Men who were hospitalized for COVID-19 in New York City during the early days of the pandemic were both younger and healthier on average than their female counterparts, according to a new study by researchers at the Icahn School of Medicine at Mount Sinai. The study, posted to the preprint server medRxiv, analyzed the electronic health records of 3,086 racially diverse COVID-19 patients who were admitted to five hospitals within the Mount Sinai Health System on or before April 13, 2020, and followed through June 2, 2020.
“Just being male seemed to be a risk factor in and of itself,” says the study’s first author, Tomi Jun, MD, a hematology and medical oncology Fellow at The Tisch Cancer Institute of the Mount Sinai Health System. Members of Mount Sinai’s Department of Genetics and Genomic Sciences, and Scientific Computing and Data Science, also contributed to the study.
Of those requiring hospitalization, 59.1 percent were male with a median age of 64, vs. 74 years of age for women. While the men were more likely to have a history of smoking, the women were more likely to have pre-existing comorbidities such as hypertension, diabetes, chronic obstructive pulmonary disease and asthma, and obesity. The mortality rate for men and women was equal.
Tomi Jun, MD
“This was during the early days when there was a surge of cases in New York and we did not have effective treatments,” says Dr. Jun. “Looking at the data, there were a disproportionate number of men being hospitalized. And these men seemed to be healthy enough to do well with COVID-19, because we know that older age and having more comorbidities are associated with worse outcomes. When you take all those things into account, being male seemed to increase your risk.”
Kuan-lin Huang, PhD, Assistant Professor of Genetics and Genomic Sciences, and the study’s senior author, says, “We know there are a lot of hormonal and immunological differences between men and women. There are certain genes on the X chromosome that are involved in the immune system and women have two X chromosomes. Women go through pregnancy, which can have strong effects on the immune system. And we know that women are at higher risk of developing an autoimmune disease. Likely, it’s a complex set of these factors that contributed to the results. Specifically what is it? I don’t think anyone knows for sure. But that is what we were trying to get closer to with this and subsequent studies.” Understanding the underpinning of why this is happening at the molecular level, he adds, will provide insights into potential treatments.
Kuan-lin Huang, PhD
The researchers found interesting results when they examined data about the patients’ blood. “COVID-19 is very inflammatory and all of the hospitalized patients had very high markers of inflammation,” says Dr. Jun. “But we observed that women tended to have lower markers of inflammation than men. We conducted exploratory analyses to look at how predictive these markers were for death and found that in some cases higher markers for inflammation were associated with higher risk in women than men. So, although women, in general, had less inflammation than men when they entered the hospital, having higher indicators of inflammation seemed to confer a greater risk for them.”
Dr. Huang says the current study is a jumping-off point for future investigations that was made possible by Mount Sinai’s policy of allowing its data and clinical scientists to access the electronic health records.
“If our hospitals hadn’t taken care of all these patients and we didn’t know their histories we wouldn’t be able to do this research,” he says. “We really hope this will lead to more precise patient management. We should have different considerations for men and women when we think about whether that may add on to the risk of a COVID-19 patient.”