A new study looking at data from nearly 100,000 subjects in Houston, Texas, has affirmed men seem much more vulnerable to COVID-19 than women. The study found men, independent of age, are more likely to contract the virus, suffer from severe complications, and die from the disease compared to women.

One of several compelling epidemiological observations arising in 2020, as the novel coronavirus SARS-CoV-2 rapidly spread across the world, was the tendency for men to be hit harder by COVID-19 than women. Early, small studies out of China seemed to suggest men were suffering from more severe cases of COVID-19.

This new research, led by Farhaan Vahidy from the Houston Methodist Research Institute, set out to investigate the association between biological sex and COVID-19 in a large US metropolitan city. Data from nearly 100,000 subjects undergoing SARS-CoV-2 testing were analyzed.

The results revealed men were more likely to test positive for the virus, they were more likely to be admitted into intensive care, and ultimately more likely to die from the disease. According to the researchers, these sex differences were still present even after adjusting for, “age, race, ethnicity, marital status, insurance type, median income, BMI, smoking and 17 comorbidities.”

Early on in the pandemic the observation that males were more susceptible to COVID-19 was hypothesized to be due to gender differences in social behaviors. A CDC report published in July 2020 suggested men are more likely to downplay the risk of COVID-19, disregard preventative advice such as social distancing and mask-wearing, and engage in high-risk activities such as attending public gatherings.

Although the CDC report did not disregard the possible biological sex differences that could influence COVID-19 severity, the study did hypothesize psychosocial and behavioral factors play a significant role in explaining epidiomelogical differences between men and women. However, Vahidy and colleagues note in their new study that there has been enough observation of COVID-19 sex differences across a spread of cultural and geographical areas to suggest the differences may not primarily be social or behavioral.

“While gender-related behaviors such as smoking, drinking, the propensity to seek hospital care and presence of comorbidities could affect the outcome of COVID-19, the increased risk of death seen in males across several different cultures in the world point to biological risk determinants,” the researchers write.

It is not unusual for diseases to affect men and women differently. Parkinson’s disease, for example, occurs in men much more frequently than women, while Alzheimer’s disease is the other way around, striking women at much higher rates than men. A growing body of research is working to unpack the biological sex differences in disease risk.

In the case of COVID-19, scientists are investigating several possible reasons for why the disease could hit men harder than women. A robust article in Nature last year presented a strong case for sex-based immune differences being key to variances in disease severity, while a more recent Australian study suggested men have more ACE2 receptors on lower lung cells which could account for their greater vulnerability to COVID-19.

“Sex disparities in COVID-19 vulnerability are present, and emphasize the importance of examining sex-disaggregated data to improve our understanding of the biological processes involved to potentially tailor treatment and risk stratify patients,” conclude Vahidy and colleagues in the new study.

The new research was published in the journal PLOS ONE.

Source: Houston Methodist