Anaemia of acute inflammation: a higher acute systemic inflammatory response is associated with a larger decrease in blood haemoglobin levels in patients with COVID-19 infection

• Published in: Clinical medicine (London, England) Vol. 23; no. 3; pp. 201 - 205
• Main Authors: Crooks, Colin J, West, Joe, Morling, Joanne R, Simmonds, Mark, Juurlink, Irene, Briggs, Steve, Cruickshank, Simon, Hammond-Pears, Susan, Shaw, Dominick, Card, Timothy R, Fogarty, Andrew W
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.05.2023; Royal College of Physicians
• Subjects: anaemia; Anemia; Blood tests; Confidence intervals; Coronaviruses; COVID-19; Hemoglobin; Hemoglobins - metabolism; Humans; Hypotheses; infection; Infections; Infectious diseases; Inflammation; Length of stay; Male; Middle Aged; Patients; Regression analysis; Systemic Inflammatory Response Syndrome; United Kingdom > UK; COVID-19; infection; anaemia; inflammation
• ISSN: 1470-2118; 1473-4893
• DOI: 10.7861/clinmed.2022-0436

The study tests the hypothesis that a higher acute systemic inflammatory response was associated with a larger decrease in blood hemoglobin levels in patients with Coronavirus 2019 (COVID-19) infection. All patients with either suspected or confirmed COVID-19 infection admitted to a busy UK hospital from February 2020 to December 2021 provided data for analysis. The exposure of interest was maximal serum C-reactive protein (CRP) level after COVID-19 during the same admission. A maximal serum CRP >175mg/L was associated with a decrease in blood haemoglobin (−5.0 g/L, 95% confidence interval: −5.9 to −4.2) after adjustment for covariates, including the number of times blood was drawn for analysis. Clinically, for a 55-year-old male patient with a maximum haemoglobin of 150 g/L who was admitted for a 28-day admission, a peak CRP >175 mg/L would be associated with an 11 g/L decrease in blood haemoglobin, compared with only 6 g/L if the maximal CRP was <4 mg/L. A higher acute systemic inflammatory response is associated with larger decreases in blood haemoglobin levels in patients with COVID-19. This represents an example of anaemia of acute inflammation, and a potential mechanism by which severe disease can increase morbidity and mortality.