Association between Hypocalcemia and Outcome in COVID-19 Patients: A Retrospective Study

Background  Calcium has been shown to play a vital role in the pathophysiology of severe acute respiratory syndrome-coronavirus-2 and middle east respiratory syndrome coronavirus diseases, but less is known about hypocalcemia in coronavirus disease 2019 (COVID-19) patients and its association with the disease severity and the final outcome. Therefore, this study was conducted with an aim to assess clinical features in COVID-19 patients having hypocalcemia and to observe its impact on COVID-19 disease severity and the final outcome. Methods  In this retrospective study, consecutive COVID-19 patients of all age groups were enrolled. Demographical, clinical, and laboratory details were collected and analyzed. On the basis of albumin-corrected calcium levels, patients were classified into normocalcemic ( n  = 51) and hypocalcemic ( n  = 110) groups. Death was the primary outcome. Results  The mean age of patients in the hypocalcemic group was significantly lower ( p  < 0.05). A significantly higher number of hypocalcemic patients had severe COVID-19 infection (92.73%; p  < 0.01), had comorbidities (82.73%, p  < 0.05), and required ventilator support (39.09%; p  < 0.01) compared with normocalcemic patients. The mortality rate was significantly higher in the hypocalcemic patients (33.63%; p  < 0.05). Hemoglobin ( p  < 0.01), hematocrit ( p  < 0.01), and red cell count ( p  < 0.01) were significantly lower with higher levels of absolute neutrophil count (ANC; p  < 0.05) and neutrophil-to-lymphocyte ratio (NLR; p  < 0.01) in the hypocalcemic patients. Albumin-corrected calcium levels had a significant positive correlation with hemoglobin levels, hematocrit, red cell count, total protein, albumin, and albumin-to-globulin ratio and a significant negative correlation with ANC and NLR. Conclusion  The disease severity, ventilator requirement, and mortality were considerably higher in hypocalcemic COVID-19 patients.