Characteristics and Determinants of COVID-19-Associated AKI Among Patients of COVID-19 in Rivers State, Nigeria

Background: Severe acute respiratory coronavirus-2 (SARS-CoV-2)-induced coronavirus disease 2019 (COVID-19) is reportedly associated with acute renal injuries (AKI). However, this has been characterized majorly among Caucasians who have pre-existing confounding comorbidities that may also induce AKI, and hence, limit the conclusions of these previous studies. Consequently, the current study evaluated AKI incidence and associated factors among Nigerian COVID-19 patients of Negroid race who are without any pre-existing comorbid conditions. Methods: This was a retrospectively-designed observational study conducted among COVID-19 patients who presented at a COVID-19-designated treatment facility in Port Harcourt, Nigeria. Demographic, medical, and laboratory data obtained upon presentation were acquired and analyzed by AKI status using descriptive and inferential statistics. Results: Upon presentation, AKI occurred among 46.4% (n=181) of the entire studied population (n=390) which were majorly of stage 1, etiologically pre-renal, community-acquired, and of transient clinical course. Most of the AKI occurred among males, those with severe COVID-19 variants, and those who are unvaccinated against the disease. Those with COVID-19-associated AKI also had higher levels of peak plasma creatinine, plasma C-reactive protein, serum D-dimer, plasma osmolality, proteinuria, and hematuria but lower levels of within 24-hour urine volume, urine specific gravity, and urine osmolality compared to the non-AKI sub-group upon presentation. However, AKI patients with concurrent severe COVID-19 had a higher preponderance of stage 3, intra-renal and persistent AKI compared to patients with non-severe COVID-19 disease. In multivariate models, severe COVID-19 variant (OR: 6.017; CI: 5.880–6.422; p<0.001), the need for ICU transfer/treatment (OR: 3.210; CI: 3.119–3.341; p<0.001), serum D-dimer levels (OR: 3.967; CI: 3.688-4.297; p<0.001), and proteinuria (OR: 2.008; CI: 1.971–2.174; p=0.002) were independent risk factors for AKI among the studied population. Conclusion: AKI is common among COVID-19 patients independent of pre-existing comorbidities. The various COVID-19-associated AKI risk factors identified in the current study are valuable parameters that may guide clinical management among COVID-19 patients.