Taiwanese Study Warns That COVID-19 Quietly Triggers Long-Term Kidney Damage Even Without Initial Kidney Injury!

Medical News: A new study by researchers from several top Taiwanese medical institutions has uncovered a disturbing link between COVID-19 infection and the silent progression of chronic kidney disease (CKD), even in patients who showed no signs of acute kidney injury (AKI) during their initial illness. The research, conducted by experts from Chi Mei Medical Center in Tainan City, National Sun Yat-sen University in Kaohsiung, E-Da Hospital at I-Shou University, and Chia Nan University of Pharmacy and Science, compared long-term kidney outcomes in patients who had COVID-19 to those who had influenza, revealing that COVID-19 survivors are at a significantly higher risk of developing serious kidney problems over time.


Taiwanese Study Warns That COVID-19 Quietly Triggers Long-Term Kidney Damage Even
Without Initial Kidney Injury!

While earlier reports have focused on AKI as a frequent and deadly complication of COVID-19, many believed that if patients didn’t suffer from kidney issues during their acute illness, their risk was minimal. However, this Medical News report highlights new evidence to the contrary.
 
The Study Design
Using the TriNetX global healthcare database, which collects anonymized health records from 133 hospitals and medical centers - mostly in the United States - the researchers conducted a large-scale retrospective study. They carefully matched 141,587 COVID-19 patients with an equal number of influenza patients based on age, gender, race, existing health conditions, and lab results, making the two groups as comparable as possible. Importantly, they excluded anyone who showed signs of kidney problems within one month of infection to isolate long-term effects only.
 
The main goal of the study was to determine how many patients developed advanced chronic kidney disease - defined as CKD stages 3 to 5 - within a year of their infection. They also tracked who later developed AKI or had reduced kidney filtration function (eGFR below 60 mL/min/1.73m²), an important marker of kidney health.
 
What the Study Found
The results were alarming. COVID-19 patients had more than double the risk of developing advanced CKD within 12 months compared to those who had influenza. Specifically, 0.25% of COVID-19 patients developed advanced CKD versus 0.13% in the influenza group. The hazard ratio (HR) stood at 2.02, meaning COVID patients were twice as likely to suffer serious kidney decline.
 
The risk was even more dramatic for other kidney-related complications. COVID-19 patients were over three times more likely to suffer from AKI and reduced eGFR within a year. For example, 1.23% of COVID-19 patients experienced reduced kidney filtration compared to just 0.43% of influenza patients (HR 3.01).
 
These findings held up across subgroups, especially in men and older adults. In patients over 45 years of age, COVID-19 was associated with a 3.46-fold higher risk of AKI and more than double the risk of CKD compared to their influenza counterparts. While younger adu lts (18 to 45) also had increased risks of kidney damage markers like reduced eGFR, the progression to full-blown CKD was not statistically significant in this group.
 
Why It Matters
This study challenges the common assumption that only severe COVID-19 cases result in long-term organ damage. Even in those who did not require hospitalization or had no kidney issues during their acute infection, the virus appears to trigger long-lasting effects that silently compromise kidney health.
 
One possible explanation is that SARS-CoV-2 - the virus that causes COVID-19 - can directly infect kidney tissues via ACE2 receptors, leading to chronic inflammation, fibrosis (scarring), and microvascular injury that accumulates over time. The virus can also disrupt immune and hormonal systems that normally protect the kidneys, creating a perfect storm for long-term damage.
 
Another striking discovery was that even after excluding all patients who developed AKI during follow-up, the increased risk of developing CKD persisted in the COVID group. This suggests that COVID-19 itself - not just the complications it can cause - might independently harm the kidneys.
 
Risk Factors That Worsen the Outlook
The researchers also identified which patients are most vulnerable. Diabetes and high blood pressure were the strongest predictors of developing advanced CKD after COVID-19. Other contributing factors included male gender, older age, malnutrition, obesity, and cancer.
 
Men were particularly susceptible to AKI, with a hazard ratio of 3.78 compared to 2.27 for women. This gender gap may point to differences in immune responses or hormonal influences, but more studies are needed to clarify the reasons.
Interestingly, early hospitalization after COVID-19 diagnosis was associated with a higher risk of later kidney problems, even if the patient recovered quickly. However, this did not necessarily translate to a higher risk of advanced CKD, hinting at complex underlying mechanisms that still need to be unraveled.
 
Conclusions
The study sends a powerful warning to the global medical community and general public: COVID-19 may have long-term consequences that extend far beyond the lungs, even in people who seem to recover without complications. Hidden kidney damage is a very real possibility, especially in older adults and those with existing health conditions like diabetes or hypertension.
 
Therefore, routine monitoring of kidney function - especially eGFR levels - is strongly recommended in COVID-19 survivors, even if they had no initial symptoms involving the kidneys. Early detection and lifestyle changes may help prevent progression to irreversible kidney failure and dialysis dependency.
 
The study findings were published in the peer-reviewed journal: Scientific Reports.
https://link.springer.com/article/10.1038/s41598-025-96032-4
 
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Read Also:
https://www.thailandmedical.news/news/how-covid-19-impacts-kidney-health-and-increases-risk-of-chronic-kidney-disease
 
https://www.thailandmedical.news/news/study-sounds-alarm-that-covid-19-is-causing-decline-in-kidney-function
 
https://www.thailandmedical.news/news/study-warns-that-the-deposition-of-sars-cov-2-protein-in-the-kidneys-are-worsening-post-covid-renal-conditions
 
https://www.thailandmedical.news/articles/coronavirus
 
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https://www.thailandmedical.news/articles/long-covid