COVID-19 Survivors Face Significantly Higher Risk of Kidney Disease, New Study Reveals

A major new study from Penn State College of Medicine found that people who had COVID-19 are at substantially higher risk for developing kidney disease compared to those who had the flu. Researchers analyzed data from over 3 million working-age adults in the United States and discovered that COVID-19 survivors have a 2.3-times higher risk of acute kidney injury, a 1.4-times higher risk of chronic kidney disease (CKD), and are 4.7 times more likely to experience kidney failure.

This finding matters because kidney disease often develops silently. Approximately 90% of people with chronic kidney disease don't realize they have it because early stages typically cause no symptoms. The discovery that COVID-19 significantly increases kidney disease risk could help doctors identify patients who need closer monitoring and earlier intervention.

Why Does COVID-19 Specifically Target the Kidneys?

The virus that causes COVID-19, called SARS-CoV-2, appears to have a particular ability to damage kidney cells. Researchers explain that kidney cells express high levels of the primary protein receptors that SARS-CoV-2 uses to enter and infect cells. Additionally, kidney cells produce specialized enzymes that help viruses enter cells, making them especially vulnerable to this particular virus.

Importantly, while both COVID-19 and influenza can affect kidney health, the effects differ significantly. The flu's impact on kidneys is mild and temporary, whereas COVID-19 causes more sustained damage that can lead to both short-term acute kidney injury and longer-term chronic kidney disease.

How Was This Research Conducted?

The Penn State team, led by assistant professor Djibril Ba, developed machine learning models to predict kidney disease risk by analyzing health insurance claims data from 2020 and 2021. Researchers divided over 3 million participants into three groups: those with a history of COVID-19 infection, those with a history of influenza but not COVID-19, and those with neither infection. People already diagnosed with kidney disease were excluded from the study.

Participants were followed for between 180 and 540 days, with an average follow-up period of 324 days, to track the emergence of new acute kidney injury, chronic kidney disease, and end-stage renal disease requiring dialysis or transplant. The researchers matched participants based on age, sex, geographical region, and timing of infection to account for different virus variants.

What Should COVID-19 Survivors Do About Their Kidney Health?

The research team recommends that individuals with a history of COVID-19 infection receive more frequent and prolonged monitoring of their kidney function. "Individuals with COVID-19 infection may need more frequent and more prolonged monitoring of their kidney function to enable earlier detection and possible preventative interventions," said Nasr Ghahramani, J. Lloyd Huck Chair in Medicine and professor of medicine and public health sciences at Penn State College of Medicine.

This recommendation is particularly important for people who already have risk factors for kidney disease, such as diabetes or high blood pressure. These individuals face compounded risk and would benefit most from proactive kidney monitoring.

Steps to Protect Your Kidney Health After COVID-19

• Schedule Regular Kidney Function Tests: Ask your primary care doctor to monitor your kidney function through blood tests (measuring creatinine levels) and urine tests. This is especially important if you had moderate to severe COVID-19 or have underlying conditions like diabetes or hypertension.
• Monitor Blood Pressure and Blood Sugar: Keep your blood pressure and blood sugar levels in target ranges, as these conditions compound kidney disease risk. Work with your doctor to manage these conditions aggressively.
• Maintain Healthy Lifestyle Habits: Stay hydrated, limit sodium intake, avoid excessive protein consumption, and maintain a healthy weight. These steps support overall kidney function and reduce additional strain on the organs.
• Report Symptoms Promptly: Watch for signs of kidney problems such as swelling in the legs or ankles, fatigue, shortness of breath, or changes in urination patterns, and report these to your doctor immediately.

How Does This Finding Change Kidney Disease Prevention?

This research represents the first large-scale study to investigate the relationship between COVID-19 and kidney disease across a broad population and to compare it directly with another common viral infection. The findings align with earlier case reports and smaller observational studies suggesting COVID-19 increases kidney disease risk, but this analysis provides much stronger evidence from a much larger group of people.

The research team plans to continue testing and refining their machine learning models with the goal of developing an application that clinicians can use to identify patients at risk for developing kidney disease. Such a tool could help doctors prioritize which COVID-19 survivors need the most intensive monitoring and intervention.

For now, the key takeaway is clear: if you had COVID-19, especially if you also have diabetes, high blood pressure, or other risk factors, discussing kidney health monitoring with your doctor is an important step in protecting your long-term health. Early detection of kidney problems can lead to interventions that slow or prevent progression to more serious kidney disease.