Association between ionized calcium levels and 3-months mortality in geriatric patients hospitalized for COVID-19

The aim of this study was to determine an association between ionized calcium (CaI) levels and mortality 3 months after Covid-19 infection in geriatric population. Observational retrospective cohort study. One hundred and seventy-nine patients hospitalized in the geriatric acute care unit of Angers University Hospital were included. This specific unit specifically dedicated to COVID-19 patients was opened for 2 periods : from March 1, 2020 to June 30, 2020 and from October 1, 2020 to March 29, 2021. Covariates considered were: age, sex, Iso-Resources Groups (GIR) score ≤ 3, Parathyroid hormone (PTH), C-Reactive Protein (CRP), severe undernutrition defined as albumin < 30 g/L, history of cancer, history of cardiomyopathy, severe chronic renal failure (defined as clearance < 30 ml/min), Ordinal Scale for Clinical Improvement (OSCI) score, use of systemic corticosteroids and usual vitamin D supplementation. Direct potentiometry was also used as a covariate. The time elapsed between the diagnosis of COVID-19 and death was studied by survival curves calculated using Cox model in each group defined by serum CaI concentration (>1.22 and ≤1.22 mmol/L). In the Cox model, a significant association was found between CaI over 1.22 mmol/l and 3-months mortality, analyzed in an adjusted model (HR 2.40 [1.34-4.31], p = 0.003). There is an association between CaI and 3 months mortality in geriatric patients hospitalized for COVID-19.