Impact of COVID-19 on Renal Function: A Multivariate Analysis of Biochemical and Immunological Markers in Patients

Introduction There have been tremendous continuous efforts to understand the broad spectrum of disease and its sequelae since the start of the coronavirus disease 2019 (COVID-19) pandemic. Several studies have identified biomarkers that correlate with multiple organ failure in COVID-19 patients. The purpose of our study was to evaluate COVID-19-associated kidney injury. Methods This retrospective cross-sectional study was conducted at the Institute of Biochemistry, Madras Medical College, by reviewing the electronic records of 1,000 reverse transcription-polymerase chain reaction (RT-PCR)-confirmed COVID-19-positive patients admitted at the COVID-19 care center. Data were extracted from the case records of 1,000 RT-PCR-positive patients with different CT chest grades plus comorbid conditions such as type 2 diabetes mellitus (T2DM), systemic hypertension (SHT), coronary artery disease (CAD), chronic obstructive pulmonary disease (COPD), and cerebrovascular accident (CVA) as Group I (n = 500). Group II (n = 500) comprised of COVID-19-positive patients with no comorbid conditions. The data were recorded from all the patients at the time of admission, prior to starting treatment. Patients with comorbid and non-comorbid conditions were compared according to different CT grades. Results COVID-19 patients with different CT grades showed a significant relationship with creatinine, sodium, potassium, C-reactive protein (CRP), ferritin, total protein, and albumin with p-values of 0.04, 0.01, 0.02, 0.000, 0.00, 0.00, and 0.000, respectively, in Group I. In Group II, with various grades of CT changes, the neutrophil-lymphocyte ratio (NLR) and creatinine showed no significance. The sodium, potassium, CRP, ferritin, total protein, and albumin showed low significance with the chest CT grades. Conclusions Our study demonstrated that COVID-19 can cause mild to moderate renal impairment in COVID-19 patients. Multiple factors contributed to this, such as the higher angiotensin-converting enzyme 2 (ACE2) expression on kidney cells, microinflammation, increased blood clotting, and probable direct infection of the kidney. A high NLR, increased inflammatory markers, and altered renal function analytes such as urea, creatinine, sodium, potassium, total protein, and albumin also confirmed this.