Correlation Between Biomarkers and Age-Adjusted Charlson Comorbidity Index in Patients With COVID-19: A Cross-Sectional Study in a Tertiary Care Center in South India

Background Coronaviruses, generally known to cause a mild degree of respiratory illness have in the recent past caused three serious disease outbreaks. The world is yet to be released from the grip of the most recent coronavirus disease 2019 (COVID-19) pandemic due to emerging mutant strains. Age, presence of comorbidities, clinical severity, and laboratory markers such as C-reactive protein and D-dimer are some of the factors being employed to prioritize patients for hospital care. It is known that comorbidities themselves are an outcome of inflammation and can induce a pro-inflammatory state. Our study aims to elucidate the influence of age and comorbidities on laboratory markers in patients with COVID-19. Methodology This is a single-center retrospective study of patients with a laboratory diagnosis of COVID-19 admitted to our hospital between September 21, 2020, and October 1, 2020. A total of 387 patients above the age of 18 years were included in the analysis and categorized based on the age-adjusted Charlson comorbidity index (ACCI) score into group A (score ≤4) and group B (score >4). Demographic, clinical, and laboratory factors as well as outcomes were compared. Results Group B exhibited higher intensive care unit admission and mortality, as well as statistically significant higher mean values of most laboratory markers. A correlation was also observed between the ACCI score and biomarker values. On comparison between the two groups regarding cut-offs predicting mortality for laboratory determinants, no consistent pattern was observed. Conclusions A correlation between age, the number of comorbidities, and laboratory markers was observed in our analysis of COVID-19-affected patients. Aging and comorbid conditions can produce a state of meta-inflammation and can thereby contribute to hyperinflammation in COVID-19. This can be an explanation for the higher risk of COVID-19-related mortality in older individuals and those with underlying comorbidities.