Endocrine Abstracts

Coronavirus disease 2019 (COVID-19), may lead to a severe acute respiratory syndrome requiring hospitalization and assisted ventilation with high lethality. Replication of SARS-CoV, MERS-CoV and Ebolavirus is calcium-dependent and hypocalcemia has been frequently reported in all these infections. Despite already many studies reporting on clinical and laboratory presentation of COVID-19 patients, including inflammatory and organ injury biomarkers, only one case report has so far described hypocalcemia in COVID-19. The aim of our study was to investigate the incidence of hypocalcemia in a large single center population of COVID-19 patients and evaluate its clinical implications. We retrospectively included 531 COVID-19 patients (aged ≥ 18 years) with serum ionized calcium (Ca²⁺) evaluation from arterial blood gas test (ABG) performed at initial evaluation in our Emergency Departments (ED). We collected two different Ca²⁺ levels, a real level (“actual calcium (AC)”) and a corrected for a pH 7.4 (“standardized calcium (SC)”). Hypocalcemia was defined as a calcium levels below 1.18 mmol/l. We excluded patients with comorbidities and concomitant therapies influencing calcium metabolism. Hypocalcemia was found in 462 patients (82%) with AC levels and in 414 (78.6%) patients with SC levels. Severe hypocalcemia (below 0.99 mmol/l) was found in 18 (AC, 3.4%) and 10 (SC, 1.9%) patients. Hypocalcemic patients were more frequently males (AC, 69% vs 57% P = 0.06; SC, 70% vs 60% P = 0.046) and older (AC, 59 yr [51–69] vs 53 [45-67] P = 0.01). LDH and PCR levels were very significantly higher in hypocalcemic vs normocalcemic patients (AC, LDH: 372 U/l [287–466] vs 271.5 [202.25–347.5] P < 0.001; PCR: 71.55 mg/dl [31.22–132.4] vs 24 [4.65–77.65] P <0.001; SC, LDH 70.25 mg/dl [30.87–130.35] vs 38 [11.2–105.9] P < 0.001; PCR 377 U/l [289–467] vs 307 [236–399] P < 0.001). In univariate and multivariate analyses hypocalcemia was an independent risk factor associated with hospitalization. Fifty-eight patients died (11.5%) and 62 (11.7%) were admitted in ICU. Hypocalcemia at admission was significantly associated to these two outcomes only in univariate but not in multivariate analyses. To our knowledge this is the first study that reports very high incidence of hypocalcemia in a large monocentric population of COVID-19 patients at initial hospital evaluation. Since hypocalcemia is highly incident in COVID-19 patients, predicts the need for hospitalization and may be life threatening if severe potentially worsening the COVID-19 morbidity at the cardiovascular level we suggest that ionized calcium should always be assessed at initial hospital evaluation, monitored and eventually adequately treated in all COVID-19 patients.