TOPLINE:

Among working-age adults in the US, COVID was associated with higher risks for acute kidney injury (AKI), chronic kidney disease (CKD), or end-stage renal disease (ESRD) than influenza. The risk for AKI was greatest soon after infection, whereas the elevated risk for CKD persisted over a longer follow-up period.

METHODOLOGY:

• Researchers conducted a retrospective cohort study using real-world data for over 3 million US adults to determine whether COVID, compared with both influenza and no infection, was associated with elevated risk for subsequent kidney diseases.
• They analyzed the data of 939,241 patients with COVID (mean age, 41.3 years; 47.3% men), 199,071 patients with influenza infection but no history of COVID (mean age, 39.7 years; 43.1% men), and 1,878,482 individuals with no infection with either virus (mean age, 41.3 years; 47.3% men).
• Cohorts included patients aged 18-64 years identified by standard diagnostic codes who had continuous insurance enrollment for at least 1 year before and 90 days after the date of their first COVID or influenza diagnosis; those with a history of kidney disease were excluded.
• Patients were matched based on age, sex, geographical region, and timing of infection.
• The outcomes were new onset of kidney diseases and subgroups — including AKI, CKD, and ESRD — identified using standard diagnostic codes; the median follow-up duration was 324 days.

TAKEAWAY:

• Compared with no infection, COVID was associated with higher risks for new onset of any kidney disease (adjusted hazard ratio [aHR], 1.93; 95% CI, 1.87-2.00), CKD (aHR, 1.38; 95% CI, 1.32-1.45), AKI (aHR, 2.74; 95% CI, 2.61-2.87), and ESRD (aHR, 3.22; 95% CI, 2.67-3.88).
• Influenza infection was associated with modest increases in the risks for any kidney disease (aHR, 1.10; 95% CI, 1.01-1.19) and AKI (aHR, 1.24; 95% CI, 1.11-1.38) compared with no infection.
• In direct comparisons between the COVID and influenza groups, COVID was associated with higher risks for AKI (aHR 2.28; 95% CI, 2.00-2.60), CKD (aHR, 1.39; 95% CI, 1.21-1.60), and ESRD (aHR 4.67; 95% CI, 2.85-7.66).
• The effect of COVID vs no infection on AKI was strongest in the short term and declined over time, whereas the increased risk for CKD remained persistently elevated throughout the follow-up period.

IN PRACTICE:

“These findings indicate that COVID-19 has a stronger and more sustained impact on kidney diseases than influenza and highlight the need for greater attention to kidney outcomes following COVID infection,” the authors wrote.

SOURCE:

This study was led by Yue Zhang, Penn State College of Medicine in Hershey, Pennsylvania. It was published online in Communications Medicine.

LIMITATIONS:

The findings may not be generalizable to older adults, children, or uninsured patients, who often experience more severe COVID and influenza. The claims data lacked details of inpatient discharge and information on deaths. Disenrollment occurred unevenly across groups, with patients who had influenza or COVID more likely to disenroll from the database during the follow-up period.

DISCLOSURES:

This study was supported by the Artificial Intelligence and Biomedical Informatics Pilot Funding program at Penn State College of Medicine. The authors disclosed having no conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.