Associated Factors and Outcomes of Acute Kidney Injury in COVID-19 Patients in Kenya

Corona Virus Disease 2019 (COVID-19), an infection caused by the SARS-CoV-2 virus, has been the largest global pandemic since the turn of the 21st century. With emerging research on this novel virus, studies from the African continent have been few. Corona Virus Disease 2019 has been shown to affect various organs including the lungs, gut, nervous system, and the kidneys. Acute kidney injury (AKI) is an independent risk factor for mortality and increases the health care burden for patients with persistent kidney dysfunction and maintenance dialysis. Sub-Saharan Africa has a high number of poorly controlled chronic illnesses, economic inequalities, and health system strains that may contribute to higher cases of kidney injury in patients with COVID-19 disease.

The objective of this study was to determine the incidence, associated factors, and outcomes of AKI in patients hospitalized with COVID-19 in Kenya.

This retrospective cohort study included 1366 patients with confirmed COVID-19 illness hospitalized at the Aga Khan University Hospital in Nairobi, Kenya, between April 1, 2020 and October 31, 2021. Data were collected on age, sex, the severity of COVID-19 illness, existing pregnancy and comorbid conditions including human immunodeficiency virus (HIV), diabetes mellitus, hypertension, and functioning kidney transplant patients. Univariate analysis was carried out to determine the association of clinical and demographic factors with AKI. To determine independent associations with AKI incidence, a logistic regression model was used and the relationship was reported as odds ratios (ORs) with a 95% confidence interval (CI). The outcomes of AKI including the in-hospital mortality rate, renal recovery rate at hospital discharge, and the duration of hospital stay were reported and stratified based on the stage of AKI.

The median age of study patients was 56 years (interquartile range [IQR] = 45-68 years), with 67% of them being male (914 of 1366). The AKI incidence rate was 21.6% (n = 295). Patients with AKI were older (median age = 64 years vs 54 years; P < .001), majority male (79% of men with AKI vs 63.6% without AKI; P < .001), and likely to have a critical COVID-19 (OR = 8.03, 95% CI = 5.56-11.60; P < .001). Diabetes and hypertension, with an adjusted OR of 1.75 (95% CI = 1.34-2.30; P < .001) and 1.68 (95% CI = 1.27-2.23; P < .001), respectively, were associated with AKI occurrence in COVID-19. Human immunodeficiency virus, pregnancy, and a history of renal transplant were not significantly associated with increased AKI risk in this study. Patients with AKI had significantly higher odds of mortality, and this effect was proportional to the stage of AKI (OR = 11.35, 95% CI = 7.56-17.03; P < .001). 95% of patients with stage 1 AKI had complete renal recovery vs 33% of patients with stage 3 AKI. Of the patients with stage 3 AKI (n = 64), 10 underwent hemodialysis, with 1 recovery in renal function and 3 patients requiring ongoing dialysis after discharge.

This study was conducted at a single private tertiary-level health care facility in Kenya and only up to the time of hospital discharge. It is one of the first large studies from sub-Saharan Africa looking at the associated factors and outcomes of AKI in COVID-19 and forms a foundation for further analysis on the long-term consequences of COVID-19 on the kidneys. A major limitation of the study is the lack of baseline pre-admission creatinine values for most patients; thus, the impact of chronic kidney disease/baseline creatinine values on the incidence of AKI could not be established.