-specific therapies in COVID-19 may be needed.

The researchers describe how the immune response, specialised in recognising and fighting foreign invaders such as viruses, is different between males and females. These differences are likely due to both genetic variation and contrasting hormone levels.

Highlighting this variation in male and female immune responses is the fact that an overshooting immune response appears to be common in male COVID-19 patients. In other words, the immune response over-reacts to the viral infection, causing excessive damage and leading to poorer outcomes.

One of the study authors, Dr Jonathan Noonan, says this suggests that fundamental biological differences between males and females, particularly in relation to immune responses, may hold the answer to the bias seen towards male mortality in COVID-19.

Many COVID-19 patients also suffer from cardiovascular complications. Dr Noonan says as the immune response plays a key role in cardiovascular disease (CVD), they describe how COVID-19 and CVD may interact to promote worse outcomes in those with, or at risk, of CVD.

“The significant bias towards male deaths in COVID-19 and the clear interaction with CVD highlights the importance of considering sex-specific therapies in COVID-19,” the researchers say. “It also highlights the general point that the pathology and therapy of many diseases might require specific sex-specific approaches. The observed sex differences in COVID-19 also provide a unique opportunity to better understand and ultimately treat SARS-CoV-2 infections.”