Are patients with Covid-19 at risk of long-term chronic kidney disease?

The relationship between Coronavirus Disease 2019 (COVID-19) and acute kidney injury (AKI) is well-established. However, a comprehensive evaluation of kidney outcomes in the long-term course of COVID-19 is not yet been performed. The aim of this study is to investigate whether chronic kidney disease (CKD) develops within six months after hospital discharge in COVID-19 patients who did not have kidney damage at the time of admission to the hospital.

This single-center retrospective study investigated a total of 1008 participants selected from 7500 COVID-19 patients with real-time reverse transcription-polymerase chain reaction (RT-PCR) positivity. All patients had mild/moderate or severe COVID-19. Patients were randomly selected from inpatient and outpatient settings. Critical COVID-19 patients were not included.

The mean age of the patients was 56.57 ± 16.30 years, and 69.9% of them were male. The comorbidity percentages of the participants were as follows; 19.5% coronary artery disease (CAD), 28.6% diabetes mellitus (DM), 36.2% hypertension (HT), 3.1% cerebrovascular obstruction (CVO), 1.7% malignancy, 2.6% chronic obstructive pulmonary disease (COPD), 9.4% asthma, % 1.7 dementia, 9.9% hyperlipidaemia, and 1.7% hepatitis B virus (HBV). Kidney function tests of these patients at first admission and 6 months later were compared to reveal the relationship between COVID-19 and CKD. Serum glucose, sodium estimated glomerular filtration rate (eGFR), and uric acid levels were found to be high in the post-COVID-19 period (P = 0.001). However, there were a decrease in serum albumin, potassium, alanine aminotransferase (ALT), C-reactive protein (CRP), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), and gamma-glutamyl transferase (GGT) levels (P = 0.001). The difference between the first measurement of serum urea and creatinine (Cr) levels and the measurement 6 months later was not statistically significant (P = 0.102 and P = 0.300, respectively).

Those who survived the mild/moderate and severe clinical manifestations of COVID-19 did not exhibit any risk of kidney outcomes after the acute phase of the disease, suggesting that the kidney can protect itself over a long period of time.