Interactions between the principal risk factors for reduction of the eGFR in unvaccinated COVID‑19 survivors: Normal pre-COVID‑19 eGFR, not having diabetes and being hospitalized

There are contradictory results regarding changes in estimated glomerular filtration rate (eGFR) in coronavirus disease 2019 (COVID‑19) survivors. An analysis of eGFR changes and clinical characteristics associated with those changes was conducted among COVID‑19 survivors. eGFR values were compared at different time points (before and 4‑, 8‑ and 12‑months after COVID‑19 infection). A multivariate generalized linear mixed model (GENLINMIXED procedure) with a binary logistic regression link was used to determine factors associated with eGFR reduction of ≥10 ml/min/1.73 m2. Being hospitalized (RR=2.90, 95% CI=1.10‑7.68, P=0.032), treated with Ivermectin (RR=14.02, 95% CI=4.11‑47.80, P<0.001) or anticoagulants (RR=6.51, 95% CI=2.69‑15.73, P<0.001) are risk factors for a reduced eGFR. Having a low eGFR (<90 ml/min/1.73 m2) before COVID‑19 infection, having B‑positive blood type, diabetes, taking vitamin C during the acute phase of COVID‑19 or suffering from chronic COVID‑19 symptoms, were identified as protective factors. Analysis involving a two‑way interaction (A x B, where A and B are factors) demonstrated that the combination of patients with a normal eGFR value before COVID‑19 infection without diabetes (RR=58.60, 95% CI=11.62‑295.38, P<0.001), or a normal eGFR value with being hospitalized for COVID‑19 (RR=38.07, 95% CI=8.68‑167.00, P<0.001), increased the probability of a reduced eGFR. The changes in eGFR in COVID‑19 survivors varied depending on patient characteristics. Furthermore, the principal risk factors for post‑COVID‑19 eGFR reduction were analyzed in separate models.