Post-COVID mortality risk may be caused by effects of high inflammation during illness

A new study provides insight on why people who recover from severe COVID-19 still have a higher risk of death

By Jill Pease

A UF study sheds new light on the reason people who recover from a bout of severe COVID-19 are still at increased risk for death in the year after their recovery. The culprit may be high levels of inflammation during the initial illness.

The UF team previously reported that patients who recovered from severe COVID-19 have more than twice the mortality risk within the year following their illness than people who have not contracted the virus. The new findings, published in the journal Frontiers in Medicine, are the first to use biomarkers to help explain the increased risk.

“This study helps to clarify why people who are hospitalized with COVID-19 end up being at high risk for death after they recover. The findings also take us to a new level of understanding of not just the mechanism for illness, but also a potential treatment that may prevent deaths among these patients,” said Arch G. Mainous III, Ph.D., the study’s lead investigator and a professor in PHHP’s department of health services research, management and policy.

UF researchers analyzed electronic health records for more than 1,200 patients hospitalized for COVID-19 between Jan. 1, 2020 and Dec. 31, 2021 at one health system, and tracked the patients for up to one year following discharge. After adjusting for factors including age, race, gender and select existing medical conditions, the scientists found that patients who had higher levels of inflammation during illness — as measured by a biomarker known as C-reactive protein — were 60% more likely to die within a year after infection than those who had lower levels of inflammation.

Previous studies have linked hyperinflammation and an overreaction of the immune system known as a cytokine storm to severe cases of COVID-19 and multi-organ damage. The UF study suggests the health effects from such a severe inflammatory response persist well after patients recover.

The UF study also points to a potential treatment that may prevent deaths following COVID-19 recovery. Health records revealed those patients who were prescribed an oral steroid at the time of hospital discharge had a lower risk of post-illness mortality than patients with severe COVID-19 who were not prescribed the anti-inflammatory drugs.

Taken together, the findings from the UF team on long-term mortality risks among patients who have had severe COVID-19 suggest a reconceptualization of the disease, Mainous said.

“This research allows us to see COVID-19 in a new way,” said Mainous, also vice chair for research in the UF College of Medicine’s department of community health and family medicine. “Many have viewed COVID-19 as being similar to other infectious diseases; if you get rid of the virus or bacteria, the person is cured. Because of the lingering health risks, we may need to shift our thinking to approach COVID-19 as both an acute and chronic condition.”